Regioselective synthesis of pyrano[2,3-d]thiazole derivatives viaDMAP-catalyzed [2+4] annulation of allenoates

Abstract

Herein, a DMAP-catalyzed regioselective [2+4] annulation of allenoates and 5-alkenylthiazolones has been developed for the efficient construction of diverse pyrano[2,3-d]thiazoles with moderate to good yields (27 examples, up to 86% yield). This strategy features a readily available catalyst, facile reaction conditions, broad substrate scope, and high regioselectivity.