N-Heterocyclic Carbenes Catalyzed One-Pot Synthesis Of2,3-Diaryl Quinoxaline And2-Amino-4,5-Diphen Ylthiazole

Since1991, the first Arduengo reported a stable nucleophilic N-heterocyclic carbine,because its Stability in the air and activity properties, N-heterocyclic carbenes as anOrganocatalyst have made fruitful achievements in organic synthesis. This paperintroduces the application of the n-heterocyclic carbenes in organic synthesis and focuseson benzimidazolium Precursor Salts served as organocatalyst for organic reacations.In part one, A one-pot facile protocol for the direct synthesis of quinoxalinederivatives via tandem Benzimidazolium salt as N-heterocyclic carbene (NHC) Precursor Salts, then oxidant through air without separation. after that1,2-diaminobenzene was added into the solvent to get the corresponding2,3-diaryl quinoxaline. This reaction is very convenient.In part two, A one-pot facile protocol for the direct synthesis of quinoxalinederivatives via tandem Benzimidazolium salt as N-heterocyclic carbene (NHC)Precursor Salts, thionyl chloride was added as chlorination agent, after full reaction, thenget ride of redundance chlorination agent. Take the water as solvent, thiourea was addedinto reaction to obtained corresponding2-Aminothiazole.