4-Difluoromethylated Quinoline Synthesis via Intramolecular SN2 Reaction of (alpha)-Trifluoromethylstyrenes Bearing Imine Moieties

Intramolecular cyclization of o-methyleneamino-substituted (alpha)-trifluoromethylstyrenes is promoted by DBU and a catalytic amount of KCN to provide 4-(difluoromethyl)quinolines. The reaction proceeds via (i) the generation of carbon nucleophiles from the imine moieties, (ii) their intramolecular SN2ʹ reaction with loss of a fluoride ion, and (iii) subsequent aromatization by alkene isomerization.