Co(III) ‐Catalyzed Regioselective [4+2]‐Annulation of N‐Chlorobenzamide with Allenes and Vinyl Acetate

Abstract

AbstractA regioselective annulation protocol of N‐chlorobenzamide with allenes and vinyl acetate is reported using a less expensive catalytic system, i. e. Co(III) catalysis and Na2CO3 as base. (CO) NH−Cl acts as both, an internal oxidant and a directing group. Allenes are successfully annulated with N‐chlorobenzamide, providing different exocyclic isoquinolone derivatives in good to moderate yield. Notably, vinyl acetate acts as an acetylene surrogate and undergoes annulation using the developed protocol to provide isoquinolone in excellent yield. Interestingly, in situ deprotection of the acetyl group allowed the quantitative synthesis of hydroxyisoquinolone.