Regiospecific opening of 1,2-expoxides with acetone cyanohydrin under mildly basic conditions
作者:David Mitchell、Thomas M Koenig
DOI:10.1016/s0040-4039(00)92067-7
日期:1992.6
Acetone cyanohydrin with stoichiometic triethylamine opens epoxides regiospecifically to give β-hydroxy nitriles. As expected, addition of cyanide occurs at the least substituted carbon.
The lipase mediated kinetic resolution of pharmaceutically important beta-hydroxy nitrites is described in high enantionteric excesses and good yields. Some of the chiral beta-hydroxy nitriles have been employed in the synthesis of P-adrenergic blocking agents such as propranolol, alprenolol and moprolol. This protocol has also been extended for the enantiopure preparation of 5-(4-tosyloxymethyl)-1,3-oxazolidine-2-one and 3-liydroxy-4-tosyloxybutaiieiiitrile, chiral intermediates of high synthetic value. (c) 2005 Elsevier Ltd. All rights reserved.
Greener and regioselective ring opening of epoxides with TMSCN using potassium salts of magnetic carbon nitride
作者:Mostafa Saadat、Mahnaz Qomi、Najmedin Azizi
DOI:10.1007/s00706-020-02689-0
日期:2020.10
green and recyclable catalyst for rapid and regioselective ring opening of epoxides with TMSCN, yielding the β-hydroxynitrile ring-opened products undermild reaction conditions. It is manageable to large-scale preparation with simple instruments and gives the desired compounds in short reaction times with good-to-excellent yields (73–95%) undersolvent-freeconditions. Magnetic separation protocol has
摘要 磁性石墨碳氮化碳(Fe 3 O 4 @gC 3 N 4 -K)的钾盐经合成,被证明是一种绿色且可回收的催化剂,可用于通过TMSCN快速和区域选择性地使环氧化物开环,生成β-羟基腈开环产物在温和的反应条件下。使用简单的仪器即可进行大规模制备,并且在无溶剂条件下以较短的反应时间即可获得所需化合物,并具有良好至优异的收率(73–95%)。磁分离方案已使用外部磁体实现了从未纯化的反应混合物中简单分离和重复使用催化剂,而在五个循环后没有损失催化操作。 图形摘要
FAURAN C.; DOUZON C., EUR. J. MED. CHEM., 1976, 11, NO 1, 73-74