Studies On The Synthesis Of Amides Via Palladium-catalyzed Carbonylation Reactions

Transition-metal catalyzed carbonylation reaction has become an important means to construct carbonyl compounds, in which palladium is one of the most rapidly developing metal. Amides and its derivatives are a kind of important industrial raw material and an important intermediate in organic synthesis. Traditional synthesis methods of amide have many shortcomings, such as the cumbersome reaction procedures, the application of highly toxic raw material, the serious environmental pollution, the harsh reaction condition, the low yield of production, and so on. Owing to the concept of green chemistry, traditional synthesis methods are gradually replaced by transition-metal catalyzed carbonylation for synthesis of amides, in which palladium exhibited excellent catalytic performance, such as high catalytic efficient, high selectivity and yield, mild reaction condition and so on. In this thesis, we explore the synthesis of amides by the method of palladium-catalyzed carbonylation, the main contents are as follows:1. An efficient homogeneous catalytic system was explored for the aminocarbonylation reaction of aryl iodides for synthesis of amides at low temperature and atmospheric pressure for the first time. After the screening of ligand, promoter, solvent, reaction temperature and dosage of catalyst, the optimal reaction condition was attained to be 5mol% Pd(PtBu3)2, 1.0equiv. NH4 Cl as promoter, 1.0equiv. N,N- diisopropylethylamine as base, acetonitrile as solvent, CO balloon, 60°C for 18 h. This catalytic system possessed a good universality for the aminocarbonylation reaction of aryl iodides containing different substituents(involving a case of 3-bromopyridine) with organic amines, that the yields of corresponding amides were excellent. And it‘s very significant to present this catalytic system for the synthesis of amides by aminocarbonylation of aryl iodide at low temperature and atmospheric pressure for the first time.2. Based on our previous study on Pd catalyst, we further explored the catalytic activity of heterogeneous catalyst Pd Cl2(phen)@Y and Pd2+@Y for the carbonylation of trimethylamine. The influence of the dosage of Palladium on reaction activity was discussed. When Pd2+@Y was chosen as the catalyst with a low palladium loadings(1.3 mol%), the yield could be up to 93% at 200°C, 5.0MPa for 5h. And for the recycle test ofPd2+@Y catalyst, the yield of N, N- dimethylacetamide maintained at 90% after the catalyst was reused 6 times, which exhibited a good cycle performance. The experiment will contribute to its industrialization.