Cu(I)-Catalyzed Enantioselective [3 + 2] Cycloaddition Reaction of 1-Alkylallenylsilane with α-Imino Ester:  Asymmetric Synthesis of Dehydroproline Derivatives

The catalytic, enantioselective [3 + 2] cycloaddition reaction of 1-alkyl-substituted allenylsilanes with α-imino ester has been achieved by means of [Cu(MeCN)4]BF4/(R)-DM-SEGPHOS catalyst to afford silyl-substituted dehydroproline derivatives in high yields and enantioselectivities.