Rhodium-Catalyzed Regio- and Enantioselective Intermolecular [4+2] Carbocyclization of 4-Alkynals with N,N-Dialkyl Acrylamides

摘要

Transition-metal-catalyzed cycloaddition is a powerful synthetic method for the construction of cyclic frameworks.In particular,[4+2] cycloadditions of dienes or enynes with alkynes or alkenes have been widely examined for the construction of six-membered-ring systems.However,[4+2] cycloadditions via cyclic acyl metal intermediates to give six-membered carbonyl compounds are rare.Furthermore,although some transition-metal-catalyzed enantiose-lective intramolecular [4+2] cycloadditions have been reported,enantioselective intermolecular [4+2] cycloaddition has not been established.