Kinetically-Controlled Ni-Catalyzed Direct Carboxylation of Unactivated Secondary Alkyl Bromides without Chain Walking
作者:Jacob Davies、Julien R. Lyonnet、Bjørn Carvalho、Basudev Sahoo、Craig S. Day、Francisco Juliá-Hernández、Yaya Duan、Álvaro Velasco-Rubio、Marc Obst、Per-Ola Norrby、Kathrin H. Hopmann、Ruben Martin
DOI:10.1021/jacs.3c11205
日期:2024.1.24
Herein, we report the direct carboxylation of unactivated secondary alkyl bromides enabled by the merger of photoredox and nickel catalysis, a previously inaccessible endeavor in the carboxylation arena. Site-selectivity is dictated by a kinetically controlled insertion of CO2 at the initial C(sp3)–Br site by the rapid formation of Ni(I)–alkyl species, thus avoiding undesired β-hydride elimination
在此,我们报道了光氧化还原和镍催化合并实现的未活化仲烷基溴的直接羧化,这是以前在羧化领域无法企及的努力。位点选择性是由 Ni(I)-烷基物质的快速形成在初始 C(sp3)-Br 位点的动力学控制插入 CO2 决定的,从而避免了不需要的 β-氢化物消除和链式行走过程。初步的机理实验揭示了立体电子效应在引导反应性和位点选择性方面的微妙之处。