Mechanistic Study of the Palladium–Phenanthroline Catalyzed Carbonylation of Nitroarenes and Amines: Palladium–Carbonyl Intermediates and Bifunctional Effects
作者:Fabio Ragaini、Michela Gasperini、Sergio Cenini、Lucia Arnera、Alessandro Caselli、Piero Macchi、Nicola Casati
DOI:10.1002/chem.200801882
日期:2009.8.10
presence of a carboxylic or phosphorus acid is first‐order with respect to complex, acid, and toluidine. A CO atmosphere is also required for the reaction to proceed. Acid dimerization was shown not to be influential under the concentration conditions examined, but reaction between the acid and toluidine is not negligible and a correction has to be applied. Diphenylphosphinic acid is more effective than
钯-菲咯啉配合物催化硝基芳烃羰基化反应和胺氧化羰基化反应,根据条件产生氨基甲酸酯和脲。有证据表明,这两个过程的关键步骤是胺羰基化。在这里,我们表明当反应在甲醇中进行时,关键中间体化合物具有通式 [Pd(RPhen)(COOMe) 2 ] ( 1 )(RPhen=1,10-菲咯啉或其取代衍生物之一)。1的反应动力学在羧酸或磷酸存在下与甲苯胺的反应相对于络合物、酸和甲苯胺来说是一阶的。反应进行也需要CO气氛。酸二聚显示在所检查的浓度条件下没有影响,但酸和甲苯胺之间的反应不可忽略,必须进行校正。在催化条件下也观察到,二苯基次膦酸在促进该反应方面比任何羧酸都更有效。一系列平衡和不可逆的酸辅助质子转移解释了观察到的数据。当 RPhen=2,9-Me 2时,光谱观察到1类配合物与 CO 形成加合物芬。还对几种类似的配合物进行了光谱表征,并解析了 [Pd(2,9-Me 2 Phen)Cl 2 (CO)]的