Rhodium-catalyzed tandem aldol condensation-Robinson annulation between aldehydes and acetone: synthesis of 3-methylcyclohexenones

A simple catalytic, redox-neutral access to 3-methylcyclohexenones has been developed via rhodium catalysis in the presence of an amine additive and Ag2CO3. This process utilized simple aldehydes and acetone as substrates and tolerates a variety of functional groups. Disubstituted phenols were isolated in moderate yields when Cu(OAc)2 was employed as an oxidant.