Redox-Tuned Oxycarbamates Enable Divergent C─N and C─C Functionalization of Indolizines Under Photoredox Catalysis With Green Light.

Abstract

Nitrogen-centered radicals (NCRs) provide direct access to C─N bonds, but their broader use remains limited by the need for strongly reducing photocatalysts, high-energy irradiation, and incomplete control over competing radical transfer pathways. Here we show that nonafluoromesitylsulfonyl (Nms)-substituted oxycarbamates represent a redox-lowered class of amidyl-radical precursors that can be activated under green light by a bichromophoric ruthenium photocatalyst. The electron-deficient sulfonyl group lowers the reduction potential of the N─O bond sufficiently to enable single-electron cleavage under mild conditions. In DMF, the resulting amidyl radicals are trapped directly by indolizines to provide C3-aminated heteroarenes. In DMSO, higher N-alkyl homologues are switched via a 1,2-hydrogen atom transfer (HAT) to α-amino carbon-centered radicals, enabling C─C bond formation from the same precursor family. This solvent-gated divergence provides a unified entry to aminated and alkylated indolizines and establishes redox-tuned oxycarbamates as versatile radical precursors for long-wavelength photoredox synthesis.