Practical aldol reaction of trimethylsilyl enolate with aldehyde catalyzed by N-methylimidazole as a Lewis base catalyst

Aldol reaction of trimethylsilyl enolate with aldehyde proceeded in the presence of a catalytic amount of a Lewis base, N-methylimidazole, and lithium chloride in DMF at room temperature. Not only aryl aldehyde but also alkyl aldehyde provided the aldol product in satisfactory yields. The reaction was mild enough to apply to the aldehyde having HO, AcO, THPO, TBDMSO, MeS, pyridyl or olefinic group. Microwave irradiation accelerated the reaction.