Copper-catalyzed Cross-coupling Reaction

Cross-coupling reaction is one the important reactions in organic chemistry. It finds wide applications in chemical engineering and medical syntheses. It is very limited for the traditional synthesis methods due to its specific catalyst and exigent parameters. Recent literatures are focused on the palladium catalyst. Although the catalyst favors the higher cross-coupling efficiency, the high price and strong toxicity of palladium hinder the applications of catalyst, such as in the medical syntheses. At the same time, the catalyst needs large amount of phosphine coordinators that is extremely toxic to the environment.To meet the requirement of the industrial and environmental protection, the study on a high efficiency, low toxic, low price and environmental benign catalytic system is of impending importance. Compared with palladium, copper is a kind of low price and low toxic metal. It is a new trend in the transition metal catalyst and a challenging project in the green process for the chemical engineering to use copper as the catalyst.Sonogashira reaction is an important method to synthesize alkyne substitute which consists of two aromatic rings. A Sonogashira reaction system is designed using CuI as the catalyst, in which multi kinds of coupling reactions of iodobenzene or bromobenzene with alkyne can be processed effectively. Compared with traditional synthetic conditions, the designed method does not use palladium catalyst and is processed without phosphine used as ligands, which favors the industrilization of the current method.Aryl thiocyanates are a kind of the important raw materials in organic synthese. CuI is used in the study to catalyze the reactions of iodobenzene in mild reaction parameters, which truly realizes the synthesis of aromatic rhodamic acid compounds using copper as the catalyst. Compared with those methods in the literature, the current one is facile, environmental benign and with low by-product production.Besides, a new synthesis route to N, N'-aromatic diamide substitute is designed. The first aromatic reaction of hydrazide can be accomplished using CuI as the catalyst, while the second one can be achieved at mild reaction conditions when copper acetate is engaged in the reaction. The designed method overcomes the palladium catalyst process, which is facile and low price.