Stereo- and Regioselective Palladium-Catalyzed Intermolecular 3,4-Dialkoxylation of Conjugated Dienes with Aliphatic Alcohols.

In contrast to synthesizing -diether compounds from alkenes via a palladium-catalyzed cascade Wacker-type process, the synthesis of -diether compounds by the method remains a challenge. Herein, a palladium-catalyzed cascade Wacker-type process of conjugated dienes and aliphatic alcohols is reported to synthesize α,β-unsaturated -diether compounds with high stereo- and regioselectivity with a broad substrate scope. Mechanistic experiments have shown that the π-allyl-Pd intermediate formed by the oxypalladation of the conjugated diene is the key to the success of the reaction due to the difficulty of β-hydride elimination.