Rhodium‐Catalyzed Regio‐ and Enantioselective Intermolecular [4+2] Carbocyclization of 4‐Alkynals with <i>N</i>,<i>N</i>‐Dialkyl Acrylamides

Abstract

Selective rings: A cationic RhI–(R,R)-walphos complex catalyzes a highly regio- and enantioselective intermolecular [4+2] carbocyclization of 4-alkynals with N,N-dialkyl acrylamides to afford enantioenriched cyclohexanones (see scheme; cod=cycloocta-1,5-diene). This new route is attractive in view of the one-step access to 4-alkynals from commercially available reagents.