Murphy Jaclyn M, Lawrence Joshua D, Kawamura Kazumori, Incarvito Christopher, Hartwig John F
Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, USA.
J Am Chem Soc. 2006 Oct 25;128(42):13684-5. doi: 10.1021/ja064092p.
We report the regiospecific, ruthenium-catalyzed borylation of saturated terminal C-H bonds. Alkylboronates were obtained in 78-98% yields. The borylations of alkanes, trialkylamines, protected alcohols, and fluoroalkanes occurred regiospecifically at the methyl group that is least sterically hindered. 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 methyl group that is least sterically hindered and most electron-deficient. Ruthenium compounds containing boryl ligands were synthesized, and one was characterized by X-ray crystallography. One of these compounds contained a rare bridging boryl ligand and served as a catalyst precursor for the borylation of octane.
我们报道了饱和末端C-H键的区域特异性钌催化硼化反应。硼酸烷基酯的产率为78-98%。烷烃、三烷基胺、保护醇和氟代烷烃的硼化反应区域特异性地发生在空间位阻最小的甲基上。与大多数有机金属C-H活化反应不同，烷烃的反应产率高于芳烃的反应。进行了探究空间和电子效应的烷基硼化反应。这些反应表明，硼化反应优先发生在空间位阻最小且电子缺乏最多的甲基上。合成了含硼基配体的钌化合物，其中一种通过X射线晶体学进行了表征。这些化合物之一含有罕见的桥连硼基配体，并用作辛烷硼化反应的催化剂前体。
