Ni–O Cooperation versus Nickel(II) Hydride in Catalytic Hydroboration of <i>N</i>-Heteroarenes
作者:Jianguo Liu、Jia-Yi Chen、Mengjing Jia、Bangrong Ming、Jiong Jia、Rong-Zhen Liao、Chen-Ho Tung、Wenguang Wang
DOI:10.1021/acscatal.8b05136
日期:2019.5.3
An air-stable half-sandwich nickel(II) complex bearing a phosphinophenolato ligand, Cp*Ni(1,2-Ph2PC6H4O) (1), has been designed and synthesized for activation of HBpin and catalytic hydroboration of N-heteroarenes such as pyridine. Through addition of the H–B bond across the Ni–O bond, 1 reacts with HBpin to afford an 18-electron Ni(II)–H intermediate [H1(Bpin)] featuring an oxygen-stabilized boron
设计并合成了具有膦基酚基配体Cp * Ni(1,2-Ph 2 PC 6 H 4 O)(1)的空气稳定的半三明治镍(II)配合物。N-杂芳烃,例如吡啶。通过跨Ni-O键添加H-B键,1与HBpin反应,得到18电子Ni(II)-H中间体[H 1((Bpin)]的特征在于氧稳定的硼部分,其易于还原吡啶类似物以得到1,2-硼氢化产物,从而在温和条件下完成催化循环。1和Cp * NiH(PPh 3)(3 H)在催化硼氢化反应中的活性存在明显差异,从而证明了膦基酚基配体传递硼基的必要性。后者缺乏功能性氧原子,并且对于催化过程是惰性的。