Herein, a coupling reaction of enol ethers with silyl ketene imines in the presence of catalytic amounts of InBr3 and Me3SiBr is described. Kinetic studies have revealed that an indium catalyst and Me3SiBr accelerated the coupling process and the regeneration of the catalyst, respectively. Various types of enol ethers and silyl ketene imines are applicable. In addition, a formal synthesis of verapamil
A highly enantioselective Mannich reaction of silyl ketene imines with isatin‐derived ketimines has been realized by using a chiral N,N′‐dioxide/ZnII catalyst. A variety of β‐amino nitriles containing congested vicinal tetrasubstituted stereocenters were obtained with excellent outcomes (up to 98 % yield, >19:1 d.r. and 99 % ee). Based on the experimental investigations, a possible transition state
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.