已经证明了使用甲硅烷基硼酸盐和 B 2 pin 2通过吡啶介导的 B 元素间活化对烯烃进行无金属甲硅烷基吡啶基化,这为各种 C 4甲硅烷基烷基化吡啶提供了实用的策略。DFT 计算和控制实验表明,反应通过甲硅烷基自由基加成/自由基-自由基偶联顺序进行。该协议具有广泛的底物范围和优异的官能团兼容性,因此在生物活性分子的后期修饰中展示了巨大的潜力。
Direct Enamido C(sp<sup>2</sup>)−H Diphosphorylation Enabled by a PCET‐Triggered Double Radical Relay: Access to<i>gem</i>‐Bisphosphonates
作者:Hao‐Qiang Cao、Hao‐Nan Liu、Zhe‐Yuan Liu、Bao‐Kun Qiao、Fa‐Guang Zhang、Jun‐An Ma
DOI:10.1002/chem.202000517
日期:2020.4.24
electron-transfer (PCET)-triggered enamidoC(sp2 )-Hdiphosphorylation. This reaction represents a rare example of realizing the challenging double C-P bond formation at a single carbon atom, thus providing facile access to a broad variety of structurally diverse bisphosphonates from simple enamides under silver-mediated conditions. Initial mechanistic studies demonstrated that the diphosphorylation involves
π-Lewis basic palladium (0) catalysis, delivering benzofuran-fused eight-membered heterocycles in high efficiency, regio- and enantioselectivities. Highly diastereoselective derivatizations of the resultant eight-membered cyclic alkenes provide a facile access to diverse fused polycyclic compounds in excellent efficiency.