Facile Synthesis of Onychines

Abstract

The FeCl3-mediated condensation of an α-phenylenamino ester and an enone proceeds efficiently to afford a 2-phenylnicotinate. The subsequent intramolecular Friedel–Crafts reaction yielded an ­onychine framework. Modifications at the 2-, 3-, and 8-positions of the onychine framework were easily achieved by altering the enamino esters­ and enones, which facilitated the discovery of potentially bioactive compounds.