Dannatt Jonathan E, Yadav Anshu, Smith Milton R, Maleczka Robert E
Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, MI, 48824-1322, USA.
Department of Chemistry, University of Dallas, 1845 East Northgate Drive, Irving, TX, 75062, USA.
Tetrahedron. 2022 Mar 12;109. doi: 10.1016/j.tet.2021.132578. Epub 2021 Nov 26.
A bidentate monoanionic ligand system was developed to enable iridium catalyzed C(sp)-H activation borylation of -methyl amides. Borylated amides were obtained in moderate to good isolated yields, and exclusive mono-borylation allowed the amide to be the limiting reagent. Selectivity for C(sp)-H activation was demonstrated in the presence of sterically available C(sp)-H bonds. Competitive kinetic isotope studies revealed a large primary isotope effect, implicating C-H activation as the rate limiting step.
开发了一种双齿单阴离子配体体系,以实现铱催化的甲基酰胺的C(sp)-H活化硼化反应。硼酸化酰胺的分离产率适中至良好,且专一的单硼化反应使酰胺成为限量试剂。在存在空间位阻可及的C(sp)-H键的情况下,证明了对C(sp)-H活化的选择性。竞争动力学同位素研究揭示了较大的一级同位素效应,表明C-H活化是速率限制步骤。