Catalyst-free Or Copper(I)-catalyzed Synthesis Of Polycyclic Heterocyclic Compoundscontaining Nitrogen

Construction of heterocyclic compounds containing nitrogen-atom is one of important content in organic chemistry. This paper follows the concept of green chemistry, with as few steps mild conditions, cheap, environmentally friendly catalysts, even under the catalyst-free conditions to build several series of polycyclic heterocyclic compounds containing nitrogen-atom. In addition, Copper-catalyzed Ullmann coupling reaction may conveniently generate sp2 carbon-carbon, carbon-hetero bond, which is an important means in organic synthesis. This article describes the research situation on the construction of polycyclic heterocyclic compounds containing nitrogen-atom at home and abroad in the first chapter, and copper-catalyzed Ullmann reactions are also reviewed in brief.In the second chapter in the absence of a catalyst, using 6-aminoindazole, aromatic aldehyde and 1,3-dicarbonyl compounds as raw materials, four series of polycyclic heterocyclic compounds were synthesized in high regioselectivity by a three-component one-pot reaction. The 1,3-dicarbonyl compounds include 5,5-dimethyl-1,3-cyclohexanedione, 1,3-cyclopentanedione, 2H-indene-1,3-dione and 2-hydroxy-1,4-naphthoquinone. Pyrazolo[3,4-a]acridin-10(6H)-one(4a-4n), cyclopenta [b]pyrazolo[3,4-f]quinolin-9(1H)-one(6a-6m), indeno[1,2-b]pyrazolo[3,4-f]quinolin-11(1H)-one(8a-8k) and benzo[h]pyrazolo[3,4-a]acridine-11,12(6H,13H)-dione derivatives(10a-10l) were obtained, respectively. Finally, a possible reaction mechanism was proposed.In the third chapter, the coupling reaction between sp2-C and N atoms was achieved via the copper(I) catalyzed Ullmann reaction under mild conditions, with tetracyclic nitrogen-containing heterocyclic compounds being obtained expectedly. Using 2-amino-N’-arylbenzohydrazides and 2-halogenated benzaldehydes as reactants, a series of 5-aryl-indazole[3,2-b]quinazolin-7(5H)-one derivatives(13a-13x) were synthesized in high yields catalyzed by CuBr and Cs2CO3. All compounds were characterized by H NMR, 13 C NMR, IR and HRMS.Last chapter, we studied the intro-molecular hydroamination for acetylene catalyzed by copper(I) catalyst. 1-Aryl-pyrazolo[5,1-b]quinazoline-9(1H)-one derivatives(15a-15r) were obtained efficiently by a reaction of 2-amino-N’-arylbenzohydrazides and diethyl acetal catalyzed by CuBr and Cs2CO3The above results show that we can obtain the desired polycyclic heterocyclic compound containing nitrogen-atom under catalyst-free conditions or catalyzed by copper. The procedure has the advantages of mild reaction conditions, high yields, with less catalyst, low toxicity, price cheaper and high regioselectivity.All the products characterized by 1H NMR, IR and HRMS. Some of them were characterized by 13 C NMR, and the structures of 4d, 10 e and 15 d were further confirmed by X-ray diffraction analysis.