铱催化邻碳硼烷通过直接B-H活化实现区域选择性B(3)-烯基化/B(3,6)-二烯基化反应
Iridium-Catalyzed Regioselective B(3)-Alkenylation/B(3,6)-Dialkenylation of o-Carboranes by Direct B-H Activation.
作者信息
Cheng Ruofei, Qiu Zaozao, Xie Zuowei
机构信息
Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, University of, Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, P. R. China.
CAS Key Laboratory of Energy Regulation Materials, Shanghai Institute of Organic Chemistry, Chinese Academy of, Sciences, 345 Lingling Rd, Shanghai, 200032, P. R. China.
出版信息
Chemistry. 2020 Jun 5;26(32):7212-7218. doi: 10.1002/chem.202000549. Epub 2020 Mar 20.
Iridium-catalyzed formal alkyne hydroboration with cage B-H of o-carborane has been achieved, leading to the controlled synthesis of a series of 3,6-[trans-(AlkCH=CH)] -o-carboranes (Alk=alkyl), 3-cis-(ArCH=CH)-o-carboranes (Ar=aryl), and 3-cis-(ArCH=CH)-6-trans-(AlkCH=CH)-o-carboranes in high yields with excellent regio- and very good cis-trans selectivity. The most electron-deficient B(3,6)-H vertices favor oxidative addition on electron-rich metal centers, which is responsible for the regioselectivity. On the other hand, the configuration of the resultant olefinic units is dominated by alkyne substituents. Alkyl groups lead to a trans-configuration whereas bulky aryl substitutions result in cis-configuration.
已实现铱催化邻碳硼烷的笼状B-H与炔烃进行形式上的硼氢化反应，从而能够以高收率、优异的区域选择性和非常好的顺反选择性，可控地合成一系列3,6-[反式-(AlkCH=CH)]-邻碳硼烷（Alk = 烷基）、3-顺式-(ArCH=CH)-邻碳硼烷（Ar = 芳基）以及3-顺式-(ArCH=CH)-6-反式-(AlkCH=CH)-邻碳硼烷。电子缺乏程度最高的B(3,6)-H顶点有利于在富电子金属中心上进行氧化加成，这是区域选择性的原因。另一方面，所得烯烃单元的构型由炔烃取代基主导。烷基导致反式构型，而庞大的芳基取代则产生顺式构型。
Zotero 插件