摘要
采用一步法合成了[PPh_(3)][TfOH]_(2)、[TNOA][TfOH]_(2)、[TNOA][TfOH]和[PPh_(3)][TfOH]共4种离子液体。通过红外探针法对离子液体的酸性类型与酸性强弱进行了表征;同时对离子液体催化Fries重排选择性合成对羟基苯乙酮的收率进行了条件优化。结果表明,当选择[PPh_(3)][TfOH]_(2)作催化剂兼溶剂时,在反应温度为60℃、n(乙酸苯酯)∶n(离子液体)为1∶2、反应时间为6 h的条件下,选择性生成对羟基苯乙酮最高收率达到75%;催化剂可循环利用5次不失活。通过1HNMR监测反应前后催化剂结构变化,推导了其可能的反应机理。
Four kinds of ionic liquids(ILs),including[PPh_(3)][TfOH]_(2),[TNOA][TfOH]_(2),[TNOA][TfOH]and[PPh_(3)][TfOH],are synthesized via one-step method.The type and intensity of acidity of the ILs are characterized through FT-IR probe method.The catalytic performance of these Brønsted ILs is evaluated in selective synthesis of p-hydroxyacetophenone through Fries rearrangement process.It is shown that the yield of p-hydroxyacetophenone reaches 75%,the highest when[PPh_(3)][TfOH]_(2)is used as catalyst and solvent,the reaction temperature is at 60℃,n(PA):n(IL)=1:2,and the reaction time is 6 h.[PPh_(3)][TfOH]_(2)will not lose its activity after it has been recycled for 5 times.The changes of catalyst structure before and after the reaction are monitored by means of 1H NMR and the possible reaction mechanism is deduced.
作者
李萍
崔颖娜
张腾
曹洪玉
张殊佳
郑学仿
王爱玲
LI Ping;CUI Ying-na;ZHANG Teng;CAO Hong-yu;ZHANG Shu-jia;ZHENG Xue-fang;WANG Ai-ling(College of Environmental and Chemical Engineering,Dalian University,Dalian 116622,China;Liaoning Provincial Key Laboratory of Bioorganic Chemistry,Dalian University,Dalian 116622,China;College of Chemistry and Food Science,Yulin Normal University,Yulin 537000,China)
出处
《现代化工》
CAS
CSCD
北大核心
2023年第4期149-153,160,共6页
Modern Chemical Industry
基金
广西自然科学基金项目(2020GXNSFAA159126)
大连大学科研平台项目重点项目(202101ZD01)。