Co(III)-Catalyzed Annulative Vinylene Transfer via C–H Activation: Three-Step Total Synthesis of 8‑Oxopseudopalmatine and Oxopalmatine

The Co­(III)-catalyzed redox-neutral annulation of benzamides and acrylamides with vinylene carbonate for the synthesis of isoquinolinones and pyridinones has been developed. This protocol employing inexpensive Co­(III) as the catalyst tolerated diverse functional groups and substitution patterns, affording the target products with good to excellent yields. The synthetic utility of this transformation was demonstrated by a three-step synthesis of gusanlung D, 8-oxopseudopalmatine, and oxopalmatine.