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

Abstract

A 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.

Inherent directing group-enabled Co(iii)-catalyzed C–H allylation/vinylation of isoquinolones

“…12 Hence, we aim to overcome these challenges associated with oxo-directed C–H functionalization using high-valent cobalt catalysis (Scheme 1). In continuation of our work on cobalt-catalyzed C–H functionalization, 13 herein we reported the cobalt-catalyzed inherent directing group enabled C(8)–H allylation and vinylation of isoquinolones using readily available surrogates.…”