Dearomatization of Electron-Deficient Indoles with N-Alkylanilines via Visible-Light-Induced Hydroalkylation

Herein, a visible-light-induced, base-promoted 3 + 2 annulation was developed for the dearomatization of electron-deficient indoles with readily available N -alkylanilines, affording valuable tetrahydropyrrolo[3,4- b ]indol-1(2 H )-ones with high diastereoselectivity. This protocol features excellent atom economy, a broad substrate scope with exceptional functional group tolerability, and compatibility with continuous-flow conditions. Mechanistic studies suggest that photoredox catalysis generates N -α-carbon radicals, which undergo radical addition to indoles, followed by amidation, providing an efficient and scalable route to indoline derivatives.