The Study Of Copper-promote One-Pot Synthesis Of Benzo N-Heterocyclic Compounds

One of the tasks of organic synthesis is the efficient C-C and C-Y(Y=N, O, S, etc.) bond formation. Transition metal-catalyzed cross-coupling and transition metal-free coupling are two classes of very good strategies for the bond formation. Copper-catalyzed coupling is economic, efficient, green and versatile, making it satisfying with the requirements of industrialization. Thus the method has received considerable attention. With further development and research on transition metal-free coupling in recent years, the condition is becoming more moderate and the application scope is much wider.This paper reported on that with o-haloarylcarbodiimides as the substrates, The one-pot reactions could afford corresponding benzo N-heterocyclic compounds under the copper-catalyzed or transition metal-free conditions. Chapter 1 describes the copper-catalyzed one-pot synthesis of benzimidazole derivatives. We found that the copper-catalyzed one-pot intermolecular addition/intramolecular coupling reactions could successfully occur even at room temperature. We conveniently and effectively synthesized a variety of 2-substituted benzimidazole derivatives.With the development of transition metal-free catalysis, there is also a trend to use the protocol to efficiently assemble various heterocyclic compounds. Our group is also paying attention on the one-pot synthesis of heterocycles under transition metal-free conditions. The second part of the dissertation represents the one-pot assembly of benzimidazole derivatives from o-haloarylcarbodiimides and active methylene compounds in the absence of transition any metal.In the third chapter we efficiently and conveniently synthesized a series of 2-benzimidazolone derivatives from the multi-bond forming cascade hydrolysis/C-N coupling/aza-Michael addition of o-haloarylcarbodiimides with α,β-unsaturated esters.