Visible‐Light Induced Radical Cyclization of N ‐Allylbenzamide with α ‐Carbonyl Alkyl Bromide for Direct Construction of Dihydroisoquinolones

Abstract A visible‐light‐induced radical cyclization of N ‐allylbenzamide has been established as an efficient and versatile approach for synthesizing structurally diverse dihydroisoquinolones. Under the catalysis of fac ‐Ir(ppy) 3 , the N ‐allylbenzamide substrate intercepts an alkyl radical, triggering an intramolecular cyclization cascade followed by proton extrusion to furnish the dihydroisoquinolinone scaffold. This protocol is distinguished by its high efficiency, operational simplicity, broad substrate scope, and excellent tolerance to a wide range of functional groups.