Catalytic Asymmetric Protonation of Silyl Ketene Imines
摘要:
An efficient catalytic and highly enantioselective protonation of silyl ketene imines is described. The reaction is catalyzed by the chiral phosphoric acids TRIP or STRIP in the presence of a stoichiometric amount of methanol as the proton source and silyl acceptor. A variety of substituted racemic silyl ketene imines have been transformed into highly enantioenriched nitriles.
Catalytic Asymmetric Protonation of Silyl Ketene Imines
摘要:
An efficient catalytic and highly enantioselective protonation of silyl ketene imines is described. The reaction is catalyzed by the chiral phosphoric acids TRIP or STRIP in the presence of a stoichiometric amount of methanol as the proton source and silyl acceptor. A variety of substituted racemic silyl ketene imines have been transformed into highly enantioenriched nitriles.
containing contiguous tertiary and quaternary stereogenic carbon centers were synthesized by using the title reaction. The reaction was catalyzed by a chiral N,N′‐dioxide scandium(III) complex under mild reaction conditions. Based on experimental investigations, a possible transition state has been proposed to explain the origin of asymmetric inductivity.