Editorial pubs.acs.org/CR
Introduction to Reactive Intermediates
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Finally, the editor wishes to thank the contributors for their arduous and thorough efforts, as well as Guy Bertrand and the staff of Chemical Reviews for their patient cooperation and overall stewardship.
ow you see it; now you don’t: Hermes Trismegistus, the chemist as magician. When I began my career, not so long after the middle of the last century, spectroscopy was slow. Radicals could be observed, as long as they were heavily decorated with aromatic substituents; carbocations could be seen in solution, when the solvent was sulfuric acid; carbenes were stable, if carbon monoxide or isonitriles satisfied your definition of a carbene, or if matrix isolation under cryogenic conditions sufficed. We were definitely in the “now you don’t” era. Gradually, spectroscopy became faster: stopped-flow, flash photolysis, laser flash photolysischemists chipped away at time in units of 103ms, μs, ns, ps, fs. Even the most fleeting intermediate could be illuminated. Simultaneously, the processing power and the speed of computers greatly increased. Today we are in the “now you see it” age; we can even observe the spectra of excited states and compute their geometries and energies. Reactive intermediates that were only postulates in the early days of physical organic chemistry are now welldescribed chemical species; mechanisms that were inferred from products have been confirmed by direct observation. This special issue of Chemical Reviews is devoted to the modern chemistry of reactive intermediates. Here are ten reviews from the frontiers of a vibrant field. Klumpp et al. review contemporary carbocation chemistry with an emphasis on applications to organic synthesis. Kenttämaa and colleagues describe the chemistry of radical cations in the gas phase, while Tian and Kass review carbanions under similar conditions. Abe considers diradical chemistry, a topic that is also examined in a mechanistic context by Alabugin et al. with special emphasis on the details of cycloaromatization reactions. The vexed topic of the structure and reactivity of organolithium reagents is considered in great depth by Reich. Two reviews deal with carbene chemistry: Heteroarylcarbenes are examined by Sheridan, and the addition of carbenes to fullerenes is considered by Akasaka et al. Those readers seeking further news from the divalent carbon front are referred to Contemporary Carbene Chemistry, a forthcoming, wide-ranging, edited volume with 16 chapters devoted to both transient and stable carbenes that focuses equally on mechanistic and synthetic aspects.1 Carpenter examines the disposition of energy in reactive intermediates and how excess internal energy can affect the distribution of reaction products. Finally, Allen and Tidwell describe the reactions of ketenes and cumulenes. Inevitably, some important classes of reactive intermediates are not represented in this collection. The omissions are both by design and necessity. Nitrenes and nitrenium ions are in the former category. An excellent edited volume containing 12 chapters devoted to these species has just appeared, and it seemed excessive to include them here.2 As for necessity, a number of planned reviews fell by the wayside during the gestation of this issue: silylenes, polyradicals, tetrahedrane and cyclobutadiene derivatives, and radical ions are among the topical areas that unfortunately could not be included. © 2013 American Chemical Society
Robert A. Moss
Rutgers University
AUTHOR INFORMATION Notes
Views expressed in this editorial are those of the author and not necessarily the views of the ACS. Biography
Robert A. Moss is Research Professor and Louis P. Hammett Professor Emeritus at Rutgers University, The State University of New Jersey, in New Brunswick, New Jersey. A 1960 graduate of Brooklyn College, he received his doctorate from the University of Chicago in 1963 under the direction of Professor G. L. Closs. After a NAS-NRC Postdoctoral Fellowship with Professor Ronald Breslow at Columbia University, he joined the faculty at Rutgers University in 1964. He has remained at Rutgers with the exception of research leaves at M.I.T., the University of Oxford, the Weizmann Institute of Science, and the Hebrew University of Jerusalem. Professor Moss and his colleagues have authored more than 400 scientific publications, including 8 coedited books. These contributions have dealt with reactive intermediates (carbenes, carbocations, carbanions), reactions in organic aggregates (micelles and liposomes), and the decontamination of toxic organic phosphorous compounds. He has been a Fellow of the Alfred P. Sloan Foundation, and is currently a Fellow of the American Chemical Society and the American Association for the Advancement of Science. In 2010 he received an Arthur C. Cope Scholar Award from the American Chemical Society. He retired from full-time teaching in 2007 to focus his efforts on research. This activity continues with assistance from the National Science Foundation, which has supported his research continuously for more than half a century. Special Issue: 2013 Reactive Intermediates Published: September 11, 2013 6903
dx.doi.org/10.1021/cr400279e | Chem. Rev. 2013, 113, 6903−6904
Chemical Reviews
Editorial
REFERENCES (1) Moss, R. A., Doyle, M. P., Ed.; Contemporary Carbene Chemistry; Wiley: Hoboken, NJ, in press. (2) Falvey, D. E., Gudmundsdottir, A. D., Ed.; Nitrenes and Nitrenium Ions; Wiley: Hoboken, NJ, 2013.
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dx.doi.org/10.1021/cr400279e | Chem. Rev. 2013, 113, 6903−6904
