A Highly Efficient O₂/RuCl₃ System For Catalyzed Cross-Dehydrogenative-Coupling Reactions Between Tertiary Amines And Activated C-H Bonds

One of the challenges synthetic organic chemists facing in the 21th century is the development of mild, excellent selectivity, and highly efficient C-C bond formation reactions via C-H activation mode. The synthetic methods of organonitrogen compounds are always one of chemist widespread studying objects because of their various biological activities. Recently the metal-catalyzed formation of C-C bonds adjacent to a nitrogen atom become one of the hottest spots in modern organic methodology research. Oxygen has some merit such as mild, high-effect, excellent selectivity. It is able to boost various organic reaction proceed under mild condition effectively demonstrating the fine application prospect. Using oxygen as oxidant in the metal-catalyzed reactions to be paid more attention. In this paper a series of reactions promoted were studied and the work we have done are displayed:First, 2(5H)-furanones are a kind of important heterocycle compounds and the synthesis of furanones have always been an area of intensive research by synthetic chemists. In the past methods the preparation of furanones needs advanced and expensive starting material, it couldn't apply in large scale. In summary, we have developed an efficient protocol through the cross-dehydrogenative coupling reaction between tertiary amines and 2-Siloxyfurans catalyzed by O2/RuCl3 system under mild conditions andα-functionalized amines were prepared. In contrast to the method developed, our method uses the cheaper catalyst RuCl3 under the atomsphere of oxygen, reduced the cost greatly and this method provided guarantee to get furanones in large scale.Secend, the nitrocompounds are a kind of important intermediates in the organic synthesis because they have a series of functional group transformation. In this paper, we expensed our substrate for nitroalkanes and studied the coupling reactions between amines and nitroalkanes under O2/RuCl3 system and realized the coupling reaction between tertiary amines and nitroalkanes successfully. This method provided a new way which was simply operated, excellent yields and environmental to get many nitro compound introductions.Third, the malonic acid ester compounds are the important intermediates in dye and spice and also have important use in fields of medicine. In the recent report about the one pot synthesis of malonic acid ester needs tert-butyl hydroperoxide exist some defect such as expensive, explosive, so it was not suit for the industrialization production. In this paper, we studied the coupling reactions between amines and malonates under O2/RuCl3 system and realized the coupling reaction between tertiary amines and nitroalkanes Successfully. The using of oxygen as oxidant instead of tert-butyl hydroperoxide was not only received the target products in excellent yields but also enhance the security and economy of the reaction.From above study, one side providing a new way to the research of C-H activation and extending the breadth of Ru-catalysis and Oxygen, others providing the new and excellent method for the synthesis of complex moleculars by using simple compounds.