The effect of substituents and operating conditions on the electrochemical fluorination of alkyl phenylacetates in Et3N·4HF medium
作者:N. Ilayaraja、A. Manivel、D. Velayutham、M. Noel
DOI:10.1016/j.jfluchem.2007.10.007
日期:2008.3
Selective electrochemical fluorination of alkyl phenylacetates (Ph–CH2–COOR, where R is methyl, ethyl, n-propyl, n-butyl, i-propyl and sec-butyl) under galvanostatic conditions were reported in Et3N·4HF medium. Preparative electrolysis experiments were carried out both in pre-electrolysed dry Et3N·4HF and the same electrolyte medium without pre-electrolysis. Very little hydrolysed fluorinated products
烷基乙酸苯的选择性电化学氟化(PH-CH 2 -COOR,其中R为甲基,乙基,Ñ丙基,Ñ丁基,我-丙基和仲-丁基)恒电流条件下被报告在Et 3 N·4HF平台。在预电解干燥的Et 3 N·4HF和相同的电解质介质中进行了预电解实验,没有进行预电解。在预电解介质中几乎没有得到水解的氟化产物,其中从Et 3获得了大量导致氟化苯乙酸的水解产物。N·4HF不需预电解。在最佳实验条件下,可以实现高达87%的单氟酯选择性。获得的其他主要副产物是二氟烷基苯乙酸酯,一氟和二氟苯乙酸。在最初的阳离子自由基电氧化形成后,水解似乎是由质子的互变异构转化引发的。已采用19 F和1 H NMR光谱鉴定在电氧化过程中形成的次要成分。