Efficient synthesis of five- and seven-membered-ring heterocycles by rhodium(II)-catalyzed [3+2] and [3+4] cycloaddition of diazodicarbonyl compounds with conjugated dienes

摘要

Rhodium(II) -catalyzed reactions of diazodicarbonyl compounds with a variety of conjugated dienes have been examined. These reactions provide a simple and rapid route to dilrydrofurans and dihydrooxepines with a variety of substituents on the ring. The formation of these products is interpreted in terms of a stepwise mechanism. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).