REGIOSELECTIVE REDUCTION OF 1-METHYLQUINOLINIUM IONS BY TRIBUTYLTIN HYDRIDE AND TRIS(TRIMETHYLSILYL)SILANE VIA PHOTOINDUCED ELECTRON-TRANSFER

Thermal reduction of 1-methylquinolinium ion by tributyltin hydride oc curs via a polar mechanism to yield 1-methyl-1,2-dihydroquinoline sele ctively, white the photoreduction of 1-methytquinolinium ion derivativ es by tributyltin hydride and tris(trimethylsilyl)silane proceeds via photoinduced electron transfer from the metal hydrides to the singlet excited states of 1-methylquinolinium ion derivatives to yield the cor responding 1,4-dihydroquinolines exclusively.