Regioselective Alkylation of Vinylogous N-Acyliminium Ion, Leading to 6-Alkyl-1,2,3,6-tetrahydropyridines, by Using Electrogenerated Acid (EG acid) as a Catalyst
Alkylation of 6-methoxy-1,2,3,6-tetrahydro- and 4-methoxy-1,2,3,4-tetrahydropyridines with organo-silicon compounds as a carbon nucleophile by using electrogenerated acid as an acid catalyst proceeds regioselectively at the C-6 position via vinylogous acyliminium ion, while sulfenylation and methoxylation occurs at the C-4 position.