Appendix A

The Literature of Organic Chemistry

All discoveries in the laboratory must be published somewhere if the information is to be made available to the scientific community. A new experimental result that is not published is useless, insofar as it benefits the entire chemical world. Traditionally, the total body of chemical knowledge (called the literature) is located on the combined shelves of all the chemical libraries in the world. Nowadays, books remain on library shelves, but many, if not most, chemical journals are available online. As e-books become increasingly available, however, books will be available online or for personal electronic reading devices. Anyone who wishes to learn the answer to a chemical question will access the chemical literature, both books and original articles in journals. The expressions “is known”, “has been done”, and so on, usually means “has been published”. The contents of the scientific literature may appear formidably large, but the process of extracting information from the literature of organic chemistry is usually manageable. Appendix A examines both the print literature of organic chemistry¹ and, within reasonable limits, electronic forms of the literature.

It is quite clear that the literature can be divided into two broad categories: primary sources and secondary sources. A primary source publishes the original results of laboratory investigations, usually in scientific journals. Indeed, the two chief kinds of primary source are journals and patents. Books, indexes, and other publications that cover material that has previously been published in primary sources are called secondary sources. Electronic search engines that use primary sources as a database are also considered to be secondary sources. It is because of the excellence of the secondary sources in organic chemistry (especially Chemical Abstracts, SciFinder) that literature searching is comparatively straightforward.

A. Primary Sources

A.i. Journals

For well over 100 years, nearly all new work in organic chemistry (except for that disclosed in patents) has been published in journals. There are many journals that publish chemical papers, in many countries and in many languages. Nowadays, a high percentage of the journals are published in English, but not all. Some print papers cover all fields of science; some are restricted to chemistry; some to organic chemistry; and some are still more specialized. As noted above, many journals are now available in electronic form.² The actual article is usually offered as an html file, or a PDF file, often with links to the cited references. The vast majority of important papers in “pure” organic chemistry (as opposed to “applied”) are published in relatively few journals, perhaps 50 or fewer. The concept of “pure” organic chemistry is not as useful nowadays because organic chemistry is important in many areas, and multidisciplinary research often includes organic chemistry. Literature that is important to an organic chemist is found in journals and patents that focus on bioorganic, organometallic, materials science, polymer science, separation science, medicinal chemistry, pharmaceutical sciences, and medicine to name a few. The reader is therefore cautioned that the journals listed in this section have organic chemistry as their primary focus, but are by no means the only sources of information concerning organic chemistry. The literature is vast and many journals are published weekly and some semimonthly.

Ordinary papers, usually referred to as full papers, usually include full experimental details, either as part of the paper itself or as accompanying supplemental information. Such details are the mainstay of modern research, providing a guide to what has been done, and the experimental details allow one to repeat that work. With the increase in the volume of chemical literature, and especially with the proliferation of electronic journals, and as noted above, many journals now place full experimental details into “Supplemental Information”. For journals published by the American Chemical Society, a URL link is provided for each article that contains the supplemental information: experiential details, spectral data, visual reproductions of spectral data, X-ray crystallographic data, and so on. Other publishers offer similar links. Once a paper is accepted, the online version (e.g., American Chemical Society ASAP papers) can be found before the print version or the full electronic version that contains the page numbers appear.

In addition to full papers, there are two other types of publications in which original work is reported: notes and communications. A note is a brief paper, often without a summary (nearly all papers are published with summaries or abstracts prepared by the author). Otherwise, a note is similar to a paper.³ Some journals specialize in publishing only notes. Communications (also called letters) are also brief and are usually without summaries (some journals now publish summaries along with their communications), and there are journals that publish only communications or letters.

Communications differ from notes and papers in three respects:

1. They are brief, not because the work is of small scope, but because they are condensed. Usually they include only the most important experimental details or none at all.

2. They are often of immediate significance. Journals that publish communications make every effort to have them appear as soon as possible after they are received. With modern computer technology, communications can often be published in a matter of weeks.

3. Communications are preliminary reports, and the material in them may be republished as papers at a later date, in contrast to the material in papers and notes, which cannot be republished.

Although chemical publications are published in many languages, the vast majority of important papers in organic chemistry are published in English. For example, six prominent European journals (Chemische Berichte, Liebigs Annalen der Chemie, Bulletin de la Société Chimique de France, Bulletin des Sociétés Chimique Belges, Recueil des Travaux Chimiques des Pays-Bas, and Gazzetta Chimica Italiana) were discontinued. In their place is the European Journal of Organic Chemistry, published in English. Most of the articles published in other languages have summaries printed in English also. Important papers were published in German and French for >200 years, and these are generally not available in translation, so that the organic chemist was required to have at least a reading knowledge of these languages. Before ~1920, more than one-half of the important chemical papers were in these languages. In recent years, however, fewer papers in French or German have appeared without an English translation. Of course, a reading knowledge of French and German (especially German) is critical for the older literature. It must be realized that the original literature is never obsolete. With the rise of China in the scientific community, journals are published in Chinese, and there are journals and important chemical discoveries published in Japanese. Work by Chinese and Japanese scientists regularly appears in English-language journals. Secondary sources become superseded or outdated, but nineteenth century journals with primary literature are found in most chemical libraries and are still consulted. Table A.1 presents a list of important current journals that publish original papers⁴ and communications in organic chemistry. Some of them also publish review articles, book reviews, and other material. In 1999, the Journal of Organic Chemistry stopped publishing communications, and these are now published in Organic Letters.

Table A.1 A List of the More Important Current Journals^a

For some years, the American Chemical Society journals, including J. Am. Chem. Soc. and J. Org. Chem., provided supplementary material for some of their papers on microfilm or microfiche. As noted above, this material is now available online, and for older literature from the Microforms and Back Issues Office at the ACS Washington office, either on microfiche, or as a photocopy. These practices have not yet succeeded in substantially reducing the total volume of the world's primary chemical literature since many new journals have appeared, and the yearly page count for most journals has doubled or tripled.

A.ii. Patents

In many countries, including the United States, it is possible to patent a new compound or a new method for making a known compound (either laboratory or industrial procedures). It comes as a surprise to many to learn that a substantial proportion of the patents granted (perhaps 20–30%) have been chemical patents. Chemical patents are part of the chemical literature, and both U.S. and foreign patents were regularly abstracted by Chemical Abstracts and now SciFinder. In addition to learning about the contents of patents from this source, chemists may consult the Official Gazette of the U.S. Patent Office, which, published weekly and available in many libraries, lists titles of all patents issued that week. Bound volumes of all U.S. patents are kept in a number of large libraries, including the New York Public Library, which also has an extensive collection of foreign patents. Photocopies of any U.S. patent and most foreign patents were obtained at low cost from the U.S. Patent and Trademark Office, Washington, DC, 20231. Many patents can now be obtained online as well or are available as PDF files. Patents are also available via SciFinder (formerly, CAS online).

Although patents are often very useful to the laboratory chemist, and no literature search is complete that neglects relevant patents, as a rule they are not as reliable as papers. There are two reasons for this finding:

1. It is in the interest of the inventor to claim as much as possible. The patent may show, for example, that a reaction was actually carried with ethanol and with 1-propanol, but will claim all primary alcohols, and perhaps even secondary and tertiary alcohols, glycols, and phenols. An investigator repeating the reaction on an alcohol that the inventor did not use may find that the reaction gives no yield at all. In general, it is safest to duplicate the actual examples given, of which most chemical patents contain one or more.

2. Although legally a patent gives an inventor a monopoly, any alleged infringements must be protected in court, and this may cost a good deal of money. Therefore some patents are written so that certain essential details are concealed or entirely omitted. A patent is supposed to be a full disclosure, but patent attorneys are generally skilled in the art of writing patents, and procedures given are not always sufficient to duplicate the results.

Fortunately, the above statements do not apply to all chemical patents: many make full disclosures and claim only what was actually done. It must also be pointed out that it is not always possible to duplicate the work reported in every paper in a journal due to the use of proprietary catalysts or equipment not available to the public. It is not uncommon to literally purchase the world's supply of a key ingredient. Note, however, that some work is not published or patented but rather maintained within the company as a trade secret. Such work is not, of course, available to the public.

B. Secondary Sources

Journal articles and patents contain virtually all of the original work in organic chemistry. However, if this were all, if there were no indexes, abstracts, review articles, and other secondary sources, the literature would be unusable, because it is so vast that no one could hope to find anything in particular. Fortunately, the secondary sources are excellent. There are various kinds and the classification shown here is somewhat arbitrary.

B.i. Listings of Titles

The profusion of original papers is so great that publications that list the titles of current papers find much use. Such lists are primarily methods of alerting the chemist to useful papers published in journals that are not normally read. This approach using print versions containing lists or journals and articles is used sparingly nowadays. Most journals are available online with useful search engines, and most have the original papers, with supplemental material, as html and PDF¹¹ documents. The PDF document can be downloaded to the searcher's desktop, sometimes for a fee, shipped to other scientists electronically, and is most convenient. Chemical Abstracts was available online as CAS OnLine, but this service has been supplanted by SciFinder (see Appendix A.D.iii). University libraries and companies pay the appropriate fees, so access to the journals is usually quite easy if one is affiliated with these organizations. Search engines allow one to quickly scan an enormous amount of literature from office or home. In addition, most browsers have online searching capabilities via various search engines, and simply typing in an author, a topic, a chemical, or a few keywords can lead to important articles or information. “Google® searching”¹² is commonly employed for a “quick and dirty” search, but one is strongly urged to use one of the established scientific search engines for a proper search. The more important online technology will be discussed below. However, some other resources¹³ include Specialty Citation Indexes Science Citation Index Expanded™, Web of Science®, Science Citation Index®, ISI ProceedingsSM, Reaction Citation Index™, and the Derwent Innovations IndexSM. The discussion will begin with the older print versions for chemical searches.

A print-version “title” publication covering the whole of chemistry is Current Contents Physical, Chemical & Earth Sciences,¹⁴ which began in 1967 and appears weekly, contains the contents pages of all issues of about 800 journals in chemistry, physics, earth sciences, mathematics, and allied sciences. Each issue contains an index of important words taken from the titles of the papers listed in that issue, and an author index, which, however, lists only the first-named author of each paper. The author's address is also given, so that one may write for reprints. An online service is available called Current Contents Connect® is a multidisciplinary Web resource providing access to complete bibliographic information from >8000 of the world's leading scholarly journals and >2000 books.¹⁵

Chemical titles is a similar publication produced by the Chemical Abstracts Service (CAS). SciFinder described below allows one to search a variety of databases, including journal titles.

B.ii. Abstracts

Listings of titles are valuable, as far as they go, but they do not tell what is in the paper, beyond the implications carried by the titles. Most current journals contain a graphic abstract, as well as a title and a brief print description of the research. The graphical abstract is extremely useful for scanning the literature presented in a journal, and both the print and graphical abstracts are available online for most journals.

From the earliest days of organic chemistry, abstracts of papers have been widely available, often as sections of journals whose principal interests lay elsewhere.¹⁶ At the present time there are only two publications entirely devoted to abstracts covering the whole field of chemistry. One of these, Referativnyi Zhurnal, Khimiya, which began in 1953, is published in Russian and is chiefly of interest to Russian-speaking chemists. The other is Chemical Abstracts, which was published until 2010. Abstracts are now available online via SciFinder. Although out of print, knowledge of Chemical Abstracts is important to properly do a literature search that includes older literature. Chemical Abstracts appeared weekly and printed abstracts in English of virtually every paper containing original work in pure or applied chemistry published anywhere in the world.¹⁷ More than 18,000 journals were covered, in many languages. In addition, CA published abstracts of every patent of chemical interest from 18 countries, as well as many patents from additional countries. The abstracts currently appeared in 80 sections, with sections 21–34 devoted to organic chemistry, under such headings as Alicyclic Compounds, Alkaloids, Physical Organic Chemistry, Heterocyclic Compounds (One Heteroatom), and so on. Each abstract of a paper had a heading that gave (1) the abstract number;¹⁸ (2) the title of the paper; (3) the authors' names as given in the paper; (4) the authors' address; (5) the abbreviated name of the journal (see Table A.1);¹⁹ (6) the year, volume, issue, and page numbers; and (7) the language of the paper. In earlier years CA gave the language only if it differed from the language of the journal title. Abstracts of patents showed the abstract number, title, inventor and company (if any), patent number, patent class number, date patent issued, country of priority, patent application number, date patent applied for, and number of pages in the patent. The body of the abstract contained a concise summary of the information in the paper. For many common journals, the author's summary (if there is one) was used in CA as it appeared in the original paper, with perhaps some editing and additional information. Each issue of CA contained an author index, a patent index, and an index of keywords taken from the titles and the texts or contexts of the abstracts. The patent index listed all patents in order of number. The same compound or method is often patented in several countries. Chemical Abstracts abstracted only the first patent, but listed the patent numbers of the duplicated patents in the patent index along with all previous patent numbers that correspond to it. Before 1981 there were separate Patent Number Indexes and Patent Concordances (the latter began in 1963).

At the end of each section of CA a list of cross-references to related papers in other sections is given.

Chemical Abstracts is useful as a repository of chemical information, a place for finding out what was done in the past. This value stems from the excellent indexes, which enable the chemist in most cases to ascertain quickly where information is located. From the time of its founding in 1907 until 1961, CA published annual indexes. After 1962 there were two volumes published each year, and a separate index is issued for each volume. Each volume contained an index of subjects, authors, formulas, and patent numbers. Beginning in 1972, the subject index was issued in two parts, a chemical substance index and a general subject index, which included all entries that are not the names of single chemical substances. However, the indexes to each volume were essentially superseded by each collective index. The first collective indexes were 10-year (decennial) indexes, but the volume of information made 5-year indexes necessary since 1956. Collective indexes so far published are shown in Table A.2.

Table A.2 CA Collective Indexes So Far Published.

As noted above, the print form of Chemical Abstracts has been superseded by SciFinder (see Appendix A.D.iii)

Beginning with the Eighth collective index period, CA has published an Index Guide. This publication gave structural formulas and/or alternate names for thousands of compounds, as well as many other cross-references. It was designed to help the user efficiently and rapidly to find CA references to subjects of interest in the general subject, formula, and chemical substance indexes. Each collective index contained its own Index Guide. The Index Guide was necessary because the CA general subject index was a “controlled index”, meaning it restricted its entries only to certain terms.

For example, anyone looking for the term “refraction” in the printed general subject index will not find it. The Index Guide included this term, and directed the reader to “Electromagnetic wave, refraction of”, “Sound and ultrasound, refraction of”, and other terms, all of which were found in the general subject index. Similarly, the chemical substance index usually listed a compound only under one name - the approved CA name. Trivial and other names were found in the Index Guide. For example, the term “methyl carbonate” is not in the chemical substance index, but the Index Guide does have this term, and directs the reader to the chemical substance index under the headings “carbonic acid, esters, dimethyl ester” (for Me₂CO₃) and “carbonic acid, esters, monomethyl ester” (for MeHCO₃). Furthermore, the Index Guide gives terms related to the chosen term, helping users to broaden a search. For example, one who looks for “Atomic orbital” in the Index Guide will find the terms “Energy Level”, “Molecular orbital”, “Atomic integral”, and “Exchange, quantum mechanical, integrals for”, all of which are controlled index terms.

Each index (annual, semiannual, or collective) also provided an index of ring systems. This valuable index enables the user to ascertain immediately if any ring system appears in the corresponding subject or chemical substance index and under what names. For example, someone wishing to determine whether any compounds

containing the benz(h)isoquinoline ring system are reported in the 1982–1986 collective index would locate, under the heading “3-ring systems”, the listing 6, 6, 6 (since the compound has three rings of six-members each), and would find the sublisting C₅N–C₆–C₆ (since one ring contains five carbons and a nitrogen while the others are all-carbon), under which is listed the name benz(h)isoquinoline, as well as the names of 30 other systems C₅N–C₆–C₆. A search of the chemical substance index under these names will give all references to these ring systems that appeared in CA from 1982 to 1986.

Nowadays, the drawing tools of SciFinder (sec. Appendix A.D.iii) are used to draw this structure, and then perform the search.

Before 1967, CA used a two-column page, with each column separately numbered. A row of letters from a to h appeared down the center of the page for the guidance of the user. Thus an entry 7337b refers to the b section of column 7337. In early years, superscript numbers (e.g., 4327⁵) were used in a similar manner. In very early years, these numbers were not printed on the page at all, though they are given in the decennial indexes, so that the user must mentally divide the page into nine parts. Beginning with 1967, abstracts are individually numbered and column numbers are discarded. Therefore, beginning with 1967, index entries give abstract number rather than column number. The abstract numbers are followed by a letter that serves as a check character to prevent miscopying errors in computer handling. To use the CA general subject, chemical substance, and formula indexes intelligently requires practice, and the student should become familiar with representative volumes of these indexes and with the introductory sections to them, as well as with the Index Guides.

In the CA formula indexes, formulas were listed in order of (1) number of carbon atoms; (2) number of hydrogen atoms; (3) other elements in alphabetic order. Thus, all C₃ compounds are listed before any C₄ compound; all C₅H₇ compounds before any C₅H₈ compound; C₇H₁₁Br before C₇H₁₁N; C₉H₆N₄S before C₉H₆O, and so on. Deuterium and tritium are represented by D and T and treated alphabetically (e.g., C₂H₅DO after C₂H₅Cl and before C₂H₅F or C₂H₆).

Since 1965, CA has assigned a Registry Number²⁰ to each unique chemical substance. This is a number of the form [766-51-8] that remains invariant, no matter what names are used in the literature. More than 64 million numbers have already been assigned and thousands are added each week. Registry Numbers are primarily for computer use, but chemical suppliers use CAS registry numbers to identify chemicals that are available for sale.

There were a number of earlier abstracting publications now defunct. The most important are Chemisches Zentralblatt and British Abstracts. These publications are still valuable because they began before CA and can therefore supply abstracts for papers that appeared before 1907. Furthermore, even for papers published after 1907, Zentralblatt and British Abstracts are often more detailed. Zentralblatt was published, under various names, from 1830 to 1969.²¹British Abstracts was a separate publication from 1926 to 1953, but earlier abstracts from this source are available in the Journal of the Chemical Society from 1871 to 1925.

B.iii. Beilstein

This publication has been so important to organic chemistry that it deserves a section by itself. Beilstein's Handbuch der Organischen Chemie, usually referred to as Beilstein, lists all the known organic compounds reported in the literature during its period of coverage. The print version will be described first, as it is particularly important for older literature.

For each compound in Beilstein, the following data are given: all names; the molecular formula; the structural formula; all methods of preparation (briefly, e.g., “by refluxing 1-butanol with NaBr and sulfuric acid”); physical constants (melting point, refractive index, etc.); other physical properties; chemical properties including reactions; occurrence in nature (i.e., which species it was isolated from); biological properties, if any; derivatives with melting points; analytical data, and any other information that has been reported in the literature.²² Equally important, for every piece of information, a reference is given to the original literature. Furthermore, the data in Beilstein have been critically evaluated. That is, all information is carefully researched and documented, and duplicate and erroneous results are eliminated. Some compounds are discussed in two or three lines and others require several pages.

The print editions are invaluable for searching older literature, but even today provide valuable data for many compounds used every day. A discussion of using Beilstein is therefore essential.

The first three editions of Beilstein are obsolete. The fourth edition (vierte Auflage) covers the literature from its beginnings through 1909. This edition, called das Hauptwerk, consists of 27 volumes. The compounds are arranged in order of a system too elaborate to discuss fully here.²³ The compounds are divided into three divisions that are further subdivided into “systems”:

Division	Volumes	System Numbers
I. Acyclic Compounds	1–4	1–499
II Carbocyclic Compounds	5–16	450–2359
III. Heterocyclic Compounds	17–27	2360–4720

Das Hauptwerk is still the basis of Beilstein and has not been superseded. The later literature is covered by supplements that have been arranged to parallel das Hauptwerk. The same system is used, so that the compounds are treated in the same order. The first supplement (erstes Ergänzungswerk) covers 1910–1919; the second supplement (zweites Ergänzungwerk) covers 1920–1929; the third supplement (drittes Ergänzungswerk) covers 1930–1949; the fourth supplement (viertes Ergänzungswerk) covers 1950–1959, and the fifth supplement covers 1960–1979. Like das Hauptwerk, each supplement contains 27 volumes,²⁴ except that supplements 3 and 4 are combined for Vols. 17–27, so that for these volumes the combined third and fourth supplement covers the years 1930–1959. Each supplement has been divided into volumes in the same way as das Hauptwerk, and, for example, compounds found in Vol. 3, system number 199 of das Hauptwerk will also be found in Vol. 3, system number 199 of each supplement. To make cross-referencing even easier, each supplement gives, for each compound, the page numbers at which the same compound can be found in the earlier books. Thus, on page 554 of Vol. 6 of the fourth supplement, under the listing phenetole are found the symbols (H 140; E I 80; E II 142; E III 545) indicating that earlier information on phenetole is given on page 140 of Vol. 6 of das Hauptwerk, on page 80 of the first, page 142 of the second, and page 545 of the third supplement. Furthermore, each page of the supplements contains, at the top center, the corresponding page numbers of das Hauptwerk. Since the same systematic order is followed in all six series, location of a compound in any one series gives its location in the other five. If a compound is found, for example, in Vol. 5 of das Hauptwerk, one has but to note the page number and scan Vol. 5 of each supplement until that number appears in the top center of the page (the same number often covers several pages). Of course, many compounds are found in only one, two, three, four, or five of the series, since no work may have been published on that compound during a particular period covered.

From das Hauptwerk to the fourth supplement, Beilstein is in German, but it is not difficult to read since most of the words are the names of compounds (a Beilstein German–English Dictionary, available free from the publisher, is in many libraries). For the fifth supplement (covering 1960–1979), which is in English, publication of Division III began before the earlier divisions. Volumes 17–22 (totaling 70 separate parts exclusive of index volumes) of this supplement have been published, as well as a combined index for volumes 17–19. This index covers only the fifth supplement. The subject portion of this index, which lists compound names only, gives these names in English.

Volumes 28 and 29 of Beilstein are subject and formula indexes, respectively. The most recent complete edition of these volumes is part of the second supplement and covers only das Hauptwerk and the first two supplements (though complete indexes covering das Hauptwerk and the first four supplements have been announced to appear in the next few years). For Vol. 1, there is a cumulative subject and a cumulative formula index, which combine das Hauptwerk and the first four supplements.²⁵ Similar index volumes, covering all four supplements, have been issued for the other volumes, 2–27. Some of these are combined (e.g., 2–3, 12–14, and 23–25). For English-speaking chemists (and probably for many German-speaking chemists) the formula indexes are more convenient. Of course (except for the fifth supplement indexes), one must still know some German, because most formula listings contain the names of many isomers. If a compound is found only in das Hauptwerk, the index listing is merely the volume and page numbers (e.g., 1, 501). Roman numbers are used to indicate the supplements (e.g., 26, 15, I 5, II 7). Thus the subject and formula indexes lead at once to locations in das Hauptwerk and the first four supplements. The Beilstein formula indexes are constructed the same way as the CA indexes (Appendix A.B.ii).

There is also a fourth division of Beilstein (systems 4721–4877) that covers natural products of uncertain structure: rubbers, sugars, and so on. These are treated in Vols. 30 and 31, which do not go beyond 1935 and that are covered in the collective indexes. These volumes will not be updated. All such compounds are now included in the regular Beilstein volumes.

In recent years, Beilstein was available online, with the useful search engine CrossFire. However, this database is now incorporated into Reaxys (see Appendix A.D.vi).

B.iv. Tables of Information

In addition to Beilstein, there are many other print reference works in organic chemistry that are essentially compilations of data. These books are very useful and often save the research worker a great deal of time. In this section, we discuss some of the more important of such works.

1. The sixth edition of Heilbron's Dictionary of Organic Compounds, J. Buckingham, Ed., 9 vols., Chapman and Hall, London, 1996, contains brief listings of >150,000 organic compounds, giving names, structural formulas, physical properties, and derivatives, with references. For many entries, additional data concerning occurrence, biological activity, and toxicity hazard information are also given. The arrangement is alphabetical. The dictionary contains indexes of names, formulas, heteroatoms, and CA Registry Numbers. Annual supplements, with cumulative indexes, have appeared since 1983. A similar work, devoted to organometallic compounds, is the 2nd edition of the Dictionary of Organometallic Compounds, 6 vols. in its 5th supplement, published by Chapman and Hall in 1989. Another, Dictionary of Steroids, 2 vols., 1991, is also published by Chapman and Hall.

2. A multivolume compendium of physical data is Zahlenwerte und Funktionen aus Physik, Chemie, Astronomie, Geophysik, und Technik, 6th ed., by H. Landolt and R. Börnstein, Springer, Berlin, 1950. There is also a “New Series”, for which the volumes are given the English title Numerical Data and Functional Relationships in Science and Technology, as well as the German title. This compendium, which is not yet complete, lists a great deal of data, some of which are of interest to organic chemists (e.g., indexes of refraction, heats of combustion, optical rotations, and spectral data). Literature references are given for all data.

3. The Handbook of Chemistry and Physics, CRC Press, Boca Raton, FL (called the “rubber handbook”), which is revised annually (92nd ed., 2011–2012), is a valuable repository of data quickly found. For organic chemists an important table is Physical Constants of Organic Compounds, which lists names, formulas, color, solubility, and physical properties of thousands of compounds. However, there are many other useful tables. A similar work is Lange's Handbook of Chemistry, 16th ed., McGraw-Hill, New York, 2004. Another such handbook, but restricted to data of interest to organic chemists, is Dean's Handbook of Organic Chemistry, 2nd ed., McGraw-Hill, New York, 2003. This book also contains a long table of Physical Constants of Organic Compounds, and has much other information including tables of thermodynamic properties, spectral peaks, pK_a values, bond distances, and dipole moments.

4. A list of most of the known natural compounds (e.g., terpenes, alkaloids, carbohydrates) to which structures have been assigned, along with structural formulas, melting points, optical rotations, and references, is provided in T.K. Devon and A.J. Scott, Handbook of Naturally Occurring Compounds, 3 vols., Academic Press, New York, 1972.

5. R.R. Dreisbach, Physical Properties of Chemical Compounds, Advances in Chemistry Series Nos. 15, 22, 29, American Chemical Society, Washington, 1955–1961 lists many physical properties of >1000 organic compounds.

6. Physical properties of thousands of organometallic compounds, with references, are collected in five large compendia: the Dictionary of Organometallic Compounds, mentioned under item 1, above; M. Dub, Organometallic Compounds, 2nd ed., 3 vols. with supplements and index, Springer, New York, 1966–1975; N. Hagihara, M. Kumada, and R. Okawara, Handbook of Organometallic Compounds, W.A. Benjamin, New York, 1968; and H.C. Kaufman, Handbook of Organometallic Compounds, Van Nostrand, Princeton, NJ, 1961; Comprehensive Organometallic Chemistry II, 14 vols, Pergamon, 1995.

7. The Merck Index, 14th ed., Merck and Company, Rahway, NJ, 2006 is a good source of information about chemicals of medicinal importance. Many drugs are given three types of name: chemical name (which is the name an organic chemist would give it; of course, there may well be more than one); generic name, which must be placed on all containers of the drug; and trade names, which are different for each company that markets the drug. For example, the generic name for 1-(4-chlorobenzhydryl)-4-methylpiperazine is chlorcyclazine. Among the trade names for this drug, which is an antihistamine, are Trihistan, Perazyl, and Alergicide. The Merck Index is especially valuable because it gives all known names of all three types for each compound and the names are cross-indexed. Also given, for each compound, are the structural formula, CA preferred name and Registry Number, physical properties, medicinal and other uses, toxicity indications, and references to methods of synthesis. There are indexes of formulas and Registry Numbers, and miscellaneous tables. The “Merck Index” also includes a lengthy list of organic name reactions, with references.

8. There are two publications that list properties of azeotropic mixtures. J. Timmermans, The Physico-chemical Constants of Binary Systems in Concentrated Solutions, 4 vols., Interscience, New York, 1959–1960, is by far the more comprehensive. The other is Azeotropic Data, 2 vols., Advances in Chemistry Series No. 6 and No. 35, American chemical Society, Washington, 1952, 1962.

9. Thousands of dipole moments, with references, are collected in V.A.L. McClellan, Tables of Experimental Dipole Moments, Vol. 1, W.H. Freeman, San Francisco, CA, 1963; Vol. 2, Rahara Enterprises, El Cerrita, CA, 1974.

10. Tables of Interatomic Distances and Configurations in Molecules and Ions, London Chemical Society Special publication no. 11, 1958, and its supplement, Special publication no. 18, 1965, include bond distances and angles for hundreds of compounds, along with references.

11. The Ring Systems Handbook, published in 1988 by the chemical Abstracts Service, provides the names and formulas of ring and cage systems that have been published in CA. The ring systems are listed under a system essentially the same as that used for the CA index of ring systems (sec. Appendix A.B.i, A.B.ii). Each entry gives the CA index name and Registry Number for that ring system. In many cases a CA reference is also given. There is a separate Formula Index (for the parent ring systems) and a Ring Name Index. Cumulative supplements are issued twice a year. The Ring Systems Handbook supersedes earlier publications called The Parent Compound Handbook and The Ring Index.

12. The Sadtler Research Laboratories published large collections of IR, UV, NMR, and other spectra, in loose-leaf form. Indexes are available.

13. Infrared, UV, NMR, Raman, and mass spectral data, as well as melting-point, boiling-point, solubility, density, and other data for >30,000 organic compounds are collected in the CRC Handbook of Data on Organic Compounds, 2nd ed., 9 vols., CRC Press, Boca Raton, FL, 1988, edited by R.C. Weast and J.G. Grasselli. It differs from the Sadtler collection in that the data are given in tabular form (lists of peaks) rather than reproduction of the actual spectra, but this book has the advantage that all the spectral and physical data for a given compound appear at one place. References are given to the Sadtler and other collections of spectra. Volumes 7–9 contain indexes of spectral peaks for IR, UV, NMR, NMR, mass, and Raman spectra, as well as indexes of other names, molecular formulas, molecular weights, and physical constants. Annual updates began appearing in 1990 (the first one is called volume 10).

14. The Aldrich Library of Infrared Spectra, 3rd ed., Aldrich Chemical Company, Milwaukee, WI, 1981, by Pouchert contains >12,000 IR spectra so arranged that the user could readily see the change that takes place in a given spectrum when a slight change is made in the structure of a molecule. The same company also publishes the Aldrich Library of FT-IR Spectra and the Aldrich Library of NMR Spectra, both also by C. Pouchert. A similar volume, which has IR and Raman spectra of ~1000 compounds, is Raman/Infrared Atlas of Organic Compounds, 2nd ed., VCH, New York, 1989, by B. Schrader.

15. An extensive list of visible and uv peaks is given in Organic Electronic Spectral Data, Wiley, New York. Twenty-six volumes have appeared so far, covering the literature through 1984.

16. A collection of 500 NMR spectra is found in L.F. Johnson and W.C. Jankowski, Carbon-13 NMR Spectra, Wiley, New York, 1972.

C. Reviews

A review article is an intensive survey of a rather narrow field. For example, the titles of some recent reviews are “Metathesis of Alkanes and Related Reactions”²⁶, “Potassium Organotrifluoroborates: New Perspectives in Organic Synthesis”²⁷, and “Asymmetric Addition of Allylic Nucleophiles to Imino Compounds”.²⁸ A good review article is of enormous value, because it is a thorough survey of all the work done in the field under discussion. Review articles are printed in review journals and in certain books. The most important review journals in organic chemistry (though most are not exclusively devoted to organic chemistry) are shown in Table A.3. Some of the journals listed in Table A.1, for example, Chemical Reviews, Accounts of Chemical Research, and Synlett, Tetrahedron, Synthesis, Organic Preparations and Procedures International, and J. Organomet. Chem. also publish occasional review articles. As with other journals, journals that contain reviews are available online.

Table A.3 Review Journals, with Year of Founding and Issues per Year.

Journal	Issues
Accounts of Chemical Research (1968)	12
Aldrichimica Acta (1968)	4
Angewandte Chemie (1888)	12
and its English Translation:
Angewandte Chemie, International Edition (1962)	12
Chemical Reviews (1924)	8
Chemical Society Reviews (1947)a	4
Heterocycles (1973)	12
Natural Product Reports (1984)	6
Organic Preparations and Procedures International (1969)	6
Soviet Scientific Reviews, Section B, Chemistry Reviews (1979) Irreg.
Sulfur Reports (1980)	6
Synlett (1989)	12
Synthesis (1969)	12
Tetrahedron (1958)	52
Topics in Current Chemistry (1949)b	Irreg.
Uspekhi Khimii (1932)	12
and its English translation: Russian chemical Reviews (1960)	12
a. See Ref. 29 b. See Ref. 30

There are several open-ended serial publications that are similar in content to the review journals but are published irregularly (seldom more often than once a year) and are hardbound. Some of these publish reviews in all fields of chemistry; some cover only organic chemistry; some specialize further. The coverage is indicated by the titles. Table A.4 shows some of the more important such publications, with CA abbreviations.

Table A.4 Irregularly Published Serial Publications.

Advances in Carbocation Chemistry

Advances in Carbohydrate Chemistry and Biochemistry

Advances in Catalysis

Advances in Cycloaddition

Advances in Free Radical Chemistry

Advances in Heterocyclic Chemistry

Advances in Metal-Organic Chemistry

Advances in Molecular Modeling

Advances in Organometallic Chemistry

Advances in Oxygenated Processes

Advances in Photochemistry

Advances in Physical Organic Chemistry

Advances in Protein Chemistry

Advances in Theoretically Interesting Molecules

Fluorine Chemistry Reviews

Fortshritte der Chemie Organischer Naturstoffe

Isotopes in Organic Chemistry

Molecular Structure and Energetics

Organic Photochemistry

Organometallic Reactions

Organic Reactions

Organic Synthesis: Theory and Applications

Progress in Heterocyclic Chemistry

Progress in Macrocyclic Chemistry

Progress in Physical Organic Chemistry

Reactive Intermediates (Plenum)

Reactive Intermediates (Wiley)

Survey of Progress in Chemistry

Topics in Physical Organometallic Chemistry

Topics in Stereochemistry

Another publication is the Index of Reviews in Organic Chemistry, complied by Lewis, Chemical Society, London, a classified listing of review articles. The first volume, published in 1971, lists reviews from ~1960 (in some cases much earlier) to ~1970 in alphabetical order of topic. Thus four reviews are listed under “Knoevenagel condensation”, five under “Inclusion compounds”, and one under “Vinyl ketones”. There is no index. A second volume (1977) covers the literature to 1976. Annual or biannual supplements appeared from 1979 until the publication was terminated in 1985. Classified lists of review articles on organometallic chemistry are found in articles by Smith and Walton³¹ and by Bruce.³² A similar list for heterocyclic chemistry is found in articles by A. Katritzky and others.³³ See also the discussion of the Index of Scientific Reviews in Appendix A.D.iv.

C.i. Annual Reviews

The review articles discussed in Table A.3 are each devoted to a narrow topic covering the work done in that area over a period of years. An annual review is a publication that covers a broad area but limits the period covered, usually to 1 or 2 years.

1. The oldest annual review publication still publishing is Annual Reports on the Progress of Chemistry, published by the Royal Society of Chemistry (formerly the chemical Society), which began in 1905 and which covers the whole field of chemistry. Since 1967 it has been divided into sections. Organic chemistry is found in Section B.

2. Because the number of papers in chemistry has become so large, the Royal Society of Chemistry publishes annual-review-type volumes of smaller scope, called Specialist Periodical Reports. Among those of interest to organic chemists are Carbohydrate Chemistry (Vol. 22 covers 1988); Photochemistry (Vol. 21 covers 1988–1989); and General and Synthetic Methods (Vol. 12 covers 1987).

3. Organic Reaction Mechanisms, published by Wiley, New York, is an annual survey that covers the latest developments in the field of mechanisms. The first volume, covering 1965, appeared in 1966.

4. There are two annual reviews devoted to progress in organic synthesis. Theilheimer, Synthetic Methods of Organic Chemistry, S. Karger, Verlag, Basel, is an annual compilation, beginning in 1946, of new methods for the synthesis of organic compounds, arranged according to a system based on bond closing and bond breaking reactions. Equations, brief procedures, yields, and literature references are given. Volume 44 was issued in 1990. Volumes 3 and 4 are available only in German, but all the rest are in English. There is an index to each volume. Cumulative indexes appear in every fifth volume. Beginning with vol. 8, each volume includes a short summary of trends in synthetic organic chemistry. A more recent series is Annual Reports in Organic Synthesis, Academic Press, New York, which has covered the literature of each year since 1970. Equations are listed with yields and references according to a fairly simple system.

C.ii. Awareness Services

Besides the annual reviews and the title and abstract services previously mentioned, there exist a number of publications designed to keep readers aware of new developments in organic chemistry or in specific areas of it.

1. Chemtracts: Organic Chemistry is a bimonthly Periodical, begun in 1988, that prints abstracts of certain recently published papers (those that the editors consider most important), with commentaries on these papers by distinguished organic chemists. Important current research in bioorganic, organometallic, synthesis, physical-organic and theoretical chemistry, and pharmaceutical/medicinal chemistry is covered in each issue, giving readers updates on the newest trends and developments in organic chemistry by summarizing and commenting on current and past research.

2. The Institute for Scientific Information (ISI), besides publishing Current Contents (sec. Appendix A.B.i) and the Science Citation Index (sec. Appendix A.B.i), also publishes Index Chemicus (formerly called Current Abstracts of Chemistry and Index Chemicus). This publication, begun in 1960 and appearing weekly, is devoted to printing structural formulas of all new compounds appearing in >100 journals, along with equations to show how they were synthesized and an author's summary of the work. Each issue contains five indexes: author, journal, biological activity, labeled compounds, and intermediates that were not isolated. These indexes are cumulated annually.

3. Theilheimer and the Annual Reports on Organic Synthesis, mentioned in the previous section, list new synthetic methods once a year. There are several publications that do this monthly. Among these are Current Chemical Reactions (begun in 1979 and published by ISI), Journal of Synthetic Methods (begun in 1975 and published by Derwent publications), and Methods in Organic Synthesis, begun in 1984 and published by the Royal Society of Chemistry. Methods in Organic Synthesis also lists books and review articles pertaining to organic synthesis.

4. Natural Product Updates, a monthly publication begun in 1987 and published by the Royal Society of Chemistry, lists recent results in the chemistry of natural products, along with structural formulas. It covers new compounds, structure determinations, new properties and total syntheses, among other topics.

C.iii. General Treatises

There are a number of large-scale multivolume treatises that cover the whole field of organic chemistry or large areas of it.

1. Rodd's Chemistry of Carbon Compounds, edited by S. Coffey, Elsevier, Amsterdam, is a treatise consisting of five main volumes, each of which contains several parts. Publication began in 1964 and is not yet complete. The organization is not greatly different from most textbooks, but the coverage is much broader and deeper. Supplements to many of the volumes have appeared. An earlier edition, called Chemistry of Carbon Compounds, edited by E.H. Rodd, was published in 10 parts from 1951 to 1962.

2. Houben–Weyl's Methoden der Organischen Chemie, Georg Thieme Verlag, Stuttgart, is a major treatise in German devoted to laboratory methods. The fourth edition, which was begun in 1952 and consists of 20 volumes, most of them in several parts, is edited by E. Muller. The series includes supplementary volumes. The first four volumes contain general laboratory methods, analytical methods, physical methods, and general chemical methods. The later volumes are devoted to the synthesis of specific types of compounds (hydrocarbons, oxygen compounds, nitrogen compounds, etc.). Beginning in 1990 parts of the series have appeared in English.

3. Comprehensive Organic Chemistry, Pergamon, Elmsford, NY, 1979, is a six-volume treatise on the synthesis and reactions of organic compounds. The first three volumes cover the various functional groups, Vol. 4, heterocyclic compounds, and Vol. 5, biological compounds (e.g., proteins, carbohydrates, and lipids). Probably the most useful volume is Vol. 6, which contains formula, subject, and author indexes, as well as indexes of reactions and reagents. The last two of these not only refer to pages within the treatise, but directly give references to review articles and original papers Several similar treatises, including the nine-volume Comprehensive Organometallic Chemistry (1982), the eight-volume Comprehensive Heterocyclic Chemistry (1984), and the six-volume Comprehensive Medicinal Chemistry (1989) are also published by Pergamon. The indexes to these works also include references.

4. A major treatise devoted to experimental methods of chemistry is Techniques of Chemistry, edited first by A. Weissberger and then by J.K.M. Saunders, Wiley, New York. This publication, which began in 1970, so far consists of 21 volumes, most of them in several parts, covering such topics as electrochemical and spectral methods, kinetic methods, photochromism, and organic solvents. Techniques of Chemistry is a successor to an earlier series, called Techniques of Organic Chemistry, which appeared in 14 volumes, some of them in more than one edition, from 1945 to 1969.

5. Comprehensive Chemical Kinetics, edited by C.H. Bamford and C.F.H. Tipper, 1969, Elsevier, Amsterdam, is a multivolume treatise covering the area of reaction kinetics. Six of these volumes (not all published at the time of writing) deal with the kinetics and mechanisms of organic reactions in a thorough and comprehensive manner.

6. Three multivolume treatises that cover specific areas are R.C. Elderfield, Heterocyclic Compounds, Wiley, New York, 1950; R.H.F. Manske and H.L. Holmes, The Alkaloids, Academic Press, New York, 1950; and J.L. Simonson, L.N. Owen, D.H.R. Barton, and W.C.J. Ross, The Terpenes, Cambridge University Press, London, 1947–1957.

7. Encyclopedia of Reagents for Organic Synthesis, edited by L. Paquette, Wiley, New York, was published in 1995. It is an 8 volume, alphabetic listing of reagents used in organic chemistry with descriptions of the preparation, use and chemistry, with references. Each reagent was researched by organic chemists active in research, who contributed to the total publication.

8. This latter work is available online as eEROS. The Encyclopedia of Reagents for Organic Synthesis, e-EROS, provides updated information on ~3800 reagents with a database of close to 50,000 reactions. Each reagent entry includes properties (e.g., physical data, solubility, form supplied in, purification, and preparative methods); examples of use in reactions; and literature references. Search options include: name, CAS number, structure and reaction.

8. Comprehensive Organic Synthesis, edited by B.M. Trost and I. Fleming, Pergamon, was published in 1991. It is a 9 volume compilation.

9. Comprehensive Organic Functional Group Transformations, edited by A.R. Katritzky, O. Meth-Cohn, and C.W. Rees, Pergamon, was published in 1995. It is a 7 volume compilation.

C.iv. Monographs and Treatises on Specific Areas

There are many books devoted to organic chemistry that provide a thorough coverage of a specific area. Many of these are essentially very long review articles, differing from ordinary review articles only in size and scope. Some are comprised of a series of articles, edited by an organic chemist for a specific area of research. Some of the books are by a single author, and others have chapters by different authors. All, however, are carefully planned to cover a specific area. Many of these books have been referred to in footnotes in appropriate places in this book. There have been several series of monographs, one of which is worth special mention: The Chemistry of Functional Groups, under the general editorship of Z. Rappoport (S. Patai was the original editor), published by Wiley, New York. Each volume deals with the preparation, reactions, and physical and chemical properties of compounds containing a given functional group. There are >130 volumes in the series, covering functional groups have appeared so far, including books on alkenes, cyano compounds, amines, carboxylic acids and esters, quinones, and so far. Since 2003, the series has appeared both in print and online.

C.v. Textbooks

There are many excellent textbooks in the field of organic chemistry. We restrict ourselves to listing only a few of those published, mostly since 1985. Some of these are first-year texts and some are advanced (advanced texts generally give references; first-year texts do not, though they may give general bibliographies, suggestions for further reading, etc.); some cover the whole field, and others cover reactions, structure, and/or mechanism only. All the books listed here are not only good textbooks and the advanced books are valuable reference books for graduate students and practicing chemists.

Bruckner, Advanced Organic Chemistry: Reaction Mechanisms, Academic Press, 2001.

Bruice, Organic Chemistry, 6th ed., Prentice-Hall, NJ, 2010.

Carey, Organic Chemistry, 8th ed., McGraw-Hill, New York, 2010.

Carey and Sundberg, Advanced Organic Chemistry: Structure and Mechanisms (Part A), 4th ed., Springer, 2004.

Carey and Sundberg, Advanced Organic Chemistry: Structure and Mechanisms (Part B), 4th ed., Springer, 2001.

Carruthers and Coldham, Some Modern Methods of Organic Synthesis, 4th ed., Cambridge University Press, Cambridge, 2004.

Ege, Organic Chemistry: Structure and Reactivity, 5th ed., D.C. Houghton Mifflin, Boston 2003.

Fox and Whitesell, Organic Chemistry, 3rd ed, Jones and Bartlett, Sudbury, MA, 2004.

Grossman The Art of Writing Reasonable Organic Reaction Mechanisms, 2nd ed, Springer, 2005.

House, Modern Synthetic Reactions, 2nd ed., W.A. Benjamin, New York, 1972.

Ingold, Structure and Mechanism in Organic Chemistry, 2nd ed., Cornell University Press, Ithaca, NY, 1969.

Isaacs, Physical Organic Chemistry, Wiley, New York, 1987.

Jones, Organic Chemistry, 4th ed. W.W. Norton, New York, 2009.

Klein, Organic Chemistry, Wiley, New York, 2011.

Loudon, Organic Chemistry, 5th ed., Oxford University Press, 2009.

Lowry and Richardson, Mechanism and Theory in Organic Chemistry, 3rd ed., Harper and Row, New York, 1987.

McMurry, Organic Chemistry, 8th ed., Brooks/Cole, Monterey CA, 2012.

Maskill, The Physical Basis of Organic Chemistry, Oxford University Press, Oxford, 1985.

Mundy, Ellerd and Favaloro, Jr. Name Reactions and Reagents in Organic Synthesis, 2nd ed, Wiley, 2005.

Ritchie, Physical Organic Chemistry, 2nd ed., Marcel Dekker, New York, 1989.

Solomons and Fryhle, Organic Chemistry, 10th ed., Wiley, New York, 2011.

Smith, Organic Synthesis, 3rd ed. Wavefunction Inc. and Elsevier, New York/London, 2010.

Smith, Organic Chemistry: An Acid–Base Approach, CRC Press, Boca Raton, FL, 2011.

Streitwieser, Heathcock and Kosower, Introductory Organic Chemistry, 4th ed., Prentice Hall, 1998.

Sykes, A Guidebook to Mechanism in Organic Chemistry, 6th ed., Longmans Scientific and Technical, Essex, 1986.

Vollhardt and Schore, Organic Chemistry, 6th ed., W.H. Freeman, New York, 2010.

Wade, Organic Chemistry, 7th ed., Prentice-Hall, Upper Saddle River, NJ, 2009.

C.vi. Other Books

In this section, we mention several books that do not fit conveniently into the previous categories. All but the last have to do with laboratory synthesis.

1. Organic Syntheses, published by Wiley, New York is a collection of procedures for the preparation of specific compounds. Organic Syntheses is currently available online.³⁴ The thin annual volumes have appeared each year since 1921. For the first 59 volumes, the procedures for each 10- (or 9-) year period are collected in cumulative volumes. Beginning with Vol. 60, the cumulative volumes cover 5-year periods. The cumulative volumes published so far are

Annual Volumes	Collective Volumes
1–9	I
10–19	II
20–29	III
30–39	IV
40–49	V
50–59	VI
60–64	VII
65–69	VIII
70–74	IX
75–80	X
81–84	XI

The advantage of the procedures in Organic Syntheses, compared with those found in original journals, is that these procedures are tested. Each preparation is carried out first by its author and then by a member of the Organic Syntheses editorial board, and only if the yield is essentially duplicated is the procedure published. While it is possible to repeat most procedures given in journals, this is not always the case. All Organic Syntheses preparations are noted in Beilstein and in CA. In order to locate a given reaction in Organic Syntheses, the reader may use the OS references given in the present volume (through OS 69); the indexes in Organic Syntheses itself; R. Shriner and R. Shriner, “Organic Syntheses Collective Volumes I, II, III, IV, V Cumulative Indices”, Wiley, New York, 1976, or S. Sugasawa and S. Nakai; “Reaction Index of Organic Syntheses”, Wiley, New York, 1967 (through OS 45). Another book classifies virtually all the reactions in Organic Syntheses (collective vols. I–VII and annual vols. 65–68) into 11 categories: annulation, rearrangement, oxidation, reduction, addition, elimination, substitution, C–C bond formation, cleavage, protection/deprotection, and miscellaneous. This is Organic Syntheses: Reaction Guide, by D. Liotta and M. Volmer, published by Wiley, New York, in 1991. Some of the categories are subdivided further, and some reactions are listed in more than one category. What is given under each entry are the equation, the volume, and page reference to Organic Syntheses.

2. Volume 1 of Reagents for Organic Synthesis, by L. Fieser and M. Fieser, Wiley, New York, 1967, is a 1457–page volume that discusses, in separate sections, some 1120 reagents and catalysts. It tells how each reagent is used in organic synthesis (with references) and, for each, tells which companies sell it, or how to prepare it, or both. The listing is alphabetical. There are now a total of 25 volumes published as of 2009, which continue the format of Vol. 1 and add more recent material. A cumulative index for Vols. 1–12, by J. Smith and M. Fieser, was published in 1990. A cumulative index for volumes 1–22 was published in 2005, by M.B. Smith. The series included volumes 1–18 with Mary Fieser.

After the death of Mary Fieser, the series was resumed by T.-L. Ho and now includes volumes 19–25.

3. Comprehensive Organic Transformations, 2nd ed. by R.C. Larock, Wiley–VCH, New York, 1999, has been frequently referred to in footnotes in Part 2 of this book. This compendium is devoted to listings of methods for the conversion of one functional group into another, and covers the literature through 1987. It is divided into nine sections covering the preparation of alkanes and arenes, alkenes, alkynes, halides, amines, ethers, alcohols and phenols, aldehydes and ketones, and nitriles, carboxylic acids and derivatives. Within each section are given many methods for synthesizing the given type of compound, arranged in a logical system. A schematic equation is given for each method, and then a list of references (without author names, to save space) for locating examples of the use of that method. When different reagents are used for the same functional group transformation, the particular reagent is shown for each reference. There is a 164 page index of group transformations. The 2nd edition has only recently been published and is not referenced in this edition, and a CD–ROM version is now available.

4. Survey of Organic Synthesis, by C.A. Buehler and D.E. Pearson, Wiley, New York, 2 vols., 1970, 1977, discusses hundreds of reactions used to prepare the principal types of organic compounds. The arrangement is by chapters, each covering a functional group (ketones, acyl halides, amines, etc.). Each reaction is thoroughly discussed and brief synthetic procedures are given. There are many references.

5. A similar publication is S. Sandler and W. Karo, Organic Functional Group Preparations, 2nd ed., 3 vols., Academic Press, New York, 1983–1989. This publication covers more functional groups than Buehler and Pearson.

6. Compendium of Organic Synthetic Methods, Wiley, New York, contains equations describing the preparation of thousands of monofunctional and difunctional compounds with references. Twelve volumes have been published so far (Vols. 1–2, edited by I.T. Harrison and S. Harrison; Vol. 3, edited by L. Hegedus and L.G. Wade, Jr.; Vol. 4–5, edited by L.G. Wade, Jr.; Vols. 6–12, edited by M.B. Smith). Volume 13 will appear in 2014.

7. The Vocabulary of Organic Chemistry, by M. Orchin, F. Kaplan, R.S. Macomber, R.M. Wilson, and H. Zimmer, Wiley, New York, 1980, presents definitions of >1000 terms used in many branches of organic chemistry, including stereochemistry, thermodynamics, wave mechanics, natural products, and fossil fuels. There are also lists of classes of organic compounds, types of mechanism, and name reactions (with mechanisms). The arrangement is topical rather than alphabetical, but there is a good index. Compendium of Chemical Terminology, by V. Gold, K.L. Loening, A.D. McNaught, and P. Sehmi (the “Gold book”), published by Blackwell Scientific Publications, Oxford, in 1987, is an official IUPAC list of definitions of terms in several areas of chemistry, including organic.

D. Literature Searching

Until recently, searching the chemical literature meant looking only at printed materials (some of which might be on microfilm or microfiche). Now, however, virtually all of the literature can be searched online. Whether the search is online or uses only the printed material, there are two basic types of search, (1) searches for information about one or more specific compounds or classes of compounds, and (2) other types of searches. First, we will discuss searches using only printed materials, and then online searching.³⁵

D.i. Literature Searching Using Printed Materials

Searching for Specific Compounds. Organic chemists often need to know if a compound has ever been prepared and if so, how, and/or they may be seeking a melting point, an ir spectrum, or some other property. Someone who wants all the information that has ever been published on any compound begins by consulting the formula indexes in Beilstein (sec. Appendix A.B.iii). At this time there are two ways to do this. (1) The formula index to the second supplement (Vol. 29, see Appen dix A.B.iii) will quickly show whether the compound is mentioned in the literature through 1929. If it is there, the searcher turns to the pages indicated, where all methods used to prepare the compound are given, as well as all physical properties, with references. Use of the page heading method described in Appendix A.B.iii will then show the locations, if any, in the third and later supplements. (2) If one has an idea what volume of Beilstein the compound is in (and the tables of contents at the front of the volumes may help), one may search the cumulative index for that volume. If not sure, one may consult several indexes. One of these two procedures will locate all compounds mentioned in the literature through 1959. If the compound is heterocyclic, it may be in the fifth supplement. If it is in Vols. 17–19 (or in a later volume whose index has been published), the corresponding indexes may be consulted. If not, the page heading method will find it, if it was reported before 1960.³⁶ There is a way by which all of the above can be avoided. At this point, the investigator will know (1) all information published through 1959 or 1979,³⁵ or (2) that the compound is not mentioned in the literature through 1959 or 1979.³⁷ In some cases, scrutiny of Beilstein will be sufficient, perhaps if only a boiling point or a refractive index is required. In other cases, especially where specific laboratory directions are needed, the investigator will have to turn to the original papers.

To carry the search to more recent articles, the chemist turned to the collective formula indexes of Chemical Abstracts and such later collective indexes as have appeared; and the semiannual indexes thereafter. However, such searches now would use SciFinder.

If the compound has not been reported, the investigator will know that. Indeed, this is perhaps the most important consideration when considering a new area of research. It should be pointed out that for common compounds (benzene, ether, acetone, etc.), trivial mentions in the literature are not indexed (so they will not be found by this procedure), only significant ones. Thus, if acetone is converted to another compound, an index entry will be found, but not if it is used as a solvent or an eluant in a common procedure.

While online searching is extraordinarily powerful, it should be pointed out that there are two problems with computer searches. First of all, far too many “hits” may be returned. For example, a 2011 research topic search (see Appendix A.D.iii) of the topic “macrolactones from hydroxy acids” gave the results:

Research Topic Candidates	References
159 references were found containing the two concepts “macrolactones”
and “hydroxy acids” closely associated with one another	159
474 references were found where the two concepts “macrolactones” and
“hydroxy acids” were present anywhere in the reference	474
35157 references were found containing the concept “macrolactones”	35157
193323 references were found containing the concept “hydroxy acids”	193323

Clearly, only examining the first few hundred references is practical. The search can, and must be refined. Depending on the scope of the search, this fact can be a limitation. The second problem relates to the search words used (the keywords). If they are too broad, little useful information is returned. If the keywords are too narrow in scope, many useful references may be missed. The point of these two cautions is to take care in choosing keywords. On the other hand, using many related keywords and doing multiple searches is very easy using SciFinder, and is probably a good strategy.

Often, all the information one needs about a compound will be found in one of the handbooks (Appendix A.C.i), in the Dictionary of Organic Compounds (Appendix A.C.i), or in one of the other compendia listed in this chapter, most of which give references to the original literature.

Other Searches. There is no definite procedure for making other literature searches using only printed materials. Any chemist who wishes to learn all that is known about the mechanism of the reaction between aldehydes and HCN, or which compounds of the general formula Ar₃CR have been prepared, or which are the best catalysts for Friedel–Crafts acylation of naphthalene derivatives with anhydrides, or where the group –C(NH₂)=N– absorbs in the IR, is dependent on ingenuity and knowledge of the literature. If a specific piece of information is needed, it may be possible to find it in one of the compendia mentioned previously. If the topic is more general, the best procedure is often to begin by consulting one or more monographs, treatises, or textbooks that will give general background information and often provide references to review articles and original papers. In many cases this is sufficient, but when a complete search is required, it is necessary to consult the CA subject and/or chemical substance indexes, and also SciFinder, where the ingenuity of the investigator is most required, for now it must be decided which words to look under. This statement relates to the keyword used for a computer search, as indicated above. If one is interested in the mechanism of the reaction between aldehydes and HCN, one might look under “aldehydes”, or “hydrogen cyanide”, or even under “acetaldehyde” or “benzaldehyde”, and so on, but then the search is likely to prove long. A better choice in this case would be “cyanohydrin”, since these are the normal products and references there would be fewer. It would be a waste of time to look under “mechanism”. In any case, many of the abstracts would not prove helpful. If it is necessary to search before 1907 (and even before 1920, since CA was not very complete from 1907 to ~1920), recourse may be made to Chemisches Zentralblatt and the abstracts in the Journal of the Chemical Society.

D.ii. Literature Searching Online²⁰

Most of the Chemical Abstracts literature can be accessed online via CAS, using SciFinder in Appendix A.D.iii, the largest and most current database of chemical substance information in the world. CAS is located in Columbus, Ohio and is a division of the American Chemical Society. CAS can be contacted at Chemical Abstracts Service, 2540 Olentangy River Road, P.O. Box 3012, Columbus, Ohio 43210 (e-mail: help@cas.org). CAS is a team of scientists who provide digital information environment for scientific research and discovery. CAS provides pathways to published research in the world's journal and patent literature back to the beginning of the 20th century. Since 1907, CAS has indexed and summarized chemistry-related articles from >40,000 scientific journals, in addition to patents, conference proceedings and other documents pertinent to chemistry, life sciences, and many other fields. Through the printed CA (Chemical Abstracts), CA on CD, STN, the CAS files distributed through licensed vendors, the SciFinder and SciFinder Scholar desktop research tools, and the STN Easy or STN on the Web services, data produced by CAS is accessible to virtually any scientific researcher worldwide in industry, governmental research institutions, and academia.

Substance identification is a special strength of CAS. It is widely known as the CAS Registry, the largest substance identification system in existence. When a chemical substance, newly encountered in the literature, is processed by CAS, its molecular structure diagram, systematic chemical name, molecular formula, and other identifying information are added to the Registry and it is assigned a unique CAS Registry Number.

The CAS REGISTRY mostly covers substances identified from the scientific literature from 1957 to the present with some classes (fluorine- and silicon-containing compounds) going back to the early 1900s. An important piece of information that assists in such a search is the CAS registry number. Each substance in REGISTRY is identified by a unique numeric identifier called a CAS Registry Number.³⁸ “The CAS Registry number is a unique number assigned to a chemical by the Chemical Abstracts Service.³⁹ A fairly large collection of CAS numbers, with links to safety data for many chemicals, can be found at the listing of chemicals by CAS number at the Safety Home Page of the Physical and Theoretical Chemistry Laboratory at Oxford University”.⁴⁰ The CAS Registry Number is a unique numeric identifier that designates only one substance, has no chemical significance, and is a link to finding information about a specific chemical substance. A CAS Registry Number includes up to 9 digits that are separated into 3 groups by hyphens. The first part of the number, starting from the left, has up to 6 digits; the second part has 2 digits. The final part consists of a single check digit.⁴¹

Online searching means using a computer terminal to search a database. Although databases in chemistry are available from several organizations, STN International (The Scientific & Technical Information Network) is important because it is comprehensive and available in many countries. STN has dozens of databases, including many that cover chemistry and chemical engineering. To access these databases a chemistry department, a library, or an individual subscribes to STN (for a nominal fee), and receives code numbers that will permit access to the system, usually via a desktop computer.

D.iii. SciFinder—the CAS database⁴²

Tutorials are available to help use Sci-Finder.⁴³ SciFinder can search a research topic⁴⁴ or a compound can be searched by structure⁴⁵ The search engine is known as STN Express with Discover!⁴⁶ and can easily and efficiently search >200 scientific and technical databases online through STN®.⁴⁷ The Analysis Edition of STN Express with Discover! allows one to search, analyze, visualize, and discover sci-tech information by the ability to create a table for substance analysis that identifies the common substructure for an answer set of structurally related substances: Group related author/inventor names and company names for better analysis and visualization results; Analyze and tabulate data from single- or multi-file search results, and create a data table and 3D chart; Save an answer set from databases (e.g., CAplusSM, PCTFULL, and USPATFULL) with the Save for STN AnaVist Wizard, and then import and open it in STN® AnaVistTM; Create an interactive spreadsheet from all or only hit CAS Registry Numbers and their corresponding CAS Roles through the CAS Registry Number®; Upload lengthy genetic sequences automatically for searching in DGENE and PCTGEN via the Upload Query Wizard. STN Express was developed in collaboration with Hampden Data Services.

To illustrate how STN is used, an online tutorial is available.⁴⁸ A few online windows from a SciFinder search are provided to illustrate how searches can be done. This presentation is by no means complete or intended as an alternative to the actual tutorial. Indeed, one could not use SciFinder properly after simply reading this discussion. The intent is to illustrate some features that are available and to present an overview of the use of this important tool.

Using SciFinder®, a search can be done in one of several different ways. Searches can be done by research topic, by substances, or by reactions. The latter two searches use drawing tools that are part of SciFinder. An example is shown of a search done by research topic:⁴⁹ The example shown in Fig. A.3. shows a search for intramolecular hydroamination of aminoalkenes. To begin, click Explore by research topic and enter the appropriate information.

It is possible to use filters (see Fig. A.1) in order to refine the search by year, document type (journal, patent, review, etc.), author or company. A window is returned that contain references categorized by their relationship to the search phrase, as shown in Fig. A.2. One simply checks those reference lists that appear closest to those of interest.

Fig. A.1 Explore by research topic.

Fig. A.2 Selection of candidates of interest for search by research topic.

After clicking on “get references,” a screen is returned (Fig. A.3) that has the original references, as shown in the window. One is given the option of refining this list further, and for each reference, most browsers allow viewing the abstract or the full references as an HTML or a PDF file. However, your library must have paid the appropriate fees so the journal and volumes of interest are available online. Otherwise, interlibrary loan or direct ordering of the article may be necessary.

Fig. A.3 Original literature references returned for search by research topic.

Other examples of typical searches allowed by SciFinder include search by author's name,⁵⁰ as with the example of Professor K. Barry Sharpless shown in Fig. A.4. Search by structure is also possible,⁵¹ such as the example shown in Fig. A.5, using SciFinder drawing tools. Once a structure is drawn, SciFinder searches to find matches based on that structure. The drawing tools can be used to show a reaction, and reaction information is returned, as shown in Fig. A.6. Ultimately, journal article and/or patents are returned that provide direct access to the literature of interest.

Fig. A.4 Screen shot for beginning a search by author.

Fig. A.5 Screen shot for beginning a search by structure, using the drawing tools.

Fig. A.6 Screen shot of results for a search by reaction, using the drawing tools.

D.iv. Science Citation Index

As seen in the SciFinder search tutorials, it is possible to track papers that have cited a particular article or author. A publication that can greatly facilitate literature searching is Science Citation Index(SCI), begun in 1961. This publication, which is quite different from any other mentioned in this chapter, gives a list of all papers in a given year that have cited a given paper, patent, or book. Its utility lies in the fact that it enables the user to search forward from a given paper or patent, rather than backward, as is usually the case. For example, suppose a chemist is familiar with a paper by W.P. Jencks and M. Gilchrist (J. Am. Chem. Soc., 1968, 90, 2622) entitled “Nonlinear Structure–Reactivity Correlations. The Reactivity of Nucleophilic Reagents toward Esters”. The chemist is easily able to begin a search for earlier papers by using references supplied in this paper and can then go further backward with the aid of references in those papers, and so on. But for obvious reasons the paper itself supplies no way to locate later papers. Science Citation Index is designed to make up for this gap. The citation index of SCI lists all papers, patents, or books cited in a given year or 2-month period (by first author only) and then gives a list of papers that have done the citing. The index is published bimonthly and cumulated annually. For example, column 43901 of the 1989 citation index shows that the Jencks paper mentioned above was cited as a footnote in 16 papers published in 1989. It is reasonable to assume that most of the papers that cited the Jencks paper were on closely related subjects. For each of the 16 papers are listed the first author, journal abbreviation, volume and page numbers, and year. In a similar manner, if one consulted SCI for all the years from 1968 to date, one would have a complete list of papers that cited that paper. One could obviously broaden the search by then consulting SCI (from 1989 on) for papers that cited these 16 papers, and so on. Papers, patents, or books listed (e.g., in the 1989 SCI) may go back many years (e.g., papers published by A. Einstein in 1905 and 1906 are included). The only requirement is that a paper published in 1989 (or late 1988) has mentioned the earlier paper in a footnote. The arrangement of cited papers or books is alphabetical by cited first author and then by cited year. Cited patents are listed in a separate table, in order of patent number, though the inventor and country are also given.

SCI covers ~3200 journals in the physical and biological sciences, as well as in medicine, agriculture, and technology. In addition to the citation index, each bimonthly and annual SCI also includes three other indexes. One of these, called Source Index, is similar to the CA author index. It lists the titles, journal abbreviations, volume, issue, page numbers, and year of all papers published by a given author during that 2-month period or year. All authors are listed; not just first authors. The second, called the Corporate Index, lists all publications that have been published from a given institution during that period, by first author. Thus, the corporate index for 1989 lists 63 papers by 45 different first authors emanating from the Department of Chemistry of Rutgers University, New Brunswick, NJ. The main section of the corporate index (the Geographic Section) lists institutions by country or (for the US) by state. There is also an Organization Section, which lists the names of institutions alphabetically, and for each gives the location, so it can be found in the geographic section. The third index included in SCI is the Permuterm⁵²Subject Index. This index alphabetically lists every significant word in the titles of all papers published in that year or bimonthly period, paired with all other significant words in the same title. Thus, for example, a title with seven significant words appears at 42 separate places in the index. Each of the seven words appears six times as the main word, each time paired with a different word as the coword. The user is then led to the Source Index, where the full reference is given. Science Citation Index is also available online (though not through STN) and on CD–ROM discs. A version of SCI that is restricted to chemistry but also includes searchable abstracts, is available only in the CD–ROM format.

The publishers of SCI also produce another publication, called Index to Scientific Reviews that appears semiannually. This publication, which began in 1974, is very similar to SCI, but confines itself to listing citations to review articles. The citations come from ~2500 journals in the same general areas as are covered by SCI. The review articles cited appeared in ~215 review journals and books, as well as in those journals that publish occasional review articles. Like SCI, the Index to Scientific Reviews contains citation, source, corporate, and Permuterm indexes. It also contains a “Research Front Specialty Index”, which classifies reviews by subject.

D.v. How to Locate Journal Articles

Having obtained a reference from various sources or searches, one often needs to consult the original journal (patents are discussed in Appendix A.A.ii). The first step is to ascertain the full name of the journal, since it is the abbreviation that is generally given. Of course, everyone should be familiar with the abbreviations of the very important journals (J. Org. Chem., Chem. Ber., etc.), but references are often found to journals whose titles are not at all familiar (e.g., K. Skogs Lantbruksakad. Tidskr. or Nauchn. Tr. Mosk. Lesotekh. Inst.). In such cases, one consults the Chemical Abstracts Service Source Index(CASSI), 1989 edition, which contains the names of all the journals covered by CA from 1907 to 1989 (even those no longer published), with the most recent abbreviations in bold print. Chemical Abstracts Service Source Index also lists journals covered by Chemisches Zentralblatt and its predecessors from 1830 to 1969, and journals cited in Beilstein before 1907. The journals are listed in alphabetical order of the abbreviations, not of the titles. Journal title changes have not been infrequent, and CASSI also contains all former names, with cross-references to the current names. Quarterly supplements, cumulated annually, to CASSI have appeared since 1990 listing new journals and recent changes in journal titles. Note that while many publications use the CA abbreviations, not all do. Usage will vary from country to country, and even from journal to journal within a country. Furthermore, the CA abbreviations have changed from time to time. This latter point is particularly important when doing keywords searches. Using a structure search in SciFinder may get around this problem.

Once the complete title is known, the journal can easily be obtained if it is in the library customarily used by the chemist, or if that journal is available in electronic form. If not, one must use another library. The next step is to find out which libraries carry the journal and CASSI answers this question too, since it carries a list of some 360 libraries in the United States and other countries. For each journal it tells which of these libraries carries it, and furthermore, if the holdings are incomplete, which volumes of that journal are carried by each library. However, most libraries have an inter-library loan service that will provide access to such journal articles. It may be possible to visit the closest library personally and CASSI also includes lists of journal publishers, sales agents, and document depositories. Photocopies of most documents cited in CA can be obtained from chemical Abstracts Document Delivery Service, Customer Services, 2540 Olentangy River Road, Columbus OH, 43210, USA. Orders for documents can be placed by mail, telephone, Telex, fax, or online through STN or other services.

These latter comments are largely out of date given the online status of most journals. As mentioned above, PDF files of an article can be downloaded, or they can be read directly via the HTML file using any current browser. The reader is encouraged to contact the library person in your establishment that is responsible for chemical literature and to learn which online services are available through your local library.

D.vi. Reaxys®⁵³

Launched in 2009, “Reaxys was created through the merger of the existing CrossFire databases (AppendixA.B.iii.) into a single database with a new and intuitive user interface. Reaxys is a fully integrated content source providing in-depth coverage of inorganic, organic, and organometallic small molecule chemistries excerpted from appropriate journal and patent literature”.⁵⁴ Reaxys is available online with drawing tools that allows entry of a structure, or multiple structures as part of a reaction. Once the structure is drawn, Reaxys offers several options for the search:

Reaxys is a unique workflow solution for research chemists providing in depth coverage of inorganic, organic, and organometallic small molecule chemistries. The database consists of chemical compounds and related factual properties; chemical reaction and synthesis information; related bibliographic data, all of which have been excerpted from a carefully selected list of journals and patents: The latter is sourced from carefully selected patent classes and patent offices. This content is delivered through a web-based interface, designed for chemists, with powerful functionality that delivers the content in a flexible and intuitive way and helps a chemist with his/her major information tasks.

At the heart of Reaxys is the concept of “Chemistry as the organizing principle”. This means that the chemical compound or reaction is central to the way in which the data is organized in the database. This is fundamentally different from bibliographic databases in which a journal or patent record is at the center. This chemically focused approach allows all data from multiple sources to be combined together in one de duplicated record for a given compound or reaction (i.e., a single compound or reaction can have multiple source citations, whereas a bibliographic database will have one record per published item, so the same compound or reaction may be found in multiple records).

The value of Reaxys to organic chemists may be understood best in relation to the synthesis of compounds, which is at the core of organic chemistry. Devising new routes to unique and artificial scaffolds requires the skills of planning and executing multistep syntheses and having a toolbox of methodologies at one's disposal. However, even the best conceived synthesis plans may require modifications, fine-tuning or entire rerouting, and chemists are faced with the daily challenge of choosing the right combination of reagents and building blocks for a whole set of problems: Which building blocks are optimal? In which sequence should they be assembled? Which reactions accomplish the task best? The Reaxys synthesis planning tool has been designed to make these choices as painless as possible using information and data from the journal and patent literature to investigate a number of possible alternative synthetic routes.

As an example, searching for papers that have reported direct arylation of indoles at the C-3 position. Construct a graphical search query (using one of the common graphical chemical structure editors, e.g., ChemDraw), with GH on indole nitrogen and also at the 5- and 6-positions of indole. The screen in Fig. A.7. shows the entry information required for the search. This query, retrieved 164 reactions from 45 citations (search results obtained in February 2012):

Fig. A.7 Search for direct arylation of indoles at C-3.

The Reaxys Version used in the above example is Application version: 1.0.9619; Content last updated: February 2012; Reactions: 31.681.788; Substances: 20.286.045; Citations: 4.504.504. Figure A.8 shows details for one of the reactions returned for this search. Also shown on this screen are various parameters that are available to search for this example. The original publication from which the reaction was taken is readily available.

Fig. A.8 One reaction returned for this search.

It is also possible to expand the literature review by viewing the details of any recent articles that cite articles of interest. This is easily achieved by clicking on the ‘view citing articles’ hyperlink. The reaction shown in Fig. A.8 was cited in the patent literature and also in the Journal of Organic Chemistry, as shown in Fig. A.9. In this manner, relevant, more recent articles may be identified and explored using citation data from Scopus. A few of such citations are shown in Fig. A.10.

Fig. A.9 Papers that cited the work in Fig. A.8.

Fig. A.10 Other potentially relevant papers based on an expanded search.

The synthesis planning tool allows a more in depth investigation. The Reaxys synthesis tool makes it easy to add more steps to the synthesis plan by searching the journal and patent literature for reactions designed to prepare the precursor molecules in any reaction step. Figure A.11 illustrates how a synthesis of a target that is consistent with the original search parameters may be constructed. Extensive property data for chemical substances is available at every stage in the process. Reaxys is a valuable addition to the information resources used by synthetic chemists.

Fig. A.11 Synthesis plan for 3-phenylindole.

Note that Reaxys and the Reaxys® trademark are owned by Elsevier Properties SA and used under license. All rights reserved.

Notes

1. See Williams, S. College Teaching 2005, 53, 137 Kennedy, M.M. Educational Researcher 2007, 36, 139; Available at www.chemistryguide.org; Gallagher, G.J.; Adams, D.L. J. Chem. Educ. 2002, 79, 1368. Also see Wolman, Y. Chemical Information, 2nd ed., Wiley, NY, 1988; Maizell, R.E. How to Find Chemical Information, 2nd ed., Wiley, NY, 1987; Mellon, M.G. Chemical Publications, 5th ed., McGraw-Hill, NY, 1982; Skolnik, H. The Literature Matrix of Chemistry, Wiley, NY, 1982; Antony, A. Guide to Basic Information Sources in Chemistry, Jeffrey Norton Publishers, NY, 1979; Bottle, R.T. Use of the Chemical Literature, Butterworth, London, 1979; Woodburn, H.M. Using the Chemical Literature, Marcel Dekker, NY, 1974. For a three-part article on the literature of organic chemistry, see Hancock, J.E.H. J. Chem. Educ. 1968, 45, 193, 260, 336.

2. For examples of the contents of an academic electronic library see http://lib.uconn.edu/ or http://www.chem.ox.ac.uk/cheminfo/ejournals.html. Also see eJournal Locator.

3. In some journals, notes are called “short communications”, an unfortunate practice, because they are not communications as that term is defined in this text.

4. In Table A.1, notes are counted as papers.

5. These journals are available in English translation.

6. These journals also publish review articles regularly.

7. Each issue of this journal is devoted to a specific topic.

8. Before 1978 this journal was called Roczniki Chemii.

9. Pure Appl. Chem. publishes IUPAC reports and lectures given at IUPAC meetings.

10. Before 1989 this journal was called Reviews of Chemical Intermediates.

11. Adobe Acrobat files.

12. Available at www.google.com/

13. See http://scientific.thomson.com/products/categories/citation/

14. Title pages of organic chemistry journals are also carried by Current Contents Life Sciences, which is a similar publication covering biochemistry and medicine.

15. Available at http://scientific.thomson.com/products/ccc/

16. For example, Chem. Ind. (London) publishes abstracts of papers that appear in other journals. In the past, journals, such as J. Am. Chem. Soc., J. Chem. Soc., and Ber. also did so.

17. For a guide to the use of CA, see Schulz, H. From CA to CAS ONLINE; VCH: NY, 1988.

18. Began in 1967. See Appendix A.B.ii.

19. These abbreviations are changed from time to time. Therefore the reader may notice inconsistencies.

20. See http://www.cas.org/expertise/cascontent/registry/regsys.html

21. An “obituary” of Zentralblatt by Weiske, C., gives its history and statistical data about its abstracts and indexes, and was published in the April 1973 issue of Chem. Ber. (pp. I–XVI).

22. For a discussion of how data are processed for inclusion in Beilstein, see Luckenbach, R.; Ecker, R.; Sunkel, J. Angew. Chem. Int. Ed. Engl. 1981, 20, 841 [Angew. Chem. 93, 876].

23. For descriptions of the Beilstein system and directions for using it, see Sunkel, J.; Hoffmann, E.; Luckenbach, R. J. Chem. Educ. 1981, 58, 982; Luckenbach, R. CHEMTECH 1979, 612. The Beilstein Institute has also published two English language guides to the system. One, available free, is How to Use Beilstein, Beilstein Institute, Frankfurt/Main, 1979. The other is by Weissbach, O. A Manual for the Use of Beilstein's Handbuch der Organischen Chemie, Springer, NY, 1976. An older work, which many students will find easier to follow, is by Huntress, E.H. A Brief Introduction to the Use of Beilstein's Handbuch der Organischen Chemie, 2nd ed., Wiley, NY, 1938.

24. In some cases, to keep the system parallel and to avoid books that are too big or too small, volumes are issued in two or more parts, and, in other cases, two volumes are bound as one.

25. Most page number entries in the combined indexes contain a letter (e.g., CHBr₂Cl 67f, II 33a, III 87d, IV, 81). These letters tell where on the page to find the compound and are useful because the names given in the index are not necessarily those used in the earlier series. The letter “a” means the compound is the first on its page, “b” is the second, and so on. No letters are given for the fourth supplement.

26. Basset, J.-M.; Copret, C.; Soulivong, D.; Taoufik, M.; Cazat, J.T. Acc. Chem. Res. 2010, 43, 323.

27. Darses, S.; Genet, J.-P. Chem. Rev. 2008, 108, 288.

28. Ding, H.; Friestad, G.K. Synthesis 2005, 2815.

29. Successor to Quarterly Reviews (abbreviated as Q. Rev., Chem. Soc.).

30. Formerly called Fortschritte der Chemischen Forschung.

31. Smith, J.D.; Walton, D.R.M. Adv. Organomet. Chem. 1975, 13, 453.

32. Bruce, M.I. Adv. Organomet. Chem. 1972, 10, 273, 1973, 11, 447, 1974, 12, 380.

33. Belen'kii, L.I. Adv. Heterocycl. Chem. 1988, 44, 269; Katritzky, A.R.; Jones, P.M. Adv. Heterocycl. Chem. 1979, 25, 303; Katritzky, A.R.; Weeds, S.M. Adv. Heterocycl. Chem. 1966, 7, 225.

34. Available at http://www.orgsyn.org/

35. For a monograph that covers both online searching and searching using printed materials, see Wiggins, G. Chemical Information Sources, McGraw-Hill, NY, 1991.

36. Compounds newly reported in the fifth supplement that are in a volume whose index has not yet been published will not be found by this procedure. To find them in Beilstein, it is necessary to know something about the system, but they may also be found by consulting SciFinder.

37. For those heterocyclic compounds that would naturally belong to a volume for which the fifth supplement has been published.

38. Available at http://www.cas.org/EO/regsys.html

39. Available at http://www.cas.org/

40. Available at http://ptcl.chem.ox.ac.uk/MSDS/glossary/casnumber.html

41. Available at http://www.cas.org/EO/checkdig.html

42. Available at http://www.cas.org/

43. Available at http://www.cas.org/SCIFINDER/SCHOLAR/interact/

44. Available at http://www.cas.org/SCIFINDER/SCHOLAR/page2a.html

45. Available at http://www.cas.org/SCIFINDER/SCHOLAR/scholstruc.html

46. Available at http://www.cas.org/ONLINE/STN/discover.html

47. Available at http://www.cas.org/stn.html

48. Available at http://www.cas.org/ONLINE/STN/expressmac.pdf

49. Available at http://www.cas.org/SCIFINDER/topic.html

50. Available at http://www.cas.org/SCIFINDER/author.html

51. Available at http://www.cas.org/SCIFINDER/structure.html

52. Registered trade name.

53. Available at https://www.reaxys.com/info/

54. Available at Reaxys_whitepaper_2011_whatsinReaxys.pdf