AWARDS
ACS 1994 Award Winners ollowing are vignettes of the Arthur C. Cope Award winner and 10 recipients of Arthur C. Cope Scholar Awards. They will receive their awards at the annual Arthur C. Cope Symposium organized by the ACS Division of Organic Chemistry. The symposium will be held in Washington, D.C., during the ACS national meeting Aug. 21-26,1994. These awards recognize and encourage excellence in organic chemistry. The Cope Award consists of a medal, a personal cash prize, and an unrestricted research grant to be assigned by the recipient to any university or nonprofit institution. The scholar awards consist of a certificate and an unrestricted research grant. Each recipient is required to deliver a lecture at the Arthur C. Cope Symposium.
dergraduates and beginning graduate students. Roberts has received myriad awards, including the 1987 Priestley Medal, the American Chemical Society Award in Pure Chemistry, the Roger Adams Award, the Linus Pauling Award, and the Robert A. Welch Award. In 1990 he was awarded the National Medal of Science. He is a member of ACS, the American Philosophical Society, and the National Academy of Sciences.
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Arthur C. Cope Award JOHN D. ROBERTAS contributions to chemistry during his more than 50 years in the profession extend far beyond the new knowledge generated by his research. His accomplishments have profoundly influenced how chemists think about, approach, and teach chemistry. Roberts' work helped shape physical organic chemistry. He was one of the first to use the tools of physical chemistry—quantum mechanics, molecular spectroscopy, kinetics, and other techniques—to solve problems in organic chemistry. "If the idea that organic chemistry and physical chemistry share a common border now seems selfevident, it is in major part because Roberts demonstrated the utility of research techniques drawn from the latter in solving problems of the former," writes one of his colleagues. For example, Roberts played a role in developing hydrogen-1, carbon-13, nitrogen-15, and fluorine-19 nuclear magnetic resonance (NMR) spectroscopies as organic chemistry techniques. He used NMR to probe the structure and reactivity of molecules, including nitrogeninversion, rotation about carbon-nitrogen bonds, rotational isomerism about 46
NOVEMBER 8,1993 C&EN
Arthur C. Cope Scholar Awards Roberts
single bonds, conformational equilibration and conformational analysis, and enzyme structures. Roberts pioneered the use of isotopic labeling to trace molecular rearrangements. He also introduced organic chemists to the use of molecular-orbital theory for exploring the structure and reactions of organic molecules. And he defined methods of determining structures of reactive intermediates, such as nonclassical cations—a term he coined— and benzyne. Roberts received both B.A. (1941) and Ph.D. (1944) degrees in chemistry from the University of California, Los Angeles. After a postdoctoral stint at Harvard University, he joined the faculty of Massachusetts Institute of Technology. He moved to California Institute of Technology's division of chemistry and chemical engineering in 1953, where he has remained ever since. He has served as Caltech's vice president, provost, and dean of the faculty. As emeritus Institute Professor of Chemistry since 1988, Roberts has continued his NMR studies with undergraduate research students, five of whom worked in his lab this past summer. "Undergraduate research in chemistry changed the course of my life," he says. "Now I'm trying to do what I can to help someone else." He also teaches a course and is writing a book on intermediate NMR concepts for advanced un-
MAURICE S. BROOKHART's research is at the frontier of mechanism, structure, bonding, and reactivity in organometallic chemistry. Particularly noteworthy are his contributions in agostic bonding and alkene polymerization, and in alkylidene complexes and enantioselective cyclopropanation. Brookhart is William R. Kenan Jr. Professor of Chemistry at the University of North Carolina. Early in his career, Brookhart carried out some of the first systematic investigations of valence isomerism of cyclic polyene ligands. He observed that the less stable of two valence isomers is often more reactive toward a metal fragment, enabling the preparation of previously inaccessible organic compounds. Further research on these compounds led to his discovery in 1977 that certain iron alkylidene complexes were isolable. Brookhart developed efficient methods for preparing a variety of these complexes in optically active form. These alkylidene complexes have proved to be excellent cyclopropanating agents. Perhaps the award winner's most significant contribution has been his study of carbon-hydrogen-transition metal bonds. He systematized scattered literature data that indicated widely prevalent, but generally unrecognized, chelate-type three-center, two-electron carbon-hydrogen-metal bonds. This nonclassical bonding—termed agostic by Malcolm Green, professor of chemistry
at Oxford University, and Brookhart during his sabbatical at Oxford—plays a key role in carbon-hydrogen activation reactions, alkene polymerizations, and many other processes. Brookhart first noticed agostic bonding while investigating hydrogen migrations in metal tricarbonyl complexes of cyclohexadienes. He verified this bonding in the solid state with a neutron diffraction study. In more recent research, Brookhart discovered a new catalytic reaction involving an agostic rhodium complex— the tail-to-tail dimerization of methyl acrylate to unsaturated adipic acid esters that can be converted to adipic acid, one of the monomers used in nylon 6,6 production. This accomplishment, points out a colleague, "places Brookhart among the very few individuals able to successfully design new metal-catalyzed transformations—probably the foremost challenge in organometallic chemistry today/7 Brookhart obtained a B.A. degree in chemistry from Johns Hopkins University in 1964 and a Ph.D. degree in physical organic chemistry from the University of California, Los Angeles, in 1968. Following two stints as a postdoctoral fellow, he joined the faculty at the University of North Carolina as assistant professor in 1969. Brookhart received the 1992 ACS Award in Organometallic Chemistry. He served as chairman of the organometallics subdivision of the ACS Division of Inorganic Chemistry in 1987, and as chairman of the Gordon Conference on Organometallic Chemistry in 1986. He is currently serving as associate editor of Organometallics. Exactly the kind of scientific scholar that the Cope Scholar Awards were designed for, is the way one colleague views PAUL DOWD. Another regards him as among the top half-dozen American chemists in physical mechanistic organic chemisty in originality and impact. Dowd has a lengthy string of outstanding research achievements. He discovered the first non-Kekule diradical— trimethylenemethane—using electronspin resonance spectroscopy. Prior to this, scientists believed that the 1,3diradicals could never be observed because they would escape by ring-closure to their cyclopropane counterparts before they could be detected. This finding
Brookhart
Dowd
Foote
by Dowd, who is professor of chemistry tional Science Foundation fellow (1962), at the University of Pittsburgh, opened Alfred P. Sloan Foundation fellow (1970-72), fellow of the American Assoan entirely new field. The award winner contributed to an ciation for the Advancement of Science understanding of the mechanism of ac- (1987), and Chancellor's Distinguished tion of vitamin B12 with the isolation of a Research Award, University of Pittscarbon-skeleton rearrangement product burgh (1993). He is chairman-elect of the for the first time in the absence of en- 1995 Gordon Research Conference on zyme. As a result, these enzymatic pro- Physical Organic Chemistry. cesses can now be studied as organic reactions. More recently, Dowd came up "Mister Singlet Oxygen" is how a colwith the first model for the coenzyme league describes CHRISTOPHER S. B12-dependent methylmalonyl-CoA re- FOOTE, professor of chemistry and arrangement that incorporates both hy- biochemistry, University of California, drogen abstraction and rearrangement Los Angeles, for his work in developin the same model. ing the organic chemistry of singlet In studies of new synthetic routes to oxygen. In the mid-1960s, Foote showed that medium-sized rings, Dowd has developed several new approaches. These the reactive intermediate in sensitized are based on generating a free radical photochemical oxidations is electroniintermediate appropriately placed next cally excited singlet molecular oxygen, to a carbonyl group. The most recent formed by energy transfer from an exresult of this work is a high-yield free cited sensitizer to ground-state oxygen. radical method for bridging a 1,5-diene That discovery led to an explosion of interest in singlet oxygen, which subsewith the elements of ketene. Dowd's current most notable achieve- quently was found in systems as diment is his proposal for the mechanism verse as polluted air and metabolizing of action of the blood-clotting vitamin, liver cells, and opened up new research vitamin K. He and his coworkers theo- fields for polymer and environmental rize that the formation of vitamin K ox- chemists, biologists, biophysicists, and ide drives the carbon-carbon bond-form- physicians, among others. ing carboxylation. The oxidation to vitaFoote's group has achieved a string of min K oxide produces 58 kcal per mole discoveries, some with important practiand this energy is used to generate the cal consequences. The group was the base strength needed to drive the con- first to show that (3-carotene quenches densation with carbon dioxide. Thus, the singlet oxygen to harmless ground-state key to the mechanism is a controlled oxygen at a very high rate, using an encombustion reaction. ergy transfer mechanism. The team sugDowd received an A.B. degree from gested this as the mechanism by which Harvard University in 1958 and a Ph.D. carotenoids protect plants from being degree in chemistry from Columbia Uni- damaged by their own photosynthesis. versity in 1962. After one year as a re- p-Carotene has been used as a treatment search fellow at Harvard under Robert for patients with a type of porphyria that B. Woodward, he joined the faculty as lec- causes them to be sensitive to light. This turer. He joined the University of Pitts- work also led to the development of agents that protect foods from unwanted burgh in 1970 as an associate professor. Among his numerous honors are Na- photooxidation. NOVEMBER 8,1993 C&EN
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AWARDS Foote and his coworkers have played a major role in establishing the mechanisms by which singlet oxygen reacts with dienes, alkenes, and sulfides. They have shown conclusively that many of the reactions involve intermediates, such as the trappable zwitterionic species responsible for the isomerization of the dienes in the diene reaction. Foote and his team were among the first to detect the weak luminescence at 1.27|i from singlet oxygen and use it for mechanistic studies, such as the production of singlet oxygen from the fullerenes. They were the first to detect the triplet states of C60 and C70, measure the energy of these states, and describe how the energy is transferred to oxygen. They were the first to show that triplet C60 is a strong oxidant and to produce the C60 radical cation by photochemical electron transfer. Foote's group has studied the reactions of singlet oxygen with biological target molecules such as vitamin C and vitamin E. The team has used chemical probes to identify reactive intermediates—such as singlet oxygen and hypochlorous acid—of the antimicrobial action of human white blood cells that produces a powerful chlorinating agent. This work is leading to the development of specific chemical probes for identifying reactive chemical intermediates in complex living systems. Foote received a B.S. degree from Yale University (1957) and a Ph.D. degree from Harvard University (1961). He was a Fulbright fellow at the University of Gottingen (1957-58) and held A. P. Sloan (1965-67) and J. S. Guggenheim (196768) fellowships, among others. His awards include the Yale Science & Engineering Award for Advancement of Basic & Applied Science (1975) and the Leo Hendrick Baekeland Medal of the American Chemical Society (North Jersey Section, 1975). He has more than 180 scientific publications to his credit. "ERIC N. JACOBSEN is an emerging leader in organic chemistry of exceptional promise and accomplishment/' writes a colleague. Jacobsen is now professor of chemistry at Harvard University, but during his nearly five years on the faculty of the University of Illinois, UrbanaChampaign, he initiated a broad program in the area of catalytic asymmetric synthesis, involving methods for oxidation of olefins and sulfides, cyclopropanation, aziridination, conjugate addi48
NOVEMBER 8,1993 C&EN
tion, aldol condensation, and remote functionalization. Jacobsen has already succeeded in developing a catalyst for asymmetric epoxidation of simple olefins, a breakthrough that had eluded the efforts of major research groups around the world. Jacobsen's epoxidation reaction is widely recognized as an outstanding accomplishment. In his initial work on this reaction, Jacobsen found that manganese complexes of chiral Schiff bases catalyze the highly enantioselective oxidation of unfunctionalized alkenes. Earlier workers had succeeded only in achieving high selectivities in epoxidation of alkenes that had additional functional groups, which placed their transformations under severe restriction. The complexes that Jacobsen has prepared are simple to synthesize and are efficient catalysts for performing these oxidations in high yield, with high catalytic efficiency, and with high asymmetric induction. In addition, Jacobsen has elucidated fundamentally important mechanistic knowledge about asymmetric oxidation from this reaction. In particular, he can rationalize, predict, and even control the sense and degree of asymmetry he will observe in these oxidations, as he varies the structure and electronic characteristics of the oxidation catalyst and the organic reactant. Furthermore, he has illustrated the practical utility of this new reaction by applying it to the synthesis of several biologically important molecules. Jacobsen has been honored with a Presidential Young Investigator Award, a Lilly Fellowship, a Packard Foundation Award, a Camille & Henry Dreyfus Teacher-Scholar Award, a Sloan Foundation Fellowship, the Cyanamid Young Faculty Award, and the Pfizer Young Faculty Award for Synthetic Organic Chemistry. He received a B.S. degree in 1982 from New York University and a Ph.D. degree in 1986 from the University of California, Berkeley. MARTIN NEWCOMB, professor of chemistry at Wayne State University, Detroit, has studied rate constants and reaction mechanisms for radical processes that have important consequences for topical problems. Recognized internationally as a careful and thorough investigator, his work is at the forefront of modern physical organic chemistry. His research unrav-
eled the complex problem associated with mechanistic studies using alkyl halide probes and led to new kinetic methods to measure exceedingly fast radical reactions. Radical rearrangements have been extensively used as probe reactions to detect free-radical intermediates. During the late 1970s and early 1980s, studies reporting that alkyl halides reacted with various nucleophiles to give products formed by radical cyclization led chemists to believe that single electron transfer (SET) reactions of nucleophiles with alkyl halides were common. Newcomb's group, attempting to quantitate SET processes, found that the extent of rearrangement did not correlate with the reduction potentials of the nucleophiles or the oxidation potentials of the alkyl halides. Newcomb recognized that a radical-chain isomerization of the substrate, involving radical rearrangements and fast halogenation transfer steps, followed by conventional SN2 reactions of the isomerized alkyl halide would explain the literature data. The interfering radical-chain isomerization was reported in 1987 and Newcomb's subsequent published reviews alerted the chemical community to the problem. To study fast radical reactions, Newcomb's group developed a kinetic technique, the PTOC-thiol method. PTOC esters {PTOC = [((lH)-pyridine-2-thione)oxylcarbonyl} are employed as radical precursors, and a fast hydrogen transfer agent (a thiol or selenol) is used as the competing basis reaction. The method was first used in 1989 by Newcomb and Anne G. Glenn. Subsequently, radicals with lifetimes as short as a few picoseconds have been studied. Newcomb received a B.A. degree from Wabash College, Crawfordsville, Ind., in 1969, and a Ph.D. degree in organic chemistry from the University of Illinois, Urbana-Champaign, in 1973. In 1975, after a postdoctoral appointment with Donald J. Cram at the University of California, Los Angeles, he joined the faculty of Texas A&M University, College Station. He was a Camille & Henry Dreyfus Teacher-Scholar and received the Texas A&M College of Science Distinguished Achievement Award in Teaching in 1985. He joined Wayne State's faculty in 1991. A member of the American Chemical Society, Newcomb chaired the 1993 Gordon Research Conference on Free Radical Reactions.
Jacobsen
Newcomb
The quality of IWAO OJIMA's diverse research accomplishments is as excellent as his international and national reputation. Born in Yokohama, Japan, and educated at the University of Tokyo (B.S. 1968, Ph.D. 1973), Ojima is currently Leading Professor of Chemistry at the State University of New York, Stony Brook. One area of research delved into by the award winner is (3-lactams; he was one of the first to recognize and systematically develop the chemistry of these compounds in that he was instrumental in using p-lactams as building blocks for other compounds, particularly peptides and peptide mimetics. Through his work, he was able to develop an impressive and clever asymmetric route to the side chain of taxol, a chemotherapeutic agent familiar these days because of its potential for treating breast and ovarian cancer. In the area of stereoselective hydrogenation and hydrogenolysis, Ojima is considered to be among the few experts. He applied homogenous catalytic hydrogenation to the enantioselective synthesis of a number of natural and nonnatural amino acids, even extending the hydrogenation method to the synthesis of oligopeptides. Catalytic methods for both carbonylation and silylcarbonylation using mixed metal (cobalt-rhodium) carbonyls have now become a major area of research for Ojima. A colleague says that this is "but one of many exciting efforts that is both pioneering and certainly likely to lead to an opening of new vistas in the rational design of asymmetric catalysts and to the production of new strategies for complex molecule synthesis/' Before coming to the U.S. as an associate professor at Stony Brook in 1983, Ojima had been associated with the Sagami Chemical Research Center in Japan,
Ojima
first as a research fellow and later as a senior research fellow and group leader of the organometallic research group. In 1978 and 1983, respectively, he was also an adjunct lecturer at Tokyo Institute of Technology and Tokyo University of Agriculture & Technology. Among other honors, Ojima received the 25th Progress Award of the Chemical Society of Japan for Excellent Young Investigators in 1976. For four years, he was a member of the Advisory Committee of the National Institute of Health's Medicinal Chemistry Study Section, which evaluates research grants. Ojima is the author or coauthor of about 200 published papers and reviews and holds over 130 patents and patent applications. A widely sought speaker at national and international conferences, he also regularly presents papers at American Chemical Society national meetings. His memberships include ACS, the American Association for the Advancement of Science, and the Chemical Society of Japan. WILLIAM R. ROUSH's research interests focus on the stereocontrolled synthesis of stereochemically complex natural products and on the design and development of new reactions and synthetic methods. Roush, professor of chemistry at Indiana University, is well known for his groundbreaking stereochemical studies and synthetic applications of the intramolecular Diels-Alder reaction. He is also known for his work in asymmetric and acyclic diastereoselective synthesis, specifically the use of tartrate ester-modified allylboronates as reagents for the aldol-like construction of polypropionate- and glycolate-derived systems. He has made important contributions in the synthesis of epoxytrichothecene mycotoxins, carbohydrates, glycosides, and
Roush other polyhydroxylated materials of biological significance, such as the aureolic acid antitumor antibiotics. Roush has analyzed the stereochemistry of the aldol reactions of lithium and boron enolates with a-methyl chiral aldehydes. Roush's analysis suggests that the minimization of gauche pentane interactions in the competing transition states is more important than stereoelectronic considerations. Roush has published a series of papers on the use of 2-alkyl-5-methylenel,2-doxolan-4-ones in highly exo-selective Diels-Alder reactions. Use of this novel dienophile has led to considerable simplification of strategies of the synthesis of several spirotetronate antibiotics. For example, Roush has established that the major hemispheres of chlorothricolide may be assembled in the form of a hexaene precursor, and that both Diels-Alder reactions can be accomplished in a single operation, setting seven asymmetric centers with excellent stereoselectivity. This strategy avoids the functional group compatibility problems associated with classical strategies involving the coupling of fully elaborated top and bottom half intermediates. In the carbohydrate area, Roush has made several important contributions in glycosidation methodology in his work on the synthesis of olivomycin A. He has described an efficient and highly stereoselective synthesis of aryl 2-deoxy-p-glycosides via the Mitsunobu reaction. Roush received a B.S. degree from the University of California, Los Angeles, in 1974, and a Ph.D. degree from Harvard University in 1977. The 1992 Alan R. Day Award of the Philadelphia Organic Chemist's Club was presented to Roush in recognition of his contributions in acyclic diastereoselective synthesis using tartrate ester-modified allylboronates. NOVEMBER 8,1993 C&EN
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AWARDS Chemiluminescence, carbenes, singlet oxygen, azides, and borates—these five topics in modern chemistry are areas in which GARY B. SCHUSTER, head of the chemistry department at the University of Illinois, Urbana-Champaign, has made seminal and pioneering discoveries. Schuster's work has had an impact on industrial approaches to photoimaging and the use of chemilurninescence methods of assay. Schuster received a B.S. degree from Clarkson College of Technology in 1968. After earning a Ph.D. degree from the University of Rochester in 1971, he did postdoctoral work at Columbia University. He joined the University of Illinois faculty in 1975. Schuster's research centers on investigations of the interaction of light with organic compounds. In 1978, with J-Y. Koo, he published a landmark paper that provided a unified mechanistic picture for the chemiluminescence of organic compounds. The paper described the chemically initiated electron-exchange luminescence (CIEEL) mechanism for chemiluminescence and bioluminescence. In CIEEL, the electronically excited state precursor to light formation is formed by annihilation of opposite charged radical ions formed by single electron transfer from the hydrocarbon to the peroxide. A bold idea at the time, the CIEEL mechanism today is recognized as the fundamental process responsible for excitedstate formation in the firefly, luminescent bacteria, and a host of chemiluminescent organic compounds. Schuster has applied ultrafast laser techniques to resolve important mechanistic problems. To examine both the chemical and the physical properties of singlet oxygen, he and his students constructed the first spectrometer capable of detecting the infrared emission of singlet oxygen and analyzing its decay on a microsecond time scale. After reporting an unusual correlation of singlet oxygen lifetime with the number and nature of hydrogen atoms in the solvent, they realized that the correlation corresponded to an electronic-tovibrational energy transfer mechanism. They devised a simple formula to predict the lifetime of singlet oxygen. This approach, too, has stood the test of time. Schuster is internationally recognized for his studies of aryl carbenes and nitrenes. His group is currently studying penetrated ion pairs—a struc50
NOVEMBER 8,1993 C&EN
Schuster
Taylor
rural class in which the specific shape of the constituent ions controls the chemical and physical properties of the ion pair. Another research area is that of the use of photochemistry for the development of information storage and retrieval systems. The first results of his explorations into the uses of phase changes in liquid crystalline media to amplify the effects of a photochemical reaction were published this year. The award winner chaired the 1989 Gordon Conference on Organic Photochemistry and is the 1996 chairman of the Gordon Conference on Electron Donor Interactions. He has authored or coauthored more than 150 research papers and holds 12 patents. He is a member of the American Chemical Society. For many years EDWARD C. TAYLOR, A. Barton Hepburn Professor of Organic Chemistry at Princeton University, has been one of the world's foremost heterocyclic chemists. In a broad sense, his most important work has been his demonstration of the importance of imagination in heterocyclic synthesis. He has proven that rational syntheses of complex systems can be devised by sequential condensation, ring cleavage, and rearrangement reactions. He has developed novel and broadly useful synthetic methods that have made possible the preparation of many important natural products and biologically active compounds. Taylor's contributions are detailed in more than 400 papers, 35 patents, and 74 edited or coauthored books. By using o-aminonitriles as intermediates, Taylor developed simple routes to a wide variety of heterocyclic systems. These contributions were summarized in his 1970 book with Alexander McKillop, 'The Chemistry of Cyclic Enaminonitriles and o-Aminonitriles." Exten-
Verdine
sions of this work led to a general synthetic method for 4-aminopyrimidines and a variety of other functionalized pyrimidines. Taylor was one of the first to recognize and exploit the synthetic potential of the N-oxide grouping in aromatic nitrogen heterocyclic chemistry. His early synthesis of the alkaloid ricinine from 3-picoline and his synthesis of xanthopterin from pterin-8-oxide are outstanding examples of applications of N-oxide rearrangements to synthesis. Perhaps his most significant recent work has come from extensions of fundamental studies on synthesis and reactivity to the preparation of aza- and deaza analogs of the various folate cofactors involved in metabolic one-carbon transfer reactions. A few years ago, Taylor synthesized a novel deazafolate designed to be an inhibitor of de novo purine biosynthesis; this compound (Lome trexol) is currently in Phase II clinical trials for the treatment of solid tumors. More recently, Taylor designed and synthesized a pyrrolo[2,3-d]pyrimidine derivative that is an effective inhibitor of thymidylate synthase; this new antifolate entered clinical trial in 1992, also for the treatment of solid tumors. Taylor has also made important contributions to the use of thallium reagents in organic synthesis. This research program, which he carried out with McKillop over a period of 17 years, led to more than 130 new chemical transformations that are applicable to aliphatic, alicyclic, aromatic, and heterocyclic chemistry. These transformations have astonishing versatility, scope, and specificity and are easy to manipulate. Taylor received B.A. and Ph.D. degrees from Cornell University in 1946 and 1948, respectively. His other honors include Fulbright, Guggenheim,
and Alexander von Humboldt awards; the 1974 ACS Award for Creative Work in Synthetic Organic Chemistry; the 5th International Award in Heterocyclic Chemistry; and the Gowland Hopkins Medal. GREGORY L. VERDINE has established an active group investigating macromolecular recognition and catalysis in protein-DNA complexes. This work has furnished important insights into the chemical basis of complex biological processes. Verdine is Thomas D. Cabot Associate Professor of Chemistry at Harvard University. The tremendous breadth of skills that Verdine has brought to his research program is one reason for his group's success. Verdine has tackled challenging and significant problems in biological chemistry, particularly in the areas of transcriptional regulation, DNA repair, and DNA methylation. His group has been studying DNA repair by the Ada protein, which removes methyl groups from DNA by direct trans-
fer to its own Cys residues. These studies have revealed the surprising finding that a tightly bound zinc in the protein plays an active role in the methyl transfer reaction. Prior to this, zinc was unknown to activate amino acid ligands in proteins. Verdine has reported a powerful strategy for high-resolution chemical analysis of protein-DNA base contacts. Called template-directed interference footprinting, the method is based on molecular design and synthesis, and it offers analysis of amino acid contacts to all four DNA bases in both grooves at single-nucleotide resolution. A companion method involves the use of photoactive nucleosides to determine amino acid residues that make base contacts. Using a novel oligonucleotide suicide substrate, Verdine's group has accomplished the trapping of an essential DNA-processing enzyme—a DNA methyltransferase—in the midst of carrying out its reaction on DNA. Studies on the trapped protein-DNA complex have yielded fundamental insights into the reaction mechanism, and have provided
evidence that the enzyme induces local pairing of its substrate base during DNA methylation. The Cope Scholar's contributions to DNA synthesis chemistry include a method for incorporating unstable baseadducts into DNA site specifically; this method fills an important void in the areas of in-vivo mutagenesis and DNA repair. Verdine and his coworkers were also the first to incorporate disulfide crosslinks into nucleic acids. These crosslinks have been used to force the nucleic acids to adopt a variety of biologically interesting structures. Verdine's lab developed the expression-cassette polymerase chain reaction method and a suite of plasmid vectors, which have become widely used for overproduction of recombinant proteins in bacteria. Verdine received a B.S. degree from St. Joseph's University, Philadelphia, in 1982, and a Ph.D. degree in chemistry from Columbia University in 1986. He completed an NIH postdoctoral fellowship in molecular biology before joining the faculty of
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NOVEMBER 8, 1993 C&EN
Joan K. Vrtis is the winner of the 1993 Sherwin-Williams Student Award in Applied Polymer Science. This award, sponsored by Sherwin Williams Co., and administered through the Joint Polymer Education Committee of the ACS divisions of Polymeric Materials: Science & Engineering (PMSE) and of Polymer Chemistry, is given annually for the best paper presented in PMSE's Sherwin Williams Award Symposium. Vrtis is currently working toward a Ph.D. degree at the University of Massachusetts, Amherst. Her adviser is Richard J. Farris. The title of her paper was "Hysteresis of Biaxial Swelling Stresses in Humidity-Sensitive Polymer Coatings." Other finalists who presented papers were Dan Frich, University of Illinois; Biswaroop Majumdar, University of Texas, Austin; Sutiyao Marturunkakul, University of Massachusetts, Lowell; Timothy E. Patten, University of California, Berkeley; and Richard Venditti, Princeton University. The award, consisting of $500 and a plaque, will be presented to Vrtis at the ACS national meeting in San Diego. • COMMENT Continued from page 45 proximately two pages describing your reasons for applying, what you would seek to accomplish as the fellow, your background in science and public policy, past experience in civic or public affairs, and participation in ACS activities. Two letters of recommendation also must be submitted, and should be sent directly by their authors. The stipend for the 1994-95 fellowship term will be $42,000. Additional sources of funding may be acceptable (for instance, the fellow's employer or private foundations). This tremendous opportunity has the potential to allow you to make your mark on the Washington scene while gaining unique and valuable experience. We were delighted by the response to our call for candidates last year, and it was truly a pleasure for our selection committee to work with such enthusiastic chemists. I encourage you to apply. For more information, phone Gray at (202) 872-4467. The deadline for receipt of application materials is Jan. 1,1994. •
