regioselective ring-opening reaction of epoxides with various carboxylicacids under metal-free conditions is reported. The ring-opening of epoxides takes place in the presence of graphite oxide as an efficient and available catalyst to produce the corresponding 2-hydroxy monoester and 1,2-diester derivatives in good yields. Regioselective attack of the nucleophile, short reaction times, metal-free conditions
A Convenient Synthesis of Glycidyl Esters (2,3-Epoxypropyl Alkanoates)
作者:Junzo Otera、Shinjiro Matsuzaki
DOI:10.1055/s-1986-31856
日期:——
A novel method for synthesizing glycidyl esters (2,3-epoxypropyl alkanoates) 1 has been achieved by the sequence of the organotin phosphate catalyzed reaction of epichlorohydrin 2 with carboxylic acids and dehydrochlorination of the resulting mixture of ester chlorohydrins 3 + 4 followed by separation.
Finding the right balance between tertiary amine steric effect and solvent polarity for the regioselectivity and kinetics of epichlorohydrin acetolysis
作者:Kseniia Yutilova、Anastasiia Tkach、Vladislav Tarasenko、Elena Shved
DOI:10.1002/poc.4573
日期:2024.1
asymmetric oxirane ring-openingreaction leading to the formation of regioisomeric chlorohydrin esters was studied in the reactionseries “acetic acid–epichlorohydrin–tetrahydrofuran (nitrobenzene)–trialkylamine” by kinetic methods and FT-IR spectroscopy. The effect of solvent polarity and the structure of tertiary amines on the regioselectivity and reaction rate were studied. Tertiary amines with comparable
通过动力学方法和 FT-IR 光谱研究了反应系列“乙酸-环氧氯丙烷-四氢呋喃(硝基苯)-三烷基胺”中导致形成区域异构氯醇酯的不对称环氧乙烷开环反应。研究了溶剂极性和叔胺结构对区域选择性和反应速率的影响。选择碱度相当但亲核性和空间结构不同的叔胺作为催化剂。结果表明,在不同极性的溶剂中,初始反应体系的组分既以氢键配合物的形式存在,也以单独的物质的形式存在。建立了酸和胺在不同极性溶剂中的反应级数。建立了反应速率与胺的亲核性和结构以及溶剂的极性参数之间的相关性。使用区域异构反应产物的比例通过1 H NMR 光谱研究了反应的区域选择性。结果表明,叔胺的结构和溶剂的极性有效控制环氧氯丙烷催化乙酰解的区域选择性和速率。详细描述了反应区域流的方案。
FeCl 3 /pyridine: dual-activation in opening of epoxide with carboxylic acid under solvent free condition
Inexpensive, non-toxic, and readily available catalyst system FeCl3/pyridine was found to be highly efficient for the opening of a wide variety of epoxides with carboxylic acid under solvent free conditions. (C) 2013 Elsevier Ltd. All rights reserved.
Regioselectivity of the acidolysis of 2-(chloromethyl)oxirane with aromatic acids in the presence of organic bases
作者:M. A. Sinel’nikova、E. N. Shved
DOI:10.1134/s107042801403004x
日期:2014.3
Regioselectivity of the reaction of 2-(chloromethyl)oxirane with aromatic acids in the presence of tertiary amines and tetraalkylammonium halides has been studied. Opening of the oxirane ring follows simultaneously S(N)2 and borderline S(N)2 mechanisms. The regioselectivity of the acidolysis of substituted oxiranes is determined by acid-base properties of the reactants and catalysts and steric factor. The regioselectivity increases as the contribution of the S(N)2 mechanism increases.