The inversion of the normal reactivity (umpolung) of aldehydes has been induced via N- heterocyclic carbenes (NHCs) thiazol-2-ylidenes 2a or 3a, generated by simple electrolyses of solutions containing thiazolium salt 2 or 3. Accordingly, 1, 4-dicarbonyl compounds have been obtained, in mild conditions and in moderate to very high yields, via 1, 4-addition of the Breslow intermediates to the suitable Michael acceptor. The procedure has been ...
