Highly efficient and chemoselective direct aldol reaction of acyldiazomethane with aldehydes promoted by MgI_2 etherate

摘要

Direct aldol condensation of various aromatic, heteroaromatic, α,β-unsaturated aldehydes and aliphatic aldehydes with acyldiazomethane was realized using MgI_2 etherate(MgI_2·(Et_2O)_n)as a promoter in the presence of diisopropyl amine(DIPEA) in excellent yields in a short time under mild conditions with high chemoselectivity. Iodide counterion, and a non-coordinating less ploar reaction media(i.e., CH_2Cl_2) are among the critical factors for this unique reactivity.