Synthesis of alpha,beta-Unsaturated Ketones with Secondary Alcohols and Aldehydes Catalyzed by Fe(acac)(3)

An efficient and environmentally friendly methodology for the direct synthesis of alpha,beta-unsaturated ketones by cross-coupling of secondary alcohols and aldehydes is developed. The transformation is based on Fe(acac)(3)-catalyzed Oppenauer oxidation and Claisen-Schmidt reaction, in which aldehydes are used as oxidants to oxidize secondary alcohols to ketones, and then in situ condensation with aldehydes to form alpha,beta-unsaturated ketones. The reaction proceeds under base-free conditions with a wide range of substrates and good compatibility of functional groups. Gram-scale experiments show the good applicability of this method.