Nickel‐Catalyzed Asymmetric Hydrogenation of
<i>N</i>
‐Sulfonyl Imines
作者:Bowen Li、Jianzhong Chen、Zhenfeng Zhang、Ilya D. Gridnev、Wanbin Zhang
DOI:10.1002/anie.201902576
日期:2019.5.27
An efficient nickel‐catalyzed asymmetric hydrogenation of N‐tBu‐sulfonyl imines was developed with excellent yields and enantioselectivities using (R,R)‐QuinoxP* as a chiral ligand. The use of a much lower catalyst loading (0.0095 mol %, S/C=10500) represents the highest catalytic activity for the Ni‐catalyzed asymmetric hydrogenations reported so far. Mechanistic studies suggest that a coordination
一种有效的镍催化的不对称氢化ñ -吨卜-磺酰亚胺是使用具有优良的产率和对映选择性显影([R ,- [R)-作为手性配体的QuinoxP *。使用低得多的催化剂负载量(0.0095 mol%,S / C = 10500)代表了迄今为止报道的Ni催化不对称氢化的最高催化活性。机理研究表明,镍盐及其配合物之间存在配位平衡,过量的镍盐会促进活性镍配合物的形成,因此提高了氢化效率。还通过计算研究了催化循环,以确定对映选择性的来源。发现在过渡态的催化剂和底物之间存在大量的弱吸引作用的广泛网络,这也可能有助于高催化活性。