PHOTOCATALYTIC ISOQUINOLINE PRODUCTION AND N-ALKYLATION BY PLATINIZED TITANIUM(IV) OXIDE PARTICLES SUSPENDED IN ALCOHOLIC SOLUTION OF PHENETHYLAMINES

Photocatalytic ($\lambda$$_{ex}$ > 300 nm) reaction at room temperature by platinized titanium (IV) oxide particles produced 1-methyl-1, 2, 3, 4-tetrahydroisoquinolines (MIQ's) from phenethylamines in aqueous ethanol suspension under deaerated atmosphere. Among the phenethylamines, dopamine (2-(3, 4-dihydroxyphenyl) ethylamine) showed the highest reactivity to give MIQ almost selectively under the neutralized conditions. The other phenethylamines gave predominantly N-alkylated and N, N-dialkylated products in the methanol or ethanol solutions. The reaction mechanism includes a Schiff base intermediate to undergo either nucleophilic attack leading to MIQ or reduction to N-alkylated products.