Tunable Synthesis of Oxindoles and Sulfonated Oxindoles via Photoredox-Catalyzed C-H/C-H Coupling

Abstract

A novel, mild, and switchable photoredox-catalyzed protocol has been developed for the modular construction of 3,3-disubstituted oxindole architectures. This strategy enables efficient one-pot C-H/C-H coupling of arenes and N-arylacrylamides, yielding either oxindoles or sulfonated oxindoles in moderate to good yields through simple DABSO modulation. The method exhibits broad substrate compatibility, accommodating a wide range of arenes including electron-rich, electron-deficient, and sterically hindered motifs, as well as complex pharmacophore-bearing derivatives. Mechanistic studies confirm a radical-based pathway involving aryl radical intermediates, highlighting the versatility and selectivity of this tunable synthetic platform for accessing structurally diverse oxindole scaffolds with potential pharmaceutical relevance.