A simple and efficient <i>in situ</i> generated copper nanocatalyst for stereoselective semihydrogenation of alkynes
作者:Byoung Yong Park、Taeho Lim、Min Su Han
DOI:10.1039/d1cc02685b
日期:——
aryl–alkyl, and aliphatic alkynes were selectively reduced to (Z)-alkenes affording up to 99% isolated yield. The semihydrogenation of terminal alkynes to alkenes and gram-scale applications were also reported. In addition to eliminating catalystpreparation, the proposed approach is simple and practical and serves as a suitable alternative method to the conventional Lindlar catalyst.
开发一种简单、有效且实用的 ( Z ) 炔烃选择性半氢化方法被认为是有机实验室规模易于获得的应用所必需的。在本文中,炔烃的( Z )-选择性半氢化反应是使用铜纳米催化剂实现的,该催化剂通过将氨硼烷添加到硫酸铜的乙醇溶液中而原位生成。不同类型的炔烃,包括芳基-芳基、芳基-烷基和脂肪族炔烃被选择性地还原为 ( Z)-烯烃的分离产率高达 99%。还报道了末端炔烃半氢化成烯烃和克级应用。除了不需要催化剂制备外,所提出的方法简单实用,可作为传统 Lindlar 催化剂的合适替代方法。
General and Chemoselective Copper Oxide Catalysts for Hydrogenation Reactions
Copper oxidecatalysts have been prepared by pyrolysis of copper acetate on aluminum oxide. The material resulting from pyrolysis at 800 °C allows for catalytic hydrogenations at low temperature of a variety of unsaturated compounds such as quinolines, alkynes, ketones, imines, and polycyclic aromatic hydrocarbons as well as nitroarenes with good activity and selectivity.
N-graphitic-modified cobalt nanoparticles (Co/[email protected]2-800) are shown to be active in the semihydrogenation of alkynes to alkenes. Key to success for efficient catalysis is both the modification of the metal nanoparticles by nitrogen-doped graphitic layers and the use of silica as support. Several internal alkynes are converted to the Z isomer in high yields with up to 93% selectivity. In addition, a
Monodisperse nickel-nanoparticles for stereo- and chemoselective hydrogenation of alkynes to alkenes
作者:Kathiravan Murugesan、Ahmad S. Alshammari、Manzar Sohail、Matthias Beller、Rajenahally V. Jagadeesh
DOI:10.1016/j.jcat.2018.12.018
日期:2019.2
Here, we report the use of monosaccharides for the preparation of novel nickel nanoparticles (NP), which constitute selective hydrogenation catalysts. For example, immobilization of fructose and Ni(OAc)2 on silica and subsequent pyrolysis under inert atmosphere produced graphitic shells encapsulated Ni-NP with uniform size and distribution. Interestingly, fructose acts as structure controlling compound
Stereodivergent Alkyne Reduction by using Water as the Hydrogen Source
作者:Santhosh Rao、Kandikere Ramaiah Prabhu
DOI:10.1002/chem.201803147
日期:2018.9.18
homogeneous Pd‐catalyzed stereodivergent reduction of alkynes to Z and E alkenes by using H2O as the H2 source is presented. Mediated by a diboron reagent, the transfer hydrogenation has been accomplished to yield the desired geometrical isomer by rational ligand selection. The switchable stereoselectivity achieved using simple phosphine ligands is generally excellent. D2O has also been used as a D2 source