Synthesis of 3,4-unsubstituted isoquinolone derivatives from benzimidates and vinylene carbonate <i>via</i> cobalt(<scp>iii</scp>)-catalyzed C–H activation/cyclization

A cobalt(III)-catalyzed C-H activation/cyclization of benzimidates and vinylene carbonate has been developed. Various benzimidates showed good compatibility, providing isoquinolone derivatives in moderate to good yields. This strategy employs the inexpensive Co(III) as the catalyst and provides an efficient and practical solution for the synthesis of medicinally valuable 3,4-unsubstituted isoquinolone derivatives.