Synthesis of polysubstituted fused pyrrolidines via [2 + 2]/[2 + 3] cycloaddition of azomethine ylides

Abstract

A general approach to dense substitution patterns via [2 + 2]/[2 + 3] cycloaddition between nonstabilized azomethine ylides, alkynes and silyl enol ethers is elaborated. This approach not only allowed the preparation of novel molecules, but also significantly simplified the synthesis of the existing ones. 3-Azabicyclo[3.2.0]heptanes which contain polysubstituted cyclobutanes could be obtained in medium to good yields with excellent diastereoselectivities.