Consecutive Multicomponent Reactions: Synthesis Of 3-Acyl-4-Alkynyi-Substituted 1,3-Thiazolidines

This work describes the synthesis of compounds containing thiazolidine and propargylamidic motifs. Their preparation follows a synthetic route containing two multicomponent reactions. First, the Asinger four-component reaction is used to prepare 3-thiazolines and 3-oxazolines. Secondly, these heterocyclic imines are converted into propargylamides by a copper-catalyzed three-component reaction using acyl chlorides and terminal alkynes. The synthetic route is characterized by mild conditions and many functional groups are tolerated. The formation of an unexpected alpha-alkynoxyamide is also presented.