Cui Xin, Li Zhe, Tao Chuan-Zhou, Xu Yu, Li Juan, Liu Lei, Guo Qing-Xiang
Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
Org Lett. 2006 Jun 8;8(12):2467-70. doi: 10.1021/ol060585n.
N,N-Dimethyl-beta-alanine was found to be a more powerful phosphine-free ligand than the previously reported ligand, N,N-dimethylglycine, in the Pd-catalyzed Heck reaction for a variety of aryl bromides, aryl iodides, and activated aryl chlorides with a practical turnover number of 10(3). Both kinetic and theoretical studies suggested that N,N-dimethyl-beta-alanine led to faster oxidative addition of an aryl halide to Pd than N,N-dimethylglycine. [reaction: see text]
在钯催化的Heck反应中,对于多种芳基溴化物、芳基碘化物和活性芳基氯化物而言,发现N,N-二甲基-β-丙氨酸是一种比先前报道的配体N,N-二甲基甘氨酸更强有力的无膦配体,实际周转数为10³。动力学和理论研究均表明,与N,N-二甲基甘氨酸相比,N,N-二甲基-β-丙氨酸能使芳基卤化物向钯的氧化加成更快。[反应:见正文]