Lewis-Acid-Mediated Intramolecular Cyclization of 4-Aryl-5-allyl-1,2,3-triazoles to Substituted Cyclopentene Derivatives.

4-Aryl-5-allyl- N -fluoroalkyl-1,2,3-triazoles available by a three-component reaction of fluoroalkyl azides, copper acetylides, and allyl halides underwent aluminum halide-mediated transformation to N -(4-halo-2-aryl-cyclopentenyl) imidoyl halides by cyclization of vinyl cation intermediates, followed by halide capture. Utilization of the cyclic products was demonstrated by the synthesis of N -alkenyl amides, amidines, isoquinolines, and tetrazoles or by the subsequent modification of the cyclopentene ring.