available ketones. Mechanistic studies suggest that this Rh-catalyzed deoxygenative borylation of ketones goes through an alkene intermediate, which undergoes regiodivergent hydroboration to afford linear and branched alkylboronates. The different steric effects of PPh2Me and P(nBu)3 were found to be responsible for product selectivity by density functional theory calculations. The alkene intermediate
在这里,我们报告了一种有效的铑催化酮脱氧硼酸化合成烷基硼酸酯,其中区域选择性可以通过选择配体来切换。直链烷基硼酸酯仅在 P( n Bu) 3存在下获得,PPh 2 Me 有利于支链烷基硼酸酯的形成。该协议还允许从现成的酮中获取 1,1,2-三硼酸酯。机理研究表明,这种 Rh 催化的酮类脱氧硼酸化反应经过烯烃中间体,该中间体经历区域发散硼氢化反应,得到直链和支链烷基硼酸酯。PPh 2 Me 和 P( n Bu) 3的不同空间位阻效应通过密度泛函理论计算发现是产物选择性的原因。烯烃中间体也可以依次进行脱氢硼酸化和硼氢化反应以提供三硼酸酯。
Ni-catalyzed hydroboration and hydrosilylation of olefins with diboron and silylborane
作者:Toshiyuki Kamei、Sohshi Nishino、Toyoshi Shimada
DOI:10.1016/j.tetlet.2018.06.024
日期:2018.7
Herein we report a Ni-catalyzed formal hydroboration of olefins, which afforded anti-Markovnikov-type alkylboranes with B2pin2 and a stoichiometric amount of water. Formal hydrosilylation using air- and moisture-sensitive silylboranes also proceeded under optimized conditions. The reaction with trans-stilbene and D2O resulted in 1,2-H migration, which suggested that the reaction proceeded via β-hydride
Base-free nickel-catalyzed hydroboration of simple alkenes with bis(pinacolato)diboron in an alcoholic solvent
作者:Jiang-Fei Li、Zhen-Zhong Wei、Yong-Qiu Wang、Mengchun Ye
DOI:10.1039/c7gc02282d
日期:——
A base-free nickel-catalyzed hydroboration of unreactive simple alkenes with bis(pinacolato)diboron using methanol as the hydride source under mild conditions has been developed.
Silver-Catalyzed Hydroboration of C–X (X = C, O, N) Multiple Bonds
作者:Vipin K. Pandey、Chandra Shekhar Tiwari、Arnab Rit
DOI:10.1021/acs.orglett.1c00106
日期:2021.3.5
AgSbF6 was developed as an effective catalyst for the hydroboration of various unsaturated functionalities (nitriles, alkenes, and aldehydes). This atom-economic chemoselective protocol works effectively under low catalyst loading, base- and solvent-free moderate conditions. Importantly, this process shows excellent functional group tolerance and compatibility with structurally and electronically diverse
Cobalt-Catalyzed Hydroboration of Alkenes, Aldehydes, and Ketones
作者:Sem Raj Tamang、Deepika Bedi、Sara Shafiei-Haghighi、Cecilia R. Smith、Christian Crawford、Michael Findlater
DOI:10.1021/acs.orglett.8b02775
日期:2018.11.2
An operationally convenient and general method for hydroboration of alkenes, aldehydes, and ketones employing Co(acac)3 as a precatalyst is reported. The hydroboration of alkenes in the presence of HBpin, PPh3, and NaOtBu affords good to excellent yields with high Markovnikov selectivity with up to 97:3 branched/linear selectivity. Moreover, Co(acac)3 could be used effectively to hydroborate aldehydes
报道了使用Co(acac)3作为预催化剂对烯烃,醛和酮进行氢硼化的操作方便且通用的方法。在HBpin,PPh 3和NaO t Bu存在下,烯烃进行硼氢化可提供良好的产率,并具有高的马尔可夫尼科夫选择性和高达97:3的支链/线性选择性。而且,在温和的反应条件下,在不存在添加剂的情况下,Co(acac)3可有效地用于硼氢化醛和酮。醛基的分子间和分子内化学选择性还原发生在酮官能团之上。