Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-...Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-catalyst leading to 96.1%product yield.It can be reused five times to keep the product yield over 90%.These intriguing results are attributed to a new reaction mechanism,which is supported by theoretical calculations along with the measurements of ^(13)C NMR spectrum and Fourier transform infrared spectroscopy(FT-IR).The excellent catalytic activity can be traced to a CO_(2)-philic group along with an electrophilic hydrogen atom.Our work shows that incorporation of CO_(2)-philic group is an feasible pathway to develop the new efficient ionic liquids.展开更多
1,3-Bis(2,6-diisopropylphenyl)imidazolium chloride, [DIPrim]Cl, was used to produce a novel iron(III)-containing imidazolium salt [DIPrim][FeCl 4 ], which included a N,N-diarylimidazolium cation (R = 2,6-diisopropylph...1,3-Bis(2,6-diisopropylphenyl)imidazolium chloride, [DIPrim]Cl, was used to produce a novel iron(III)-containing imidazolium salt [DIPrim][FeCl 4 ], which included a N,N-diarylimidazolium cation (R = 2,6-diisopropylphenyl), [DIPrim] + , and tetrachloroferrate(III) anion, [FeCl 4 ]. This compound was an effective and easy-to-use catalyst for the cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides bearing -hydrogens. After simply decanting the cross-coupling product in the ether layer, [DIPrim][FeCl 4 ] could be reused in at least four successive runs without significant loss of catalytic activity.展开更多
A series of iron(III)-containing imidazolium salts of the general formula [DRim][FeX 4 ] (R=2,6-diisopropylphenyl, IPr, X=Cl, 1; R=IPr, X=Br, 2; R=tertbutyl, t Bu, X=Cl, 3; R=isopropyl, i Pr, X=Cl, 4; R=benzyl, Bn, X=...A series of iron(III)-containing imidazolium salts of the general formula [DRim][FeX 4 ] (R=2,6-diisopropylphenyl, IPr, X=Cl, 1; R=IPr, X=Br, 2; R=tertbutyl, t Bu, X=Cl, 3; R=isopropyl, i Pr, X=Cl, 4; R=benzyl, Bn, X=Cl, 5; R=Bn, X=Br, 6) have been prepared in high yields via reactions of anhydrous ferric halides with equivalent of the corresponding N,N-dihydro- carby-limidazolium halides, where 2-6 are novel ones. All of the complexes were characterized by elemental analysis, Raman spectroscopy, electrospray ionization mass spectroscopy, and X-ray crystallography for 1 and 2. All of them were non-hygroscopic and air-stable, with four of them existing as solids (1-4) and two as liquids (5 and 6) at room temperature. A preliminary catalytic study on the coupling of 4-tolylmagnesium bromide with cyclohexyl bromide revealed that 1 and 3 possessed the highest activity. In comparison, 2, 4 and 5 exhibited moderate activity and the least active complex was 6.展开更多
The use of intramolecular reactions involving palladium/imidazolium salts to synthesize hetero-cyclic compounds is described. Reactivity of phenyl, ethyl and methyl substituents leading to isolation of various isomeri...The use of intramolecular reactions involving palladium/imidazolium salts to synthesize hetero-cyclic compounds is described. Reactivity of phenyl, ethyl and methyl substituents leading to isolation of various isomeric products is also illustrated. Rearrangement of phenyl intermediates to furnish benzoxazoles is also mentioned.展开更多
A new synthetic method of 2,15 hexadecanedione from imidazalium salt and di Grignard reagent is reported. Imidazalium salt was used as tetrahydrofolate coenzyme model at formic acid oxidation level and di Grignard rea...A new synthetic method of 2,15 hexadecanedione from imidazalium salt and di Grignard reagent is reported. Imidazalium salt was used as tetrahydrofolate coenzyme model at formic acid oxidation level and di Grignard reagent as a nucleophile to which one carbon unit was transferred, the biomimetic synthesis of 2,15 hexadecanedione, a precursor of 3 methylcyclopentadecanone(muscon), was successfully accomplished by using the addition hydrolysis reaction of imidazolium salt with di Grignard reagent.展开更多
乙酸(1-二茂铁基乙基)酯(记为配体2)与1-异丙基咪唑经过季铵化反应,制备出具有大空间位阻和富电子的配体1-(1-二茂铁基乙基)-3-异丙基-1-咪唑碘盐(记为配体1),收率为88%。利用1 H NMR、13 C NMR对其结构进行了表征,并进一步考察了体系Pd...乙酸(1-二茂铁基乙基)酯(记为配体2)与1-异丙基咪唑经过季铵化反应,制备出具有大空间位阻和富电子的配体1-(1-二茂铁基乙基)-3-异丙基-1-咪唑碘盐(记为配体1),收率为88%。利用1 H NMR、13 C NMR对其结构进行了表征,并进一步考察了体系Pd(OAc)2/配体1催化4-甲氧基溴苯与苯硼酸的Suzuki-Miyaura偶联反应活性。实验发现:配体1在催化反应过程中可以有效地稳定Pd,在二氧六环反应介质中,碳酸铯为碱,1%Pd用量的条件下可以有效催化Suzuki-Miyaura偶联反应,加热回流3h,收率达93%。展开更多
Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deproton...Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation,by which the IL based biomass processing will be challenging.Herein,we demonstrated that the thermal stability of normal acetate-based imidazolim[C8C1Im][OAc]could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL([C4C1Im][NTf2]).When the molar fraction of[C8C1Im][OAc]was 0.3,the thermal stability of[C8C1Im][OAc]could be significantly improved(ΔT5%dec=+43°C).Detailed information obtained from thermal gravimetric analysis(TGA)and nuclear magnetic resonance(NMR)revealed that the addition of[C4C1 Im][NTf2]played a significant role in enhancing the thermal stability of[C8C1Im][OAc].It was proposed that the formation of an anion–π+structure network between[C8C1 Im][OAc]and[C4C1Im][NTf2]via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.展开更多
基金supported by the National Natural Science Foundation of China(21975064)Program of Henan Center for Outstanding Overseas Scientists(GZS2020011)+1 种基金Henan University's first-class discipline science and technology research project(2018YLTD07,2018YLZDYJ11,2019YLZDYJ09)the Excellent Foreign Experts Project of Henan University。
文摘Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-catalyst leading to 96.1%product yield.It can be reused five times to keep the product yield over 90%.These intriguing results are attributed to a new reaction mechanism,which is supported by theoretical calculations along with the measurements of ^(13)C NMR spectrum and Fourier transform infrared spectroscopy(FT-IR).The excellent catalytic activity can be traced to a CO_(2)-philic group along with an electrophilic hydrogen atom.Our work shows that incorporation of CO_(2)-philic group is an feasible pathway to develop the new efficient ionic liquids.
基金supported by the National Natural Science Foundation of China (20772089)the Key Laboratory of Organic Chemistry of Jiangsu Provincethe Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘1,3-Bis(2,6-diisopropylphenyl)imidazolium chloride, [DIPrim]Cl, was used to produce a novel iron(III)-containing imidazolium salt [DIPrim][FeCl 4 ], which included a N,N-diarylimidazolium cation (R = 2,6-diisopropylphenyl), [DIPrim] + , and tetrachloroferrate(III) anion, [FeCl 4 ]. This compound was an effective and easy-to-use catalyst for the cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides bearing -hydrogens. After simply decanting the cross-coupling product in the ether layer, [DIPrim][FeCl 4 ] could be reused in at least four successive runs without significant loss of catalytic activity.
基金supported by the National Natural Science Foundation of China (21172164)the Key Laboratory of Organic Chemistry of Jiangsu Provincethe Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘A series of iron(III)-containing imidazolium salts of the general formula [DRim][FeX 4 ] (R=2,6-diisopropylphenyl, IPr, X=Cl, 1; R=IPr, X=Br, 2; R=tertbutyl, t Bu, X=Cl, 3; R=isopropyl, i Pr, X=Cl, 4; R=benzyl, Bn, X=Cl, 5; R=Bn, X=Br, 6) have been prepared in high yields via reactions of anhydrous ferric halides with equivalent of the corresponding N,N-dihydro- carby-limidazolium halides, where 2-6 are novel ones. All of the complexes were characterized by elemental analysis, Raman spectroscopy, electrospray ionization mass spectroscopy, and X-ray crystallography for 1 and 2. All of them were non-hygroscopic and air-stable, with four of them existing as solids (1-4) and two as liquids (5 and 6) at room temperature. A preliminary catalytic study on the coupling of 4-tolylmagnesium bromide with cyclohexyl bromide revealed that 1 and 3 possessed the highest activity. In comparison, 2, 4 and 5 exhibited moderate activity and the least active complex was 6.
文摘The use of intramolecular reactions involving palladium/imidazolium salts to synthesize hetero-cyclic compounds is described. Reactivity of phenyl, ethyl and methyl substituents leading to isolation of various isomeric products is also illustrated. Rearrangement of phenyl intermediates to furnish benzoxazoles is also mentioned.
文摘A new synthetic method of 2,15 hexadecanedione from imidazalium salt and di Grignard reagent is reported. Imidazalium salt was used as tetrahydrofolate coenzyme model at formic acid oxidation level and di Grignard reagent as a nucleophile to which one carbon unit was transferred, the biomimetic synthesis of 2,15 hexadecanedione, a precursor of 3 methylcyclopentadecanone(muscon), was successfully accomplished by using the addition hydrolysis reaction of imidazolium salt with di Grignard reagent.
文摘乙酸(1-二茂铁基乙基)酯(记为配体2)与1-异丙基咪唑经过季铵化反应,制备出具有大空间位阻和富电子的配体1-(1-二茂铁基乙基)-3-异丙基-1-咪唑碘盐(记为配体1),收率为88%。利用1 H NMR、13 C NMR对其结构进行了表征,并进一步考察了体系Pd(OAc)2/配体1催化4-甲氧基溴苯与苯硼酸的Suzuki-Miyaura偶联反应活性。实验发现:配体1在催化反应过程中可以有效地稳定Pd,在二氧六环反应介质中,碳酸铯为碱,1%Pd用量的条件下可以有效催化Suzuki-Miyaura偶联反应,加热回流3h,收率达93%。
基金financially supported by the National Natural Science Foundation of China(21776026)the Liaoning Revitalization Talents Program(XLYC1902037)the start-up research funding of Beijing Institute of Technology(3160011181808)。
文摘Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation,by which the IL based biomass processing will be challenging.Herein,we demonstrated that the thermal stability of normal acetate-based imidazolim[C8C1Im][OAc]could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL([C4C1Im][NTf2]).When the molar fraction of[C8C1Im][OAc]was 0.3,the thermal stability of[C8C1Im][OAc]could be significantly improved(ΔT5%dec=+43°C).Detailed information obtained from thermal gravimetric analysis(TGA)and nuclear magnetic resonance(NMR)revealed that the addition of[C4C1 Im][NTf2]played a significant role in enhancing the thermal stability of[C8C1Im][OAc].It was proposed that the formation of an anion–π+structure network between[C8C1 Im][OAc]and[C4C1Im][NTf2]via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.
