New alpha-hetero beta-enamino esters 5 (X - NH, O, S) are obtained in good to excellent yields by transamination reactions from ethyl 3-dimethylamino acrylate 2(a-c) and various volatile amines 3(a-e) using solvent-free conditions assisted by focused microwave irradiation. Most of the alpha-hetero beta-enamino ester derivatives 3 present a (E)-s-cis/trans conformation. (C) 1998 Elsevier Science Ltd. All rights reserved.