Studies On The Amination Of Aryl Chloride Catalyzed By Well-defined NHC-Pd Complexes (NHC=N-Heterocyclic Carbene)

In this thesis, some palladium NHC complexes with different neutral leaving group which had been reported were prepared. In addition, we investigated the catalytic ability of these complexes as precatalysts in the amination of aryl chlorides. The main resluts are shown as follows:1. The synthesis of palladium NHC complexesAccording to the methods of the literature, In this dissertation, we synthesized some palladium NHC complexes with different neutral leaving ligands which had been developed. The methods are shown as follows:the imine compound2prepared from acenaphthequinone1, then the Imine2reacted with the methoxy-(methyl)chloride to get IPr(BIAN) imidazolium chloride3(Scheme1). In the addition of K2CO3, the NHC-Pd complexes6a-c could be synthesized directly by imidazolium chloride3react with PdCl2and nitrogen-containing ligands, respectively (Scheme2). The NHC-Pd complexes6d-g were prepared by the other methods. Firstly, we had to synthesize the NHC-Cu complexex as a transfer metal reagent by the imidazolium chloride3. Then we got the NHC-Pd dimers from the NHC-Cu complex. finally, we could got the NHC-Pd complexes6d-g through the dissociation of the NHC-Pd dimers(Scheme3). All of these NHC-Pd complexes6a-g had been reported by Tu’s group. In this dissertation, all of them were characterized by1H NMR、13C NMR.Ⅱ. Studies on the catalytic ability of well-defined NHC-Pd complexes in the amination of aryl chlorideIn this dissertation, the well-defind NHC-Pd complexes6a-g were regarded as precatalysts in the amination of aryl chloride(Scheme4). We screened and optimized the catalyst, base and solvent respectively. The optimal reaction conditions were: under anhydrous and anaerobic conditions, the loading of catalyst6d is0.05mol%, 1,4-dioxane as solvent, t-BuOK as base, reaction24h at80℃.Under this conditions, the well-defind NHC-Pd complexex6d could effectively catalytic the coupling reaction of a series of (hetero)aryl chlorides with secondary amines, the yield could be up to99%.Increasing the amount of catalyst to0.5mol%, the well-defind NHC-Pd complexex6d could effectively catalytic the coupling reaction of a series of aryl chlorides with primary amines. But it was failed to achieve good results for the heteroaryl chlorides.