作者:Kazutoshi Funahashi
DOI:10.1246/bcsj.52.1488
日期:1979.5
Oxiranes reacted with aryl esters in the presence of base. The reactions of aryl carboxylates with alkyloxiranes afforded almost exclusively 1-alkyl-2-(aryloxy) ethyl carboxylates, whereas the reactions with aryloxiranes gave a mixture of 1-aryl-2-(aryloxy) ethyl carboxylates and 2-aryl-2-(aryloxy) ethyl carboxylates. Similar results were also obtained in the reaction with S-aryl thiocarboxylates and diaryl carbonates. The rate of reaction between phenyl acetate and phenoxymethyloxirane (PMO) in the presence of tributylamine (n-Bu3N) as a catalyst has been determined in the temperature range 110 to 130 °C and may be expressed by –d[PMO]⁄dt=k2[n-Bu3N]·[PMO]. The apparent activation energy calculated from the Arrhenius plots is 85.8 kj/mol. The reaction catalyzed by tributylamine is assumed to proceed through zwitter ions, n-Bu3\overset+NCH2CH(R)O− and n-Bu3\overset+NCH(R)CH2O−, which attack aryl carboxylate.
在碱存在下,环氧乙烷与芳基酯反应。烷基环氧乙烷与芳基羧酸酯的反应主要生成1-烷基-2-芳氧基乙基羧酸酯,而芳基环氧乙烷的反应则生成1-芳基-2-芳氧基乙基羧酸酯和2-芳基-2-芳氧基乙基羧酸酯的混合物。在硫代芳基羧酸酯和二芳基碳酸酯与环氧乙烷的反应中也得到了类似的结果。在110至130°C的温度范围内,测定了苯甲酸乙酯与苯氧甲基环氧乙烷(PMO)在三丁胺(n-Bu3N)催化下的反应速率,可以用-d[PMO]/dt=k2[n-Bu3N]·[PMO]表示。从阿伦尼乌斯图计算出的表观活化能为85.8 kJ/mol。三丁胺催化的反应被认为是通过两性离子进行的,n-Bu3\overset+NCH2CH(R)O−和n-Bu3\overset+NCH(R)CH2O−,它们攻击芳基羧酸酯。