Umpolung Reactivity of Aldehydes toward Carbon Dioxide
作者:Martin Juhl、Ji-Woong Lee
DOI:10.1002/anie.201806569
日期:2018.9.17
Carbondioxide is an intrinsically stable molecule. Therefore, its activation requires extra energy input in the form of reactive reagents and/or activated catalysts and, often, harsh reaction conditions. Reported here is a direct carboxylation reaction of aromatic aldehydes with carbondioxide to afford α‐keto acids as added‐value products. In situ generation of a reactive cyanohydrin was the key
二氧化碳是本质上稳定的分子。因此,其活化需要以反应性试剂和/或活化的催化剂的形式以及通常苛刻的反应条件的形式输入额外的能量。此处报道的是芳香醛与二氧化碳的直接羧化反应,以提供α-酮酸作为增值产品。在操作温和的反应条件下(25–40°C,1 atm CO 2),原位生成反应性氰醇是成功进行羧化反应的关键。所得的α-酮酸可作为还原性胺化反应合成α-氨基酸的平台,说明了从二氧化碳化学合成基本生物活性分子的过程。
Tri-lacunary polyoxometalates of Na8H[PW9O34] as heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation and the synthesis of benzoxazole derivatives
作者:Shen Zhao、Yang Chen、Yu-Fei Song
DOI:10.1016/j.apcata.2014.01.017
日期:2014.4
development of tri-lacunary polyoxometalates (POMs) of Na8H[A-PW9O34]·7H2O and Na8H[B-PW9O34]·19H2O (Na-A-PW9 and Na-B-PW9) as highlyselective and efficient heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation of various aldehydes and ketones and the synthesis of benzoxazole derivatives at 25 °C under mild conditions. Since both Na-A-PW9 and Na-B-PW9 display no characteristic porosity
TBD-catalyzed cyanosilylation of aldehydes and ketones
作者:S. Matsukawa、J. Kimura
DOI:10.1080/00397911.2016.1241884
日期:2016.12.1
This study examines the catalytic efficacy of 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) in the cyanosilylation of aldehydes and ketones. In an aldehyde reaction, the corresponding products were obtained at high yield using minimal TBD (0.01 mol%). TBD was similarly effective in various ketone reactions. GRAPHICAL ABSTRACT
Activation of trimethylsilyl cyanide by potassium phthalimide for facile synthesis of TMS-protected cyanohydrins
作者:Mohammad G. Dekamin、Zahra Karimi
DOI:10.1016/j.jorganchem.2009.01.058
日期:2009.5
Potassium phthalimide was found to be a highly effective and easily accessible organocatalyst for the cyanosilylation of various carbonyl compounds under extremely mild conditions. The corresponding cyanohydrintrimethylsilylethers were obtained in high to quantitative yields in solvent-freeconditions at room temperature using 2.5 mol% catalyst loading.
Organocatalytic synthesis of cyanohydrin trimethylsilyl ethers by potassium 4-benzylpiperidinedithiocarbamate under solvent-free conditions
作者:Mohammad G. Dekamin、Roghieh Alizadeh、M. Reza Naimi-Jamal
DOI:10.1002/aoc.1600
日期:2010.3
Potassium 4‐benzylpiperidinedithiocarbamate was found to be an efficient organocatalyst for facile addition of trimethylsilyl cyanide to a wide variety of aldehydes and ketones to afford corresponding cyanohydrintrimethylsilylethers in high to quantitative yields. The reaction proceeded smoothly by employing 2.0 mol% PBPDC loading under mild conditions at room temperature within a very short reaction