Selective N-α-C-H alkylation of cyclic tertiary amides via visible-light-mediated 1,5-hydrogen atom transfer

Herein, we report an effective C-H bond activation-alkylation strategy for 2-iodobenzoyl protected cyclic amines at the N-& alpha;-position through a visible-light mediated 1,5-hydrogen atom transfer (HAT) process. The readily reducible C-Ar-I bond was selected as an appropriate precursor to generate aryl radicals, which would further trigger an intramolecular HAT process to access the key N-& alpha;-radicals. Scale-up reaction and several examples of late-stage functionalization on structurally complex bio-active molecules demonstrate the synthetic potential of this protocol.