A Bulky Thiyl-Radical Catalyst for the [3+2] Cyclization of N-Tosyl Vinylaziridines and Alkenes.

Thiyl-radical-catalyzed cyclization reactions of N-tosyl vinylaziridines and alkenes were developed as a new synthetic method for the generation of substituted pyrrolidines. The key to making this process accessible to a broad range of substrates is the use of a sterically demanding thiyl radical, which prevents the undesired degradation of the catalyst.