Dual Amine- and Bronsted Acid-Catalyzed alpha-Allylic Alkylation of Aldehydes

A very simple method was developed for the direct, palladium-free catalytic alpha-allylic alkylation of aldehydes. The direct organocatalytic intermolecular alpha-allylic alkylation reaction was mediated by a simple combination of Bronsted acid and enamine catalysis which furnished alpha-allylic alkylated aldehydes and cyclohexanone in high yields and chemoselectivities. The reaction conditions are mild and environmental friendly, the process is conducted under an atmosphere of air without the need for dried solvents, and water is the only side product of the allylic alkylation reaction.