Copper-Catalyzed Synthesis Of Quinoxalines And2-Substituted Benzimidazoles In The Presence Of Basic Conditions

Quinoxalines and benzimidazoles play an important role as very important six or five-membered nitrogen-containing heterocyclic compounds. In the paper, we introduced the different applications and artificial synthesis of quinoxalines and benzimidazoles. And then, the new synthetic strategies of quinoxalines and2-substituted benzimidazoles were proposed. This thesis includes two parts:First, the synthesis of quinoxalines was introduced. Recently, many researches have proved that quinoxalines were used widely in pesticide, electroluminescent materials, dye, feedstuff and so on. Tradition synthetic strategies for the preparation of substituted quinoxalines are efficient processes, however, they all resulted in the formation of regioisomers of the products when1,2-diamines were employed as starting materials. Herein, we report an efficient method with which to synthesize quinoxalines involving copper-catalyzed, one-pot, three-component reactions of2-iodoanilines, phenylacetaldehydes and NaN3in the presence of base (K2CO3). The approach avoids production of regioisomers in the products through the use of sodium azide as the nitrogen source.Second, the synthesis of2-substituted benzimidazoles was introduced. Benzimidazoles show high biological activity in weeding, pesticides, regulator of plant growth, sterilization and so on. Although tradition synthetic strategies for the preparation of2-substituted benzimidazoles which employ1,2-diamines as starting materials are efficient processes, they all resulted in regioisomers in the products. The paper introduce a novel way to synthesize2-substituted benzimidazoles from2-iodoanilines and amides by Cu(Ⅰ) and base (K3PO4·3H2O) under short reaction times and avoids the the formation of regioisomers in products.