Divergent Radical Cyclization and Hydroaminoalkylation of N-Arylacrylamides Using Photoredox Catalysis

The ability to selectively synthesize multiple products from the same sets of substrates is a highly appealing and challenging concept in synthetic chemistry. In this manuscript, we describe the visible-light photoredox intermolecular catalysis of N- arylacrylamides that are alpha-C-H functionalized with aryl tertiary amines. The photocatalyst acts as a chemical switch to trigger two different reaction pathways and to obtain two different products from the same starting material. Simple adjustments to the reaction conditions enable the divergent synthesis of the oxidative cyclizations or the addition products in good to high yields with excellent atom economy.