Copper-Catalyzed Cycloaddition of Bis-Sulfonyl Ethylene

Significance

Asymmetric [3+2] cycloadditions of azomethine ylides are one the most efficient protocols for the preparation of chiral pyrrolidines. The major drawback of these reactions is the limitation in substrate scope of electron-deficient dipolarophiles. In this report, Carretero and co-workers introduce bis-sulfonyl ethylene which acts as an acetylene surrogate, species which are unprecedented substrates for cycloaddition with azomethine ylides.