Photo-Driven Regiodivergent Arylation/Cyclization and Arylation/Hydroxylation of N‑Aryl Methacrylamides with Aryltriazenes: Access to Functionalized 3,3-Disubstituted Oxindoles and α‑Hydroxylamides

A metal-free, light-induced regiodivergent functionalization of α,β-unsaturated amides with aryltriazenes under ambient conditions was developed. The visible light and B­(C6F5)3 cocatalyzed radical cascade arylation/cyclization of N-alkyl-N-arylmethacrylamides can obtain functionalized 3,3-disubstituted oxindoles with the assistance of photocatalyst eosin Y–Na2. In the absence of any catalyst, with purple light irradiation and electron-donor–acceptor (EDA) complex initiation, the radical cascade arylation/hydroxylation of N-arylmethacrylamides affords α-hydroxylamides. This methodology highlights the arts in accessing different regioisomers by altering the substrates and photocatalytic strategies.