Mild and selective heterobimetallic-catalyzed decarboxylative aldol reactions involving allyl β-keto esters have been developed. The reaction is promoted by Pd (0)-and Yb (III)-DIOP complexes at room temperature and involves the in situ formation of a ketone enolate from allyl β-keto esters followed by addition of the enolate to aldehydes. The reaction is a new example of heterobimetallic catalysis in which the optimized reaction conditions require ...