Phosphine-catalyzed annulation of thioamides and 2-alkynoates: a new synthesis of thiazolines.

The annulation of thioamides with 2-alkynoates and 2,3-dienoates under the catalysis of tri-n-butylphosphine was described. The annulation reaction provided a new entry to thiazolines, particularly those with 2-aryl substituents.