Olefin cyclopropanation with aryl diazocompounds upon catalysis by a dirhodium(II) complex

A dirhodium(II) complex with N-perfluorooctylsulfonylprolinate ligands is found to catalyze the cyclopropanation of olefins with simple aryl diazomethanes. In this way, diarylcyclopropanes can be obtained in moderate yields with good diastereoselectivity for the cis product.