Microwave-assisted domino reactions of propargylamines with isothiocyanates: selective synthesis of 2-aminothiazoles and 2-amino-4-methylenethiazolines

A simple and versatile microwave-assisted protocol for the synthesis of 2-aminothiazoles has been developed. The domino reaction of propargylamines and isothiocyanates in the presence of catalytic PTSA leads to the selective synthesis of 2-aminothiazoles at temperatures above 130 °C and in a few minutes. The same reaction carried out at lower temperatures leads to the formation of the tautomeric 2-amino-4-methylenethiazolines.