A novel one-pot synthesis of tetrasubstituted imidazoles under solvent-free conditions and microwave irradiation

Mild, efficient, and chemoselective dehydrogenation of 2-imidazolines, bis-imidazolines, and N-substituted-2-imidazolines with potassium permanganate supported on montmorillonite K-10

Different types of 2-imidazolines, bis-imidazolines, and N-substituted-2-imidazolines are efficiently oxidized to their corresponding imidazoles with potassium permanganate (KMnO4) supported on montmorillonite K-10 under very mild conditions. The procedure is very simple and no strict conditions were required. Selective dehydrogenation of 2-alkyl-2-imidazolines in the presence of 2-aryl-2-imidazolines is a noteworthy advantage of this method and can be considered as a useful practical achievement in these reactions.Key words: 2-imidazolines, imidazoles, dehydrogenation, potassium permanganate, montmorillonite K-10.

Synthesis of Substituted Imidazoles via Organocatalysis

A one-pot synthesis of substituted imidazoles is described. The cornerstone of this methodology involves the thiazolium-catalyzed addition of an aldehyde to an acyl imine to generate the corresponding alpha-ketoamide in situ followed by ring closure to the imidazole in a one-pot sequence. The extension of this methodology to the one-pot synthesis of substituted oxazoles and thiazoles is also described. [reaction: see text]