Theoretical study of a termolecular mechanism for the reaction of (trimethylsilyl)thiazole with carbonyl compounds

A theoretical study was performed on the reaction of 2-silylthiazole with formaldehyde and a termolecular mechanism for the reaction was generated by ab initio calculations. The mechanism predicts the low activation energy of one molecule of 2-silylthiazole and two molecules of formaldehyde. The rection starts with the formation of the N-(siloxymethyl)thiazolium ylide followed by the formation of another intermediate by a nucleophilic addition to a second molecule of aldehyde. 1,6-Silyl migration of the immediate intermediate and the loss of a molecule of aldehyde give the final product.