Chemodivergent photocatalytic access to 1-pyrrolines and 1-tetralones involving switchable C(sp3)–H functionalization

Abstract

A chemodivergent photocatalytic approach to 1-pyrrolines and 1-tetralones from alkyl bromides and vinyl azides has been developed through chemoselectively controllable intermolecular [3 + 2] and [4 + 2] cyclization. This photoredox-neutral two-component protocol involves intermolecular radical addition and switchable distal C(sp 3 )–H functionalization enabled by iminyl radical-mediated 1,5-hydrogen atom transfer. Meanwhile, chemoselectivity between C(sp 3 )–N bond formation and C(sp 3 )–C(sp 2 ) bond formation is precisely switched by photocatalysts (Ru(bpy) 3 (PF 6 ) 2 vs. fac -Ir(ppy) 3 ) and additives (base vs. acid).