1-苯基-3-甲基-4-苯甲酰基吡唑啉酮/PdCl_2在温和条件下催化Suzuki偶联反应的研究

4-Benzoyl-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one / PdCl_2-Catalyzed Suzuki Coupling Reactions under Mild Aerobic Conditions

考察了商品化的简单非膦配体1-苯基-3-甲基-4-苯甲酰基吡唑啉酮在有氧温和条件下的Suzuki偶联反应活性,探讨了反应温度、反应时间、溶剂以及碱对反应的影响。结果表明,该配体在优化的反应条件下能高效催化不同溴代反应物和氯代反应物与苯硼酸的交叉偶联反应;提高反应温度、延长反应时间和引入质子性极性有机/水混合溶剂有利于偶联反应的进行。

A simple commercial ligand 4-benzoyl-3-methyl-l-phenyl-lH-pyrazol-5 （4H）-one has been applied to the palladium-catalyzed Suzuki-Miyaura cross-coupling in this paper. The effect of reaction condition, such as temperature, time, solvents and bases on the yield of product has been evaluated. Under the optimized conditions, a variety of aryl bromides and phenylboronic acid were successfully cross-coupled in high yield at a low catalytic loading of 0. 1 （mol） %. Furthermore, the less reactive reactants such as aryl chlorides was explored to enlarge the scope of this cross-coupling, and it was found that the catalytic system employing the ligand in DMF/H20 provided a general and convenient method to prepare biaryls from activated aryl chlorides. Besides, the optimal experiments revealed that the improvement of reaction time/temperature as well as the polarity of the proton solvent turned out to be the effective method for the coupling reaction.