[4+2]Type Cycloaddition of Aldimines Bearing α-Hydrogens with 2-Siloxy-1, 3-butadienes Catalyzed by Trimethylsilyl Triflate

Abstract

[4+2]Type cycloaddition of unactivated imines bearing α-hydrogens with 2-siloxy-1,3-butadienes has been performed efficiently by using trimethylsilyl triflate as a catalyst. The relative stereochemistry in the major diastereomers of the cycloaddducts has been assigned to be trans between C(2) and C(6) substituents.