Acidic ionic liquids catalyzed one-pot, pseudo five-component, and diastereoselective synthesis of highly functionalized piperidine derivatives

Abstract

An efficient and one-pot quantitative procedure for the preparation of functionalized piperidine derivatives from pseudo five-component reactions of aromatic aldehydes, substituted anilines, and ethyl/methyl acetoacetate (molar ratio: 2/2/1) in the presence of acidic ionic liquids such as 1-methylimidazolium hydrogen sulfate ([Hmim]HSO4), 1,1,3,3-tetramethylguanidinium perchlorate ([TMG]ClO4), and 1,1,3,3-tetramethylguanidinium trifluoroacetate ([TMG]TFA) as the catalysts has been developed. The ionic liquids were stable during the reaction process and could also be reused several times without significant loss of their activities.