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。
Atom-efficient regioselective 1,2-dearomatization of functionalized pyridines by an earth-abundant organolanthanide catalyst
作者:Alexander S. Dudnik、Victoria L. Weidner、Alessandro Motta、Massimiliano Delferro、Tobin J. Marks
DOI:10.1038/nchem.2087
日期:2014.12
synthesis. Dearomatization of pyridine derivatives is an important transformation to access a wide range of valuable nitrogenous natural products, pharmaceuticals and materials. Here, we report an efficient 1,2-regioselective organolanthanide-catalysed pyridine dearomatization process using pinacolborane, which is compatible with a broad range of pyridines and functional groups and employs equimolar
Manganese‐Catalyzed Hydroborations with Broad Scope
作者:Pradip Ghosh、Axel Jacobi von Wangelin
DOI:10.1002/anie.202103550
日期:2021.7.12
synthetic manipulation and chemical valorization. The applications of catalytic hydrofunctionalization benefit from the use of liquid reducing agents and operationally facile setups. Metal-catalyzed hydroborations provide a highly prolific platform for reductive valorizations of stable C=X electrophiles. Here, we report an especially facile, broad-scope reduction of various functions including carbonyls
Iron-Catalyzed 1,2-Selective Hydroboration of <i>N</i>-Heteroarenes
作者:Fanjun Zhang、Heng Song、Xuewen Zhuang、Chen-Ho Tung、Wenguang Wang
DOI:10.1021/jacs.7b11416
日期:2017.12.13
A N2-bridged diiron complex [Cp*(Ph2PC6H4S)Fe]2(μ-N2) (1) has been found to catalyze the hydroboration of N-heteroarenes with pinacolborane, giving N-borylated 1,2-reduced products with high regioselectivity. The catalysis is initiated by coordination of N-heteroarenes to the iron center, while the B-H bond cleavage is the rate-determining step.