Catalytic Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Ylides with Vinyl Sulfones

Abstract

[reaction: see text] A general protocol for the enantioselective catalytic 1,3-dipolar cycloaddition of azomethine ylides with aryl vinyl sulfones is described. Nearly complete exo selectivity and enantioselectivities up to 85% ee are attained with Cu(CH(3)CN)(4)ClO(4)/Taniaphos as the catalyst system. The resulting enantioenriched 3-sulfonyl cycloadducts are versatile intermediates in the synthesis of 2,5-disubstituted pyrrolidines.