A novel three-component tandem protocol for the regioselective synthesis of 1-(2-arylmethyl-5-aryl-3-thienyl)pyrrolidines and piperidines

A series of new substituted 1-(2-arylmethyl-5-aryl-3-thienyl)pyrrolidines and piperidines were synthesised by one-pot, three-component tandem reactions of 5-aryldihydro-3(2H)-thiophenone, aromatic aldehydes and pyrrolidine/piperidine under solvent-free microwave irradiation. This facile transformation occurs presumably via a tandem enamine formation–carbonyl addition–dehydration–isomerisation sequence.