Transition Metal (Copper,Palladium,Tungsten) Catalyzed Synthesis Of Nitrogen-Containing Heterocyclic Compounds

Transition metal catalyzed construction of nitrogen-containing heterocyclic compounds is a current research hotspot.Although relevant research reports have made breakthroughss,but some reactions themselves also have corresponding shortcomings（for example:need large amount of catalyst,high cost and toxicity reagent,using unstable and highly toxic organophosphine ligand）.This requires us to explore some green,efficient metal catalytic systems.Based on the above problems,the thesis mainly focuses on the synthesis of a series of nitrogenous heterocyclic compound（tetrahydroquinoline,quinoxaline,quinoxaline derivatives）by some green and efficient transition metal（Cu,Pd,W）catalyst systems.1.Firstly,we used the cheap and environmental friendly phosphotungstic acid to catalyze the three-component Diels-Alder reaction of aniline,aldehyde and olefin to synthesize tetrahydroquinoline derivatives.For this reaction,a simple“one-pot”“ball-milling”operation was conducted,readily available starting materials and the inexpensive and environmentally friendly catalyst phosphotungstic acid were employed.A series of tetrahydroquinolines compounds were synthesized in moderate to excellent yields by the“one-pot”“ball-milling”method.2.Based on the excellent properties of polyacids,one bonded-and one discreted-Linqvist hexatungstate-based copper hybrids（Cu-POMs）([Cu₂（O）OH（phen）₂]₂[W₆O₁₉]·6H₂O（1）and[Cu₂（phen）₄Cl][HW₆O₁₉]·2H₂O（2）（phen=1,10-phenanthroline）)were controllably synthesized and routinely characterized.Cu-POMs 1-2 are composed of the same[W₆O₁₉]Unit and a similar copper-phen complex,these two units are combined by the four Cu-O chemical bonds in compound 1,but compound 2 is dispersed and stabilized by intermolecular electrostatic interactions.Thoes compounds can be used to catalyze the one-pot coupling and oxidation reaction of 2-haloaniline with vinyl azide or 3-phenyl-2H-azido under mild conditions to prepare a novel 2-phenylquinoxaline.During the reaction,Cu-POMs 1 showed higher catalytic performance in good yields（79-84%）.The reactions exhibit some functional group tolerance and allow for the preparation of a number of 2-phenylquinoxalines.3.On the basis of our synthesizing coumarin compounds,we try to transform the way to synthesis of quinoline compounds.In this thesis,we synthesized fused chromeno quinolines by the palladium/copper co-catalyzed C-H bond activation and C-C bond cleavage reaction.A variety of fused chromeno quinoline derivatives could be synthesized by coumarin derivatives and anilines through the C-C bond cleavage/C-H functionalization/C-C bond and C-C bond formation process.The MTT assays was used to evaluate the chromeno quinolines against the human cervix tumor cells（HeLa）and we found that chromeno quinolines with electron-withdrawing groups（F,Cl）had a good inhibitory effect on HeLa cells.