the chemical information instructor
Arleen SomerviUe edmd by Carlson Library University Rochester, of Rochester NY 14627
Information Sources for Organic Chemistry, 1 Arleen N. Somerville Carlson Library, University of Rochester, Rochester, NY 14627 Knowledge and understanding of the major information sources enable students and ~rofessionalchemists to find neededinformation efficientliand on a timelybasis. Learning to select the ootimum sources and use them efficientlv i s a n integral p& of chemical literacy. This article provides ready-to-use lecture material about organic chemistry information sources, a chart that links sources with questions that is suitable for distribution to students, and a set of practice questions. Organic chemists have information questions characteristic of their research. These questions generally fall into : reeither of two. occasionallv overlaodn~. .- e r o u.~ s those lated to the synthesis or pieparationof substances, orthose related to mechanistic or ohvsical oreanic chemistry. The former group might include name readions, reactiontypes, functional group transformations, solvents and reagents, synthesis or reactions of a class of compounds or specific compounds, and preparative techniques. Questions in the second group might include problems involvingthe relation of structure to kinetics or equilibria, the structure of molecules or transition states, types of reaction mechanisms, and spectroswpic aspects of organic chemistry Some questions, such as those about stereochemistry, may arise under either of the two groups, depending on the context or major thrust of the query. This, and succeeding columns, will offer a chart that lists these categories of organic chemistry questions and suggests some optimum or typical sources. The reader should be aware that such source lists are necessarily representative rather than exhaustive, that certain sources may be relevant to more than one question category, and that some degree of judgment or prioritization must be exercised in the use ofthese lists. While the list of sources is not meant to be comprehensive, this chart helps develop efficient searching skills and chemical information literacy. The full list is suitable for use with upper level undergraduates, graduate students, and professional chemists. For other undergraduates, the instructor will want to include selective sources relevant to their information questions. I n using this chart, chemists should identify the various ways that their questions can best be answered using the tabulated categories as guides. One could thus ask about a synthesis question: Is a specific functional group transformation involved? Would the use of a name reaction be helpful? Is a general type of reaction likely to be required? What reagent would be best? Has a similar substance been synthesized? From such an analysis one can proceed to the chart to determine which sources to examine first. In certain cases more than one category should be consulted. For example, for a functional group interconversion, one can start a search under functional transformations, but one might supplement this search using sources listed under
reaction type or possibly under class ofcompounds. Specific features of many sources are described and illustrated here, so that the information can be used for lectures. Complete hihliographic information is provided in an alphabetic list at the end of the article. This article covers sources for name reactions and reaction types; future articles will describe sources for other categories. Searching by Name Reaction Classic reactions of broad scope may be named aRer the diswverers or developers of the reactions. These "name" reactions are importanttools oforganic chemists. Achemist may ask: What is the ester enolateversion of the Claisen rearrangement? Has a recent article described use of the intramolecular Wittig reaction ? Can one find an example of the Carey-Kim oxidation? Certain sources answer questions about such name reactions Name Reaction: General Sources
1.Mundy. Name Reactions and Reagents in Organic Chemistry. An excellent, concise, easy to scan reference source. The bookis dividedintotwomain sections:name reactions, and reagents used in name reactions. For each name reaction, two pages provide the care information. Figures l and 2 show the two pages far the Claisen rearrangement. Figure 1provides a textbook reference for ageneral description of the Claisen rearranEement, the general reaction scheme. the reaction mechanism, notes that augment the reaction scheme or mechanism or that amplify examples on the fallowing page designated with a triangle, and selected major references keyed to examples on the following page. Figure 2 lists five examples of the Claisen rearrangement, usingreaction diagrams. The circled numbers link the examples to the references on the previous page. 2. March. Advanced Organic Chemistry A reference sourcefor students and professional chemists. Part 1covers information to help students understand mechanisms including chemical bonding, stereochemistry, and the effects of structure on reactivity. Part 2 is organized by reaction types, with chapters on aromatic nucleophilic and electrophilic substitution, aliphatic nucleophili~and eleetrophilie substitution, free-radical substitution, eliminations, rearrangements, oxidations,reductions, additions to carbonVolume 68 Number 7 July 1991
553
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4. E.J. carny, n . ~ ,bfispr. s. chananrpkm-. 0-. a. Am. Cba. Sac.. (18781, iW. 8031. I.E.D. Burke -d
O.J. P.rnhkY,
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sirrt, c . e neck, nnd 2.-L.
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Figure 1. First of two pages on the Claisen rearrangement from Mundv. Name Reactions and Reagents in Organic Chemistry. (Reproduced with permission of ~ i ~ e y j carbon multiple bonds, and additions to carbon-hetero multiple bonds. Discusses scope, limitations, and mechanisms, and provides extensive references to journal articles for detailed experimental procedures. Includes a detailed subject index that permits rapid location of such name reactions a s Cope rearrangement, Dieckmann condensation, or Vilsmeier readion.
3. Carey a n d Sundberg. Advanced Organic Chemistry
Part B. A comprehensive textbook for advanced undergraduates and graduate students, which professional chemists will use as a reference manual. Describes synthetically useful reactions and their applications in an easy-to-folloiv format using extensive reaction diagrams, with references to journal articles and handbooks. Provides an excellent description of such name reactions as Wittig, Diels-Alder, Claisenrearrangement, Birch reduction, and Cope rearrangement, all of which can be found in the index. Many reaction mechanisms are given. Each chapter concludes with a selected list ofgeneral references and practice questions. 4. Surrey. Name Reactions in Organic Chemistry One of several books that offer brief definitions of name reactions. Provides brief two . oape - summaries of over 130 name reactions of general interest. References refer ta journal articles and book chapters for more details.
554
Journal of Chemical Education
Figure 2. Second page on the Claisen rearrangement from Mundy. Name Reactions and Reagents in Organic Chemistry. (Reproduced with permission of Wiley.)
5 . Organic Reactions Published approximately once per year since 1942. Contains extensive review chapters, each covering a single reaction of wide application. Chapters cover: reaction mechanism scope and limitations of the reaction experimental conditions experimental techniques related synthetic processes several detailed experimental procedures that illustrate the reaction. These procedures, unlike those in Organic Syntheses, have not been checked in two laboratories. tables listingall examples ofthereaction with comprehensive list of references to original journal articles Tolocate relevant chapters, check the cumulative subject index in themost recent volume. Far example, the index farvolumes 1-39 is found a t the back of volume 39. The 420-page Vol. 112. 1990 - GENERAL SUBJECT INDEX
of phosphoranylidenepropyl arnides, 2166079 of s v i r a l i s o a u i n o l i n e vhosvhonate d e r i v . ,
intramol. cyclacondensation r e a c t i o n and, of acetvlhvdroxvxanthone with
Figure 3. Intramolecular Wittig reaction found in CA General Subject Index, v. 112. (Reproduced with permission of American Chemical Society.)
Beckmann Reactions chapter in volume 35 is found quickly in the Index. Caution: Be cautious about using reactions given in the old volumes.Although somereactiansareclassics,othersarenow obsolete.
6. Chemical Abstracts (CA) A. A limited number of major, classic name reactions, such as
Wittig, Claisen rearrangement, Diels-Alder, and Grignard reactions, can be found in the General Subject Index or by a computer search of CA. 1.A search for articles on use of the intramolecular Wittig reaction is illustrated in Figure 3. A check in the General Subject Index of v. 112 (Jan.- June 1990) under "Wittig reaction, intramolecular" 1-tes about four references. To identify the first article, check the abstract number 2O83lf in v. 112. Figure 4 showsthe article title, the author and his affiliation, the abbreviated journal title, publication year, volume and issue number, pages, language, and brief summary of article.
I Figure 5. Computer search of CA for 1990 articles on intramolecul~ Wittig reaction. (Reproduced with permission of American Chemic Society.)
II
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L1 ANSWER 2 OF U COPYRIGHT(01991AMERICAN CHEMICAL SOCIETY CA114(7):6165Zh Anovel synthesis of ponunoalkylated al~ha,.beta-unsatlvafed carbony1mmmunds. Shen. Yanchana wing. Tielin (Shanghai lnsL o&. ~ h e i . .Acad. Sin.. shanghaiUKK)32,Pmp. Rep. China). Tetrahedmn Len, 31(41).59256 (F.ng) 1990. CODEN. TEIEAY. ISSN: CC404039.
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Figure 6. One article about the intramolecular Wittig reaction found bv comnuter search of CA. lReoroduced with ~ermissionof American ~hehemidalSociety.) =>
s (corey kim)/bi,ab 121 COREYIBI 41 KlMlBl 4 (COREY KIMVBI
obtain4 by rtacthn of
aCcW3
11 uiB mP+C.:CO and
inmmol. 456 KIMIAB 3 (COREY KIM)/AB
L2
Figure 4. CA abstract information for article found in Index. (Reproduced with permission of American Chemical Society.) 2. Or, one can mnduct a computer search of CA. (CA File on STN International was used.) A search of 1990 CA for articles about the intramolecular Wittig reaction is shown in Fieure - 5. A comouter search not only matehes Wittigreactionas a General Subject Indexheading, but also when it aooears in the article title. kevwords. and modiFiing Note the use of of the Chemical ~ u b s t a n i index: s (L) to search for intramolecular specifically related to Wmlgreactmnand the t~~lnestmn symbol P I to search for the abhrevlatrd and full forms of ~ntrdmolecularOne of the 27 answers is shown in Figure 6 B. Other name reactions are considerably more diff~cultto find in CA. A comouter search of CA, with increased access to words and terms within the article title, keywords, subject and substance indedng, and abstracts, may locate some relevant articles that use name reactions. Such a search is not comprehensive, because We name of the name reaction may not appear in the article title, indexing or abstract.
((COREY(W)KIM)/AB) 5 (COREY KIM)/BI,AB
Figure 7. Computer search of CA for Corey-Kim reaction. (Reproduced with permission of American Chemical Society.) -
=;OF5 COPYRIGHT(C) 1991 AMERICAN CHEMlCALSOClETY
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CA112(11):9mz Convenient tyntheoio of sulfur ylidea by reaction ol actwe melhviene mmmvnds with corev-~imreaaent. Kalavama.
L2 ANSWER 2 OF5 COPVRiGHT (C) 1991 AMERICAN CHEMICALSWETY
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CASREACT 110:23451
Figure 8. Two of the references about the Corey-Kim reaction found by computer search of CA. (Reproducedwith permission of American Chemical Society.)
The computer search for articles about use of the Carey-Kim
reaction should specify that the abstract and all parts of the Basic Index(B1)(article title, keywords, andindexing) should besearched. Two ofthe fivearticles foundare shown in Figure 8.
Name Reaction: Specific Sources Some name reactions a r e sufficiently important t h a t books a r e published about them. These sources provide
extensive information about the reaction and often include comprehensive lists ofrelevant references. These books can he identified by searching computerized versions of CA for the name of t h e r ~ a c t i o ~ a nkmblning d it with the word BOOK. Also. comouterized libraw catdoas can he accessed by keywords, which would iden&cation of books when t h e name reaction is part of the book title. Four examples a r e listed here: Volume 68
Number 7
July 1991
555
The chapter on synthesis of alkenes has sections on their
7. Kharasch. Grignard Reactions of Nonmetallic Sub-
meparation bv isamerization, elimination, alkvlidenation of . . rarbnnyi compounds, metal-promoted coupling rmetinns, ecc. To locate information on prepmatron ofalkenes by elimination reactions, check the de&il;d table of contents i f the Alkenes chapter under "Elimination". Mare than 50 specific types of elimination reactions, often based on different functional group transformations, are listed. Onecanreadilyidentifythe relevant pages hy selecting the type of elimination reaction required by the experiment. For example, if one's reaction involves amine oxides, the information in Figure 9 would be relevant. The reaction scheme is shown, along with three majorrefereneesto Journal ofthe American ChemicalSociety, Organic Reactions and Organic Syntheses.
stances
8. Fringelli a n d Taticchi. Dienes i n the Diels-Alder Reaction
9. Olah. Friedel-Crafts and Related Reactions
10. Robinson. Fischer Indole Synthesis Searching by Reaction Type Another group of questions asked b y organic chemists involve types of reactions. They m a y ask: How does one carry out the halomethylation of an ammatic ring? or What is the best way to carry out the reductive elimination of heta-haloesters, and what is the reaction stereoehemistry? Certain reference handbooks a n d books answer these questions very well.
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9. Arnlne Oxlda (Cope Ellmlnatlon)
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Reaction Type: General Sources
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11.House. Modern Synthetic Reactions Written for advanced undergraduates and beginning graduate students. Arather detailed survey of many important synthetic methods commonly used. An essential reference book for all new synthetic chemists. Examples of chapters: Metal hydride reduction, oxidation, halogenation, alkylation, aldol condensation, acylation. However, some important reactions, such a s the Diels-Alder reaction and Claisen rearrangement are not discussed; instead, readers are referred to other sources. Information provided: reaction mechanism, stereochemistry, reaction conditions, examples of the reaction. For detailed experimental procedures, readers are referred to journal articles and nth& handbooks. Multiple references to the same reaetion are usually provided. An extensive subject index provides quick access to information. for example, on acylation of esters, hromination of earbox& acids, & hydrob&ation of enamines
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3. Laroek. Comprehensiue Organic Transformations Although the primary organization is by functional groups being synthesized, each section is subdivided by major reaction types, such as reduction, oxidation, alkylation, suhstitution, elimination, coupling, halogenation, isomerization, etc. In some ways, this is an updatedversion of Wagner and Zook, Synthetic Organic Chemistry. Focus is on major preparative reactions that are general in scope and on literature references in primary journals. It is not exhaustive and specialized reactions are often not included. Review articles are aRen listed a t the beginning of sections, such as under Dehydrogenation of Alkenes. 558
Journal of Chemical Education
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IACS 81 2799 t1959). 1011 1039i1986) 00 Ru 11 361 (l%Oj(rcnm) 0 % Sya Coll Vol d 612 11%31
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I I Figure 9. Entry from Larock. Comprehensive Organic Transfofma-
14. Fieser. Reagents for Organic Synthesis The long-time premier source for information about reagents. The first and most extensive volume was published in 1967. Thirteen volumes have appeared since then in this continuing series. Entries list reaction scheme, along with brief, concise comments about preferred methods of preparation. References are given for journal articles that provide necessary experimental details. Each volume includes an index ofreagents accordingto reaction type. A check under "Oxidation, Reagents" lists all oxidation reagents discussed in that volume. Anew Collective Index forvolumes 1-12 (1990) includes a more detailed '"Type of Reaction Index" that permits precise selection of reagent. To find information on "Oxidation Reactions", scan the twelve pages devoted to this topic far the specifictype of oxidation reaction needed. For example, the subheading ALCOHOLS RCHO, RzCO lists two pages of reagents. One can easily locate the chromium reagents group and select the entry for "Potassium chromate, 9, 357". The entry on p. 357 of volume 9 is shown in Figure 10. Reference 13 refers to iournalarticle hvD. Landini. F. Montanan'andF. Rolla which was published in Synthesis, p. 134 (1979).
12. C a n u t h e r s . Some Modern Methods of Organic Synthesis Aimed at advanced undergraduates and beginning graduate students. Updates and complements House (no. 11); covers many reactions not included in House, hut in less detail. Provides the most important features of reactions. Chapters cover: formation of earbon+arbon single bonds and double bonds, synthetic applications of organohoranes and organosilanes, oxidation and reduction, reactions a t unactivated C-H bonds, and the Diels-Alder and related reactions. Information such as oxidation of alcohols or catalytic hydrogenation canbe found readilyin the rather detailed subject index.
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I odd*rla. of.1~hoI1.I' primary and secondsry almhole can be oxidized to aldehydes and kctoner, respc~ivdy,by potassium chromate and sulfuric acid i n s two-phase ryslcm (CHC1,-40) in the presence of tetra-n-butylammoniumhydrogen sulbtc sr catalyst. ~ h method c is particularly useful for oxidation of ~rirnrry
IGH.I.PHID~
c*c~,.",o"
IROIzOH+2K2Cr04+SH2S01
~RCHO+~K.SOI+C~.~SO.IS+~HHO
alrohak. since sldehvdea are not oxidized further lo r%rborvlicacids vndsr thew
Figure 10. Entry from Fieser, Reagents for Organic Synthesis, v. 9 (Reproduced with permission of Wiley)
15. Organic Reactions Mentioned also as a source far name reactions (see no. 5 above) Contains extensive review chapters which cover: 'reaction mechanism scope and limitations of the reaction experimental conditions and techniques related synthetic processes several detailed experimental procedures that illustrate the reaction 'tables listing all examples of the reaction with a wmprehensive list of references to the original journal articles To locate relevant chapters, cheek thecumulative subject index in themostrecentvolume. For example, theindex for volumes 1 9 9 is found a t the hack of volume 39. A chapter on rearrangement of vinyleycloprnpane to cyclopentene is found in volume 33, chapter 2 by looking under Rearrangement. This 90-page article includes a wmprehensive table that lists starting materials, products and yields, reaction conditions, and refers to the 228-article bibliography.
16. Organic Syntheses Published annually since 1921. Gives proven procedures for the synthesis of individual organic compounds. Each synthesis has been checked and reproduced in a second laboratory before publication. Provides full experimental details of each synthesis. Collective volumes are available that revise and update the information published in the annual volumes: v. 1-9 revised a s Collective Volume l(1932) v. 1lL19 revised a s Collective Volume 2 (1943) v. 2lL29 revised as Collective Volume 3 (1955) v. 3lL39 revised a s Collective Volume 4 (1963) v. 4&49 revised a s Collective Volume 5 (1973) Separate volume of Cumulative Indices far Collective Volumes 1-5 v. 5&59 revised a s Collective Volume 6 (1988) v. 6&64 revised as Collective Volume 7 (1990) The Concordance Index that appears in the last several CollectiveIndexVolumeslists the annualvolume and page number where each procedure first appeared. This correlation is important because bibliographic references often refer to annual volumes, whereas the Collective Volume preparations are updated and therefore preferred. Locating a desired procedure by reaction type can be accomplished in two ways: 1. Check the "Type of Reaction Index" in the most recent volumes and work hack in time. This index has become quite detailedinrecent volumes, which is helpful for highly specific questions. Begin with the most recent index in the annual volumes (i.e., v. 68 that includes a n index far volumes 65-68), followed by the Collective Volume 7, then 6 and back a s far a s appropriate. To find recent references to preparation of cyclobutanone by oxidation of an alcohol, check the "Oxidation" entry in the "Type of Reaction Index" in Collective Volume 7. One of the choices is shown in Figure 11. Selection of the cyclobutanone entry leads to the four-
IA I A
IAb, A
CHOH
C=O
[Hn02/Cl 3-Butyroyl-l-methylpyrrole, 102 [CrOJH,C,o,] [CrO,]
Cyclobutanone, 114
3,3-Dimethyl-cis-bicy-
c l o [3.2.0]heptan-2-one,
177
[(COC1J2/DMS01 G e r a n i a l , 258
Figure 11. Entry from Organic Syntheses, Type ot Reaction Index (Reproduced with permission of Wiley) page experimental details of its preparation, along with comments on its uses. A 22-article bibliography leads to related procedures. 2. A Reaction Guide, published in 1991, summarizes in structural format all procedures published in volumes 148. Procedures are organized by 11hmad classes of reaction types, which, together with the highly visual structure format, permit rapid scanning of reaction categories. Theeleven classes include: addition, annulation, C-C bond formation, cleavage, elimination, oxidation, pmtectiod deprotection, rearrangement, reduction, substitution, and miscellaneous. To use, check the Table of Contents for "Oxidation". Six hmad categories of oxidation reactions are listed: heteroatom, epoxidation, halogenation, chromium reagents, manganese reagents, and general. The 10 pages of chromium reagent entries are arranged chronologically by Collective Volume numbers. The pages can he scanned quickly ta find the same synthesis as in the "Type of Reaction Index" above. The reaction scheme as shown in Figure 12 focuses on the reactian site, which facilitates generic hrowsing. For full experimental details, one is referred to Organic Syntheses Collective Volume 7 p. 114 and Organic syntheses Volume 60 p. 20.
Figure 12. Entry from Organic Syntheses, Reaction Guide (Reproduced with permission of Wiley.)
. . . . . . . . ~~ a l m t h y l m i a nof Advatad Carbon Ammr. . . . . . . . . . . nalmmhylatian of Ammatic Campound%. . . . . . . . . . . . Halmwhylation of Orpanic Gmvounds
Halmthylalion of AOlI Halidas
. . . . . . . . . . . . . . .
Figure 13. Tabie-of-contents from Mathieu, Formation of G C Bonds, v.1, showing core reaction schemes. (Reproduced with permission of Thieme.)
Volume 68
Number 7
July 1991
557
IA
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1 Ab,
A,-n
Halomahylation
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nr-cn2x
Halomethylation of A r o m a t i c C o m p o u n d s Since 1898, halomethylation of aromatic wmpounds has been the subject of a number of investigations, in panicular owing to the high reactivity of halogens which facililatessynthesasof numerousderivmives'-
