A series of amino-acid-based ionic liquids was synthesized via one-step protonation of the corresponding L-amiiio acid by utilizing an array of proton sources.The catalytic activity of the amino-acid-based ionic liqui...A series of amino-acid-based ionic liquids was synthesized via one-step protonation of the corresponding L-amiiio acid by utilizing an array of proton sources.The catalytic activity of the amino-acid-based ionic liquids for the Baeyer-Villiger oxidation of cyclic ketones was investigated using cyclopentanone as a model cycloketone.Theproline-based ionic liquid[ProH]CF3SO3 was shown to exliibit thebest catalytic activity.The reaction condition was optimized to give the following reagent ratio of h(cyclopentanone):n(catalyst):w(H2O2)=1:0.06:4,60℃and 6 h.Under the optimum conditions,the conversion of cyclopentanone was 96.57%and the selectivity forδ-valerolactone was 73.01%.The catalytic activity was shown to be constant after 4 cycles.A simple treatment was allowed for the recover and the reuse of[ProH]CF3S03.The successful utilization of[ProH]CF3SO3 to catalyze a host of cyclic ketones via Baeyer-Villiger oxidation clearly demonstrated the capacity of[ProH]CF3S03 to tolerate variation in the substrate.展开更多
基金Supported by the National Natural Science Foundation of China(No.21878166)the Taishan Scholar Project of Shandong Province,China(No.ts201511033)+1 种基金the Emphasis Development Plan of Shandong Province,China(Nos.2017GGX70102,2017GGX40107)the Open Project of the Chemistry Department in Qingdao University of Science and Technology of China(No.QUSTHX201811).
文摘A series of amino-acid-based ionic liquids was synthesized via one-step protonation of the corresponding L-amiiio acid by utilizing an array of proton sources.The catalytic activity of the amino-acid-based ionic liquids for the Baeyer-Villiger oxidation of cyclic ketones was investigated using cyclopentanone as a model cycloketone.Theproline-based ionic liquid[ProH]CF3SO3 was shown to exliibit thebest catalytic activity.The reaction condition was optimized to give the following reagent ratio of h(cyclopentanone):n(catalyst):w(H2O2)=1:0.06:4,60℃and 6 h.Under the optimum conditions,the conversion of cyclopentanone was 96.57%and the selectivity forδ-valerolactone was 73.01%.The catalytic activity was shown to be constant after 4 cycles.A simple treatment was allowed for the recover and the reuse of[ProH]CF3S03.The successful utilization of[ProH]CF3SO3 to catalyze a host of cyclic ketones via Baeyer-Villiger oxidation clearly demonstrated the capacity of[ProH]CF3S03 to tolerate variation in the substrate.
