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
The amino acids post-modified ionic liquids-based hybrid monolithic columns were successfully developed.For the first step,using 1-vinyl-3-dodecylimidazole bromide(VDI·Br)and polyhedral oligomeric silsesquioxane ...The amino acids post-modified ionic liquids-based hybrid monolithic columns were successfully developed.For the first step,using 1-vinyl-3-dodecylimidazole bromide(VDI·Br)and polyhedral oligomeric silsesquioxane methacryl substituted(POSS-MA)as monomer and crosslinking agent,the monolithic POSS-VDI matrix material was polymerized in 100μm capillary.The prepared POSS-VDI column is of ion-exchange/reverse-phase mixed-mode retention characteristics.The column e fficiency reached 137,000 N/m for thioureas.The POSS-VDI column has also been successfully applied to recognize and analyze the eff ective components of Traditional Chinese Medicines Fangji and the Root of Kudzu Vine.Furthermore,based on its good chromatographic performances,in the second step,amino acids L-Proline(L-Pro),Glycine(Gly)or DLPhenylalanine(DL-Phe)were further exploited as the anion exchangers to post-modify the POSS-VDI column.The new POSS-VDI-Pro,POSS-VDI-Gly and POSS-VDI-Phe columns exhibited diff erent separation selectivity for the complex egg white protein sample.The present work provides a good route to fabricate versatile amino acids and ionic liquids modified monolithic columns with good separation selectivity.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.
基金financial support from Hundred Outstanding Innovative Talents in Universities of Hebei Province(SLRC2019016)Natural Science Foundation of Hebei Province(B2019201327)+2 种基金Young Talent of Hebei ProvinceNational Natural Science Foundation of China(21675039)Scientific Research Project of Hebei Provincial Administration of Traditional Chinese Medicine(2015116)。
文摘The amino acids post-modified ionic liquids-based hybrid monolithic columns were successfully developed.For the first step,using 1-vinyl-3-dodecylimidazole bromide(VDI·Br)and polyhedral oligomeric silsesquioxane methacryl substituted(POSS-MA)as monomer and crosslinking agent,the monolithic POSS-VDI matrix material was polymerized in 100μm capillary.The prepared POSS-VDI column is of ion-exchange/reverse-phase mixed-mode retention characteristics.The column e fficiency reached 137,000 N/m for thioureas.The POSS-VDI column has also been successfully applied to recognize and analyze the eff ective components of Traditional Chinese Medicines Fangji and the Root of Kudzu Vine.Furthermore,based on its good chromatographic performances,in the second step,amino acids L-Proline(L-Pro),Glycine(Gly)or DLPhenylalanine(DL-Phe)were further exploited as the anion exchangers to post-modify the POSS-VDI column.The new POSS-VDI-Pro,POSS-VDI-Gly and POSS-VDI-Phe columns exhibited diff erent separation selectivity for the complex egg white protein sample.The present work provides a good route to fabricate versatile amino acids and ionic liquids modified monolithic columns with good separation selectivity.