One-pot four-component synthesis of polysubstituted thiazoles via cascade Ugi/Wittig cyclization starting from odorless Isocyano(triphenylphosphoranylidene)-acetates

A new one-pot four-component preparation of polysubstituted thiazoles by a cascade Ugi/Wittig cyclization has been developed. The four-component reactions of the odorless isocyano(triphenylphosphoranylidene)acetates 1, aldehydes 2, amines 3 and thiocarboxylic acids 4 produced 2,4,5-trisubstituted thiazoles 5 in moderate to good yields in the presence of triethylamine. The two-component reactions between isocyano(triphenylphosphoranylidene)acetates 1 and thiocarboxylic acids 4 in the presence of triethylamine provided the corresponding 4,5-disubstituted thiazoles 6 in good yields as well. (C) 2020 Elsevier Ltd. All rights reserved.