Carbenic reactivity revisited

• Published in: Accounts of chemical research Vol. 22; no. 1; pp. 15 - 21
• Main Author: Moss, Robert A
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01.01.1989
• Subjects: 400201 - Chemical & Physicochemical Properties; ALKENES; CALCULATION METHODS; CARBENES; DATA ANALYSIS; DOCUMENT TYPES; HYDROCARBONS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; KINETICS; MEASURING METHODS; ORGANIC COMPOUNDS; RADICALS; REACTION KINETICS; REACTIVITY; REVIEWS
• ISSN: 0001-4842; 1520-4898
• DOI: 10.1021/ar00157a003

In 1980, we published an Account of Carbenic Selectivity in Cyclopropanation Reactions. There, we attempted to show how simple competitive kinetics experiments, together with frontier molecular orbital (FMO) theory, could rationalize the selectivities expressed in this simplest of cycloaddition reactions, the (1 + 2) addition of a singlet carbene (CXY) to an alkene. The study of carbene/alkene additions has since increased in importance. The reactants are small enough to be the subject of high quality ab initio calculations, so that (at least portions of) reasonably accurate energy surfaces can be generated for these cycloadditions. Moreover, current spectroscopic and fast kinetic methods make it possible to derive experimental data for comparison with the theoretical results. Together, these two approaches promise to yield instructive paradigms for chemical reactivity theory. However, we warned that although we possessed a workable, predictive, semiquantitative theory and a parallel body of congruent experimental results, we should be prepared for modifications upon the advent of new computational or experimental data, particularly absolute rate constants for CXY/alkene additions. In the Account we will try to integrate the new results into a coherent overview.