Recent advances in silver-catalyzed nitrene, carbene, and silylene-transfer reactions

Silver salts are commonly used as Lewis acids in organic synthesis. Silver complexes can also exhibit strong oxidation power due to their high oxidation potentials. This review features the recent development of nitrene, carbene and silylene-transfer reactions catalyzed by silver complexes. Interesting activity was observed in several reactions highlighting the unique redox chemistry of silver. A disilver(I) catalyst was shown to mediate efficient aziridination of simple olefins, intramolecular amidation of saturated C-H bonds and imination of sulfoxides with high regio- and stereoselectivity. Silver compounds also catalyze intermolecular carbene insertion into carbon-halogen bonds, carbon-hydrogen bonds, and aromatic systems. In addition, simple silver salts were found to mediate silylene-transfer reactions to different olefins and alkynes efficiently. Future mechanistic study of these reactions and further exploration of the redox chemistry of silver could lead to more exciting discoveries. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).