Ruthenium-Catalyzed Regiospecific Borylation of Methyl C−H Bonds
作者:Jaclyn M. Murphy、Joshua D. Lawrence、Kazumori Kawamura、Christopher Incarvito、John F. Hartwig
DOI:10.1021/ja064092p
日期:2006.10.1
the methylgroup that is least stericallyhindered. In contrast to most organometallic C-H activation, the reactions of alkanes occurred in higher yields than the reactions of arenes. Reactions were conducted that probed steric and electronic effects on the alkyl borylation. These reactions showed that the borylation occurred preferentially at the methylgroup that is least stericallyhindered and
我们报告了饱和末端 CH 键的区域特异性、钌催化硼化。以78-98%的产率获得烷基硼酸酯。烷烃、三烷基胺、受保护的醇和氟烷烃的硼酸化发生在空间位阻最小的甲基上。与大多数有机金属 CH 活化相反,烷烃反应的产率高于芳烃反应。进行反应以探测对烷基硼化的空间和电子效应。这些反应表明硼酸化优先发生在空间位阻最小和最缺电子的甲基。合成了含有硼基配体的钌化合物,并通过 X 射线晶体学表征了一种。
Photoinduced Radical Borylation of Alkyl Bromides Catalyzed by 4‐Phenylpyridine
作者:Li Zhang、Zhong‐Qian Wu、Lei Jiao
DOI:10.1002/anie.201912564
日期:2020.1.27
Utilizing pyridine catalysis, we developed a visible-light-induced transition-metal-free radical borylation reaction of unactivated alkyl bromides that features a broad substrate scope and mild reaction conditions. Mechanistic studies revealed a novel nucleophilic substitution/photoinduced radical formation pathway, which could be utilized to trigger a variety of radical processes.
A metal‐free radical borylation of alkyl and aryl iodides with bis(catecholato)diboron (B2cat2) as the boron source under mild conditions is introduced. The borylation reaction is operationally easy to conduct and shows high functional group tolerance and broad substrate scope. Radical clock experiments and density functional theory calculations provide insights into the mechanism and rate constants
介绍了在温和条件下以双(儿茶酚)二硼(B 2 cat 2 )作为硼源对烷基碘化物和芳基碘化物进行金属自由基硼化反应。硼化反应操作简便,具有较高的官能团耐受性和广泛的底物范围。自由基时钟实验和密度泛函理论计算提供了对 B 2 cat 2的 C 自由基硼化的机制和速率常数的见解。
Regiospecific Functionalization of Methyl C−H Bonds of Alkyl Groups in Reagents with Heteroatom Functionality
作者:Joshua D. Lawrence、Makoto Takahashi、Chulsung Bae、John F. Hartwig
DOI:10.1021/ja044933x
日期:2004.12.1
rhodium-catalyzed borylation of saturated terminal C-H bonds in molecules with existing functionality. Moderate to good yields were obtained with the organic substrate in excess and as limiting reagent. The borylations of trialkylamines, protected alcohols, protected ketones, and fluoroalkanes occurred regiospecifically at the methyl group that is least sterically hindered. Reactions were also conducted that probed