On the mechanism of Ni(<scp>ii</scp>)-promoted Michael-type hydroamination of acrylonitrile and its substituted derivatives
作者:S. Lapointe、D. Zargarian
DOI:10.1039/c6dt02105k
日期:——
hydroamination of acrylonitrile and its substituted derivatives promoted by Ni(II) complexes is believed to proceed via an outer-sphere nucleophilic attack on the cationic adduct of the nitrile-coordinated substrate. As a test for the validity of this mechanistic postulate, we have sought to establish a correlation between the electrophilic character of the Ni(II) center and the degree to which it can
Ni(II)配合物促进的丙烯腈及其取代衍生物的迈克尔型加氢胺被认为是通过外球亲核攻击腈配位的底物的阳离子加合物而进行的。作为对该机械假设的有效性的测试,我们试图在Ni(II)中心的亲电子特性与其可以激活底物对胺类进行亲核攻击的程度之间建立相关性。通过筛选阳离子乙腈加合物[(R-POCOP)Ni(NCCH 3)] [OSO 2 CF 3]轴承供电子性或配体POCOP(R-POCOP =κ的中心芳环上的吸电子取代基R P,κ Ç,κ P -2,6-(I-PR 2 PO)2 -4- RC 6 H 2; R = OMe(3),COOMe(4))。发现将伯胺添加到巴豆腈,甲基丙烯腈和肉桂腈中的催化活性取决于所用的前体和胺以及反应时间。这些研究得到配体交换研究的补充,该研究确定了典型氢化胺化混合物主要成分之间的相对结合顺序(RCN>胺> OSO 2 CF3),因此支持阳离子腈加合物构成催化歧管中的静止