Visible-light-induced diastereoselective synthesis of β-lactams via a Cu(i)-catalyzed cascade 1,5-H shift/cyclization

Abstract

We herein report a visible-light-driven, copper(i)-catalyzed intramolecular 1,5-hydrogen atom transfer (1,5 HAT)/cyclization that provides efficient access to β-lactams with good to excellent diastereoselectivity. The copper catalyst plays a dual role, functioning both as a photosensitizer and as a Lewis acid to facilitate the cyclization step. Notably, the diastereoselectivity of the terminal cyclization can be effectively modulated through ligand design, marking a key advance in energy transfer catalysis. This work represents a notable advance in copper photocatalysis and offers an efficient, environmentally benign route to β-lactam scaffolds.