Atom and step economic multicomponent synthesis of highly functionalized novel N-alkyl piperidines: structural elucidation through spectral studies and single crystallographic analysis

Abstract

Highly atom economic, one pot synthesis of functionalized tetrahydropyridines by a multicomponent reaction of ethyl acetoacetate, aromatic aldehydes, and aliphatic/aromatic amines in the presence of a catalytic amount of tetrabutylammonium bromide and iodine (TBAB/I₂) at room temperature is reported. The reaction proceeds through the intermolecular Mannich reaction followed by intramolecular Mannich reaction. Notably, this method is mild, cheap, straight forward, applicable to broad range of substrates and environmentally friendly as compared to the accessible methods.