New alkene cyclopropanation reactions enabled by photoredox catalysis via radical carbenoids

Abstract

We describe the recent emergence of a new approach for the synthesis of cyclopropane rings by means of photoredox catalysis. This methodology relies on the photocatalytic generation of radical carbenoids or carbenoid-like radicals as cyclopropanating species, and its characterized by an excellent functional group tolerance, chemoselectivity and ability to cyclopropane E/Z alkene mixtures with excellent stereocontrol. The mild reaction conditions and the employ of user-friendly reagents are highly attractive features that may find immediate use in academic and industrial laboratories.