Understanding Ni(II)-Mediated C(sp<sup>3</sup>)–H Activation: Tertiary Ureas as Model Substrates
作者:D. Dawson Beattie、Anna C. Grunwald、Thibaut Perse、Laurel L. Schafer、Jennifer A. Love
DOI:10.1021/jacs.8b07708
日期:2018.10.3
study of C(sp3)-H bond activation mediated by nickel. Cyclometalated Ni(II) ureate [(PEt3)Ni(κ3- C,N,N-(CH2)N(Cy)(CO)N((N)-quinolin-8-yl))] was synthesized and isolated from the urea precursor, (Me)(Cy)N(CO)N(H)(quinolin-8-yl), via C(sp3)-H activation. We investigated the effects of solvents and base additives on the rate of C-H activation. Kinetic isotope effect experiments showed that C-H activation
我们报告了镍介导的 C(sp3)-H 键活化的机理研究。环金属化 Ni(II) 脲酸酯 [(PEt3)Ni(κ3-C,N,N-(CH2)N(Cy)(CO)N((N)-quinolin-8-yl))]尿素前体 (Me)(Cy)N(CO)N(H)(quinolin-8-yl),通过 C(sp3)-H 活化。我们研究了溶剂和碱添加剂对 CH 活化速率的影响。动力学同位素效应实验表明 CH 活化是速率决定性的。通过氘标记和质子化研究,我们还表明 CH 活化是可逆的。我们将此反应扩展到一系列具有初级和次级 C(sp3)-H 键的尿素,它们很容易激活以形成类似的镍化产物。最后,我们表明羧酸盐添加剂有助于配体解离和初始 NH 键活化,