Atom Transfer Radical Addition to Styrenes with Thiosulfonates Enabled by Synergetic Copper/Photoredox Catalysis

A synergetic copper/photoredox catalyzed ATRA of styrenes and thiosulfonates is developed. Besides aryl ethylenes, the challenging alpha-substituted styrenes were employed to construct the benzylic quaternary carbon centers. Owing to the mild conditions as well as the high level of substrate compability, this ATRA could be applied to derivatize bioactive natural products in late stage, and to install fluorophores across alkenes. The mechanistic studies reveal sulfonyl radicals as the key intermediate in the transformation.

Automated summary

A synergetic copper/photoredox catalyzed ATRA of styrenes and thiosulfonates has been developed, allowing for the construction of benzylic quaternary carbon centers. The mild conditions and high substrate compatibility make this method applicable for derivatizing bioactive natural products and installing fluorophores across alkenes. Mechanistic studies have identified sulfonyl radicals as key intermediates in the transformation.