Intramolecular cyclization of beta,beta-difluoro-o-methyleneaminostyrenes leading to 3-fluoroquinolines is efficiently promoted by a catalytic amount of KCN and a small excess of K2CO3. The reaction proceeds via (i) the generation of intramolecular carbon nucleophiles from imine moieties and (ii) the cyclization by their substitution for the vinylic fluorine.