Asymmetric Carbon-Carbon Bond Formation y to a Carbonyl Group: Phosphine-Catalyzed Addition of Nitromethane to Allenes

摘要

During the past several decades, the development of effective chiral catalysts that generate a new carbon-carbon bond and a new stereocenter a or β to a carbonyl group has been the focus of intense investigation. In contrast, little progress has been described in corresponding catalytic enantioselective functionalizations of the γ position. In 1992, Trost reported that phosphines catalyze the isomerization of electron-poor alkynes and allenes to 1,3-dienes (eq 1).