A Metal‐Free Approach Toward Saturated N‐Propargyl Heterocycles via an Annulation/Decarboxylative Coupling Sequence

Abstract A three‐component reaction of a 1,2‐amino alcohol or 1,3‐amino alcohol with a formaldehyde solution and a propiolic acid was developed and studied. This new strategy provided an efficient access to biologically and synthetically important N ‐propargyl oxazolidines, 1,3‐oxazinanes and thiazolidine bearing a diverse range of substituents in good yields. The transformation involves a cascade process that begins with an annulation and is followed by the metal‐free decarboxylative coupling. magnified image