Coupling Reaction Based On Carbonyl Or N-heterocycli Compounds As Nucleophiles

Metal catalysts can be found everywhere and many synthetic advances are directly linked to scientific progress and developments in catalytic chemistry. As we all know, the discovery of new agents, new reactions and new methods is of endless. This paper firstly describes the history and development of organometallic chemistry of transition metal coupling reactions involved in the development of profiles, and highlights the current development of transition metals copper and transition metal coupling reaction without participation of the two nucleophiles. In this paper, most of the work were conducted to design a new type of carbon-carbon, carbon-oxygen coupling reaction using copper as a catalyst through scientific and rational methods and carbon-oxygen coupling reaction studies taking simple organic bases as promoting agent. Meanwhile, based on kinetics way, the mechanism of the reaction has been explored, especially for the generation of reactive reaction intermediates for further research The paper reveals the key of the coupling reaction. It mainly consists of the following three parts:1: Copper-catalysed oxidative Csp3-H methylenation to terminal olefins using DMFA copper-catalysed direct oxidative Csp3-H methylenation to terminal olefins using DMF as onecarbon source was developed. In this reaction, various functional groups were well tolerated, thus providinga simple way to construct arylvinylketones and arylvinylpyridines. The preliminary mechanisminvestigations revealed that CH2 was from DMF(N-CH3). and this reaction occurred without any inductiveperiod from the result of operando IR.2: Base-Promoted Synthesis of Coumarins from Salicylaldehydes and Aryl-Substituted 1, 1-Dibromo-1-alkenes under Transition-Metal-Free ConditionsFacile synthesis of coumarin via the tandem reaction of salicylaldehyde with aryl-substituted 1, 1-dibromo-1-alkene was developed. This new protocol proceeds smoothly under mild and transition-metal-free conditions, it allows rapid access to coumarins containing various heteroatoms that are more difficult to prepare by traditional methods. Based on the isolated intermediate of 4-(diethylamino)-3-phenylchroman-2-one and detailed mechanistic studies, a credible tandem pathway was proposed.3: Chloroacetate-Promoted Selective Oxidation of Heterobenzylic Methylenes under Copper CatalysisEfficient selective oxidation and functionalization of C-H bond with molecular oxygen to prepare the ketones by using a copper catalyst were achieved with ethyl chloroacetate as a promoter. In this transformation, various substituted N-heterocyclic compounds were well tolerated. Preliminary mechanistic investigations indicated that organic radical species were involved in the overall process. The N-heterocyclic compounds and ethyl chloroacetate work synergistically to activate the C-H bonds in the methylene group which in turn results in the easy generation of the free radical intermediates, thus leading to the good yields of corresponding ketones.