Thiazolium carbene-catalyzed reactions of 1,2-diketones and 1,2,3-triketones with enones and ynones have been investigated. The diketones gave α,β-double acylation products via unique Breslow intermediates isolable as acid salts, whereas the triketones formed stable adducts with the NHC instead of the coupling products.

A series of new 2,3,5-triaryl-substituted oxazolium and thiazolium salts are readily prepared by a Tf(2)O-mediated intramolecular cyclisation and their use as precursors for the synthesis of novel oxazol-4-ylidene and thiazol-4-ylidene rhodium complexes has been developed.

Carbon materials that are intrinsically co-doped with nitrogen and sulfur heteroatoms are synthesised by facile annealing of nitrile-functionalised thiazolium salts. Extremely high degrees of doping are achieved, especially for sulfur. The method further allows for direct tuning of the amounts of both N and S, establishing a new synthetic pathway in the emerging field of S-doped carbon materials.

Thiazolium carbene-catalyzed reaction of aromatic 1,2-diketones with enones in aprotic solvents gave double acylation products in good yields, whereas hydroacylation products formed by Stetter reaction were not detected at all. These results suggested the generation of aroyloxyenamine species from the 1,2-diketones instead of hydroxyenamines (Breslow intermediates).

The catalytic N-formylation and N-methylation of amines using CO2 as the carbon source represents a facile and sustainable approach for the synthesis of pharmaceuticals and natural products. Herein, we describe highly effective and inexpensive thiazolium carbene-based catalysts derived from vitamin B1 for the N-formylation and N-methylation of amines, using polymethylhydrosiloxane (PMHS) as a r...

The structures of 2-acetamido-4-tolyl-1,3-thiazole, C(12)H(12)N(2)OS, (I), and 2-amino-4-tolyl-1,3-thiazolium chloride dihydrate, C(10)H(11)N(2)S(+).Cl(-).2H(2)O, (II), reveal that both molecules are essentially planar, with the respective dihedral angles between the benzene and thiazole rings being 2.9 (1) and 10.39 (7) degrees . Compound (I) associates via a single N-H...O interaction to form...