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。
Manganese-Catalyzed Borylation of Unactivated Alkyl Chlorides
作者:Thomas C. Atack、Silas P. Cook
DOI:10.1021/jacs.6b03157
日期:2016.5.18
of (bis)pinacolatodiboron with a wide range of alkyl halides, demonstrating the first manganese-catalyzed coupling with alkyl electrophiles. This method allows access to primary, secondary, and tertiary boronic esters from the parent chlorides, which were previously inaccessible as coupling partners. The reaction proceeds in high yield with as little as 1000 ppm catalyst loading, while 5 mol % can
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.
Iron-Catalyzed Hydroboration: Unlocking Reactivity through Ligand Modulation
作者:Maialen Espinal-Viguri、Callum R. Woof、Ruth L. Webster
DOI:10.1002/chem.201602818
日期:2016.8.8
hydroboration (HB) of alkenes and alkynes is reported. A simple change in ligand structure leads to an extensive change in catalyst activity. Reactions proceed efficiently over a wide range of challenging substrates including activated, unactivated and sterically encumbered motifs. Conditions are mild and do not require the use of reducing agents or other additives. Large excesses of borating reagent are not required