A solvent-free synthesis of α,α′-bis(substituted benzylidene) cycloalkanones catalyzed by lanthanide amides [(Me3Si)2N]3Ln(µ-Cl)Li(THF)3 under microwave irradiation

Under solvent-free and microwave irradiation conditions, the corresponding E,E′-α,α′-bis(substituted benzylidene) cycloalkanones were prepared in high yields by the cross-aldol reactions of cyclopentanone or cyclohexanone with aromatic aldehydes catalyzed by the lanthanide amides [(Me3Si)2N]3Ln(μ-Cl)Li(THF)3. The reactions produce the products in relatively low yields and require a long time when they were performed in various solvents without microwave irradiation. Thus, the procedure provides a simple and a green synthetic methodology.