One-Pot Synthesis of Benzimidazo[2,1-b]thiazoline Derivatives through an Addition/Cyclization/Oxidative Coupling Reaction.

A novel and efficient approach to the synthesis of benzimidazo[2,1-b]thiazoline derivatives has been developed through an addition/cyclization/intramolecular oxidative C-H functionalization process. A variety of alkylene benzimidazo[2,1-b] thiazolines were conveniently assembled from the reaction of aryl isothiocyanate and propargylic amine in the presence of Cu(OAc)2 and PIFA at room temperature. The product could be further converted to substituted benzimidazo[2,1-b]thiazole derivatives.

One-pot synthesis of 2-azolylimidazole derivatives through a domino addition/A3 coupling/cyclization process under copper catalysis.

A novel one-pot approach for the synthesis of multi-substituted 2-imidazolylimidazoles, 2-pyrazolylimidazoles and 2-indazolylimidazoles was developed through a domino addition/A3 coupling/cyclization process under copper catalysis. A variety of aminoethyl- or hydroxylethyl-tethered 2-azolylimidazole derivatives were conveniently and efficiently assembled in one pot using N-propargylcarbodiimides, azoles, paraformaldehyde and secondary amines as starting materials. The products containing an o-iodoaryl group could be further converted to imidazo[1,2-c]imidazo[1,2-a]quinazoline derivatives through a copper-catalyzed intramolecular C-H arylation.

One-Pot Synthesis of 4-Sulfonyliminotetrahydropyrimidin-2-one Derivatives through a Copper-Catalyzed Tandem Reaction.

A novel and efficient synthesis of 4-iminotetrahydropyrimidin-2-one derivatives was developed through a Cu(I)-catalyzed three-component tandem reaction employing propargylamines, isocyanates, and sulfonyl azides as starting materials. A wide range of polysubstituted 4-sulfonyliminotetrahydropyrimidin-2-ones, which might be useful in biological chemistry and medicinal science, were conveniently and efficiently assembled in one pot.