In the presence of room temperature ionic liquids based on 1 butyl 3 methylimidazolium salt and butylpyridinium salt, cycloaddition of propylene oxide and carbon dioxide without any additional organic solvents was inv...In the presence of room temperature ionic liquids based on 1 butyl 3 methylimidazolium salt and butylpyridinium salt, cycloaddition of propylene oxide and carbon dioxide without any additional organic solvents was investigated. It was found that both cations and anions of the room temperature ionic liquids have strong influence on the catalytic activity. The better catalytic performance was achieved with 1 butyl 3 methylimidazolium tetrafluoroborate as a catalyst. A suitable CO 2/propylene oxide molar ratio is needed for the reaction, and the conversion of propylene oxide increases with the increase of reaction temperature. The ionic liquid as a catalyst for such reaction can be recycled.展开更多
In the presence of Dawson-type polyoxotungstate, α 2-[(n-C 4H 9) 4] (11-n)P 2W 17O 61(M n+·Br)[abbreviated as P 2W 17M·Br, M=Co(Ⅱ), Mn(Ⅲ), Cu(Ⅱ)] and saturated [(n-C 4H 9) 4N] 6P 2W 18O 62(abbreviated as...In the presence of Dawson-type polyoxotungstate, α 2-[(n-C 4H 9) 4] (11-n)P 2W 17O 61(M n+·Br)[abbreviated as P 2W 17M·Br, M=Co(Ⅱ), Mn(Ⅲ), Cu(Ⅱ)] and saturated [(n-C 4H 9) 4N] 6P 2W 18O 62(abbreviated as P 2W 18), cycloaddition reaction of carbon dioxide to propylene oxide were studied under moderate reaction conditions without any additional organic solvents. The experimental results indicated that the synthesis of propylene carbonate was completed in 98% yield and 100% selectivity by using {P 2W 17Co·Br} as the catalyst, while the P 2W 18 complex showed the lowest catalytic activity with less than 1% yield of propylene carbonate. The dependency of the catalytic activity on transition metal of mono-substituted polyoxometalate, P 2W 17M·Br, as well as the nucleophilicity of the bromide ion was concluded from the process analysis.展开更多
A modified silicon-containing arylacetylene resin with a well-defined organic-inorganic POSS functionality was successfully synthesized by Huisgen azide-alkyne 1,3-dipolar cycloaddition. The POSS hybridized resin exhi...A modified silicon-containing arylacetylene resin with a well-defined organic-inorganic POSS functionality was successfully synthesized by Huisgen azide-alkyne 1,3-dipolar cycloaddition. The POSS hybridized resin exhibits excellent thermal properties which were characterized by differential scanning calorimetry （DSC） and thermogravimetric analyses （TGA）. Scanning electron microscope （SEM） was used to characterize fracture surface of the hybridized polymer. The results show that phase separation occurs. The POSS moieties are aggregated each other in the polymer to form 200-400 nm domains.展开更多
The aim of ＂green chemistry＂ and ＂atom economy＂ is to utilize carbon dioxide and replace harmful reactants such as CO and phosgene for the production of cyclic carbonates. In this paper, metal-free catalysts inclu...The aim of ＂green chemistry＂ and ＂atom economy＂ is to utilize carbon dioxide and replace harmful reactants such as CO and phosgene for the production of cyclic carbonates. In this paper, metal-free catalysts including organic bases, ionic liquids, supported catalysts, organic copolymers and carbon materials for the synthesis of cyclic carbonates by the cycloaddition of carbon dioxide to epoxides are reviewed. Recent advances in the design of the catalysts and the understanding of the reaction mechanism are summarized and discussed. The synergistic effects of organic bases and hydrogen bond donors, organic bases and nucleophilic anions, hydrogen bond donors and nucleophilic anions and active components and supports are highlighted. The challenge is to develop metal-free catalysts suitable for carbon dioxide capture and fixation. The ultimate goal is to synthesize cyclic carbonates in a flow reactor directly using carbon dioxide from industrial flue gas at ambient temperature and atmospheric pressure. By using synergetic effects, a multi-functional approach can meet the design strategy of metal-free catalysts for carbon dioxide adsorption and activation as well as epoxide ring opening.展开更多
Global warming and climate change due to anthropogenic carbon dioxide(CO_(2))have aroused significant concerns at the global scale due to rapid economic growth in industries and other fields.Therefore,CO_(2)capture,us...Global warming and climate change due to anthropogenic carbon dioxide(CO_(2))have aroused significant concerns at the global scale due to rapid economic growth in industries and other fields.Therefore,CO_(2)capture,use,and storage have become particularly important.In this review,general background and methods for CO_(2)capture and separation,in particular,on ionic liquids(ILs)-based solvents and materials,are discussed.Comprehensive surveys of ILs for CO_(2)absorption are presented,which focused mainly on experimental researches,and then the concept is extended to functionalized absorbents and recent developments for CO_(2)capture.Major advantages and disadvantages of amines-based and ILs-based absorbents are discussed in this review.Solutions of traditional amines(MEA,MDEA,DEA,AMP,PZ,etc.)and ILs(conventional ILs,functionalized ILs,etc.)are summarized.Moreover,research progresses on CO_(2)separation are also introduced focusing mainly on amines and ILs-based membranes(e.g.supported amines membranes,SILMs).Futhermore,the fixation of CO_(2)into cyclic carbonates catalyzed by ILs(pure ILs,complex catalyst system with ILs,supported ILs,etc.)is summarized,clearly explaining the mechanism of CO_(2)fixation with ILs.Finally,exploration of some recent studies about CO_(2)capture and conversion by ILs and challenges for further progress are presented and related suggestions are put forward.展开更多
The selective synthesis of polypropylene carbonate （PPC） and cyclic propylene carbonate （CPC） from coupling reaction of CO_2 and propylene oxide （PO） is a long term pursuing target. Here we report that a tempera...The selective synthesis of polypropylene carbonate （PPC） and cyclic propylene carbonate （CPC） from coupling reaction of CO_2 and propylene oxide （PO） is a long term pursuing target. Here we report that a temperature controllable porphyrin aluminum catalyst using 5,10,15,20-tetra（1,2,3,4,5,6, 7,8-octahydro-1,4：5,8-dimethanoanthracen-g-yl）porphyrin as ligand, once in conjunction with suitable onium salt, achieved single cycloaddition or co- polymerization reaction. Only cydoaddition reaction happened at temperature above 75 ℃ to produce 100% CPC, whereas copolymerization became dominant to afford PPC with selectivity over 99% at 25℃, and the obtained PPC showed over 99% carbonate linkage and 92% head-to-tail structure. Based on systematic analysis of the electronic and steric feature in the porphyrin ligand, it was found that the electronic feature of the substituent in porphyrin ligand was decisive for PPC selectivity, porphyrin ligand bearing strong electron-donating substituents displayed a significantly reduced toler- ance towards increased temperature with respect to PPC formation. Therefore, temperature-responsive catalyst could be designed by suitable modifica- tion in porphyrin ligand, and such accurate synthesis of target product by one catalyst may create a useful and facile platform for selective PPC or CPC production.展开更多
This review summarizes the very recent advances in asymmetric reactions catalyzed by chiral phosphoric acids（CPAs）, a family of versatile catalysts that catalyze a broad range of reactions to afford diverse chiral m...This review summarizes the very recent advances in asymmetric reactions catalyzed by chiral phosphoric acids（CPAs）, a family of versatile catalysts that catalyze a broad range of reactions to afford diverse chiral molecules. In the past years, different kinds of chiral phosphoric acids have been designed and developed into a privileged class of catalysts in asymmetric synthesis. A number of remarkable achievements have been made by many groups around the world. Due to length limitation, this review only summarizes those works published from January 2016 to November 2017. Meanwhile, catalytic systems which combine metal catalysts and chiral phosphoric acids will not be discussed in this review.展开更多
Catalytic properties of the metal-organic framework Cr-MIL-101 in solvent-free cycloaddition of CO2 to epoxides to produce cyclic carbon- ates using tetrabutylammonium bromide as co-catalyst have been explored under m...Catalytic properties of the metal-organic framework Cr-MIL-101 in solvent-free cycloaddition of CO2 to epoxides to produce cyclic carbon- ates using tetrabutylammonium bromide as co-catalyst have been explored under mild reaction conditions （8 bar CO2, 25 ~C）. Styrene and propylene carbonates were formed with high yields （95% and 82%, respectively）. Catalytic performance of Cr-MIL-101 was compared with other MOFs： Fe-MIL-101, Zn-MOF-5 and HKUST-1, The catalytic properties of different quaternary ammonium bromides, Cr-MIL-101 as well as PW12/Cr-MIL-101 composite material have been assessed in oxidative carboxylation of styrene in the presence of both tert-butyl hydroperoxide and H202 as oxidants at 8-100bar CO2 and 25-80 ~C with selectivity to styrene carbonate up to 44% at 57% substrate conversion.展开更多
文摘In the presence of room temperature ionic liquids based on 1 butyl 3 methylimidazolium salt and butylpyridinium salt, cycloaddition of propylene oxide and carbon dioxide without any additional organic solvents was investigated. It was found that both cations and anions of the room temperature ionic liquids have strong influence on the catalytic activity. The better catalytic performance was achieved with 1 butyl 3 methylimidazolium tetrafluoroborate as a catalyst. A suitable CO 2/propylene oxide molar ratio is needed for the reaction, and the conversion of propylene oxide increases with the increase of reaction temperature. The ionic liquid as a catalyst for such reaction can be recycled.
文摘In the presence of Dawson-type polyoxotungstate, α 2-[(n-C 4H 9) 4] (11-n)P 2W 17O 61(M n+·Br)[abbreviated as P 2W 17M·Br, M=Co(Ⅱ), Mn(Ⅲ), Cu(Ⅱ)] and saturated [(n-C 4H 9) 4N] 6P 2W 18O 62(abbreviated as P 2W 18), cycloaddition reaction of carbon dioxide to propylene oxide were studied under moderate reaction conditions without any additional organic solvents. The experimental results indicated that the synthesis of propylene carbonate was completed in 98% yield and 100% selectivity by using {P 2W 17Co·Br} as the catalyst, while the P 2W 18 complex showed the lowest catalytic activity with less than 1% yield of propylene carbonate. The dependency of the catalytic activity on transition metal of mono-substituted polyoxometalate, P 2W 17M·Br, as well as the nucleophilicity of the bromide ion was concluded from the process analysis.
文摘A modified silicon-containing arylacetylene resin with a well-defined organic-inorganic POSS functionality was successfully synthesized by Huisgen azide-alkyne 1,3-dipolar cycloaddition. The POSS hybridized resin exhibits excellent thermal properties which were characterized by differential scanning calorimetry （DSC） and thermogravimetric analyses （TGA）. Scanning electron microscope （SEM） was used to characterize fracture surface of the hybridized polymer. The results show that phase separation occurs. The POSS moieties are aggregated each other in the polymer to form 200-400 nm domains.
基金supported by the National Science and Technology Support Project of China(2013BAC11B03)the National Natural Science Foundation of China(21401054,21476065,21273067)the Graduate Student Scientific Research Innovation Fund Project of Hunan Province(CX2015B082)~~
文摘The aim of ＂green chemistry＂ and ＂atom economy＂ is to utilize carbon dioxide and replace harmful reactants such as CO and phosgene for the production of cyclic carbonates. In this paper, metal-free catalysts including organic bases, ionic liquids, supported catalysts, organic copolymers and carbon materials for the synthesis of cyclic carbonates by the cycloaddition of carbon dioxide to epoxides are reviewed. Recent advances in the design of the catalysts and the understanding of the reaction mechanism are summarized and discussed. The synergistic effects of organic bases and hydrogen bond donors, organic bases and nucleophilic anions, hydrogen bond donors and nucleophilic anions and active components and supports are highlighted. The challenge is to develop metal-free catalysts suitable for carbon dioxide capture and fixation. The ultimate goal is to synthesize cyclic carbonates in a flow reactor directly using carbon dioxide from industrial flue gas at ambient temperature and atmospheric pressure. By using synergetic effects, a multi-functional approach can meet the design strategy of metal-free catalysts for carbon dioxide adsorption and activation as well as epoxide ring opening.
基金the Key Research and Development Project of Ningxia(2018BDE02057)the National Natural Science Foundation of China(219911100,219911101)for this work.
文摘Global warming and climate change due to anthropogenic carbon dioxide(CO_(2))have aroused significant concerns at the global scale due to rapid economic growth in industries and other fields.Therefore,CO_(2)capture,use,and storage have become particularly important.In this review,general background and methods for CO_(2)capture and separation,in particular,on ionic liquids(ILs)-based solvents and materials,are discussed.Comprehensive surveys of ILs for CO_(2)absorption are presented,which focused mainly on experimental researches,and then the concept is extended to functionalized absorbents and recent developments for CO_(2)capture.Major advantages and disadvantages of amines-based and ILs-based absorbents are discussed in this review.Solutions of traditional amines(MEA,MDEA,DEA,AMP,PZ,etc.)and ILs(conventional ILs,functionalized ILs,etc.)are summarized.Moreover,research progresses on CO_(2)separation are also introduced focusing mainly on amines and ILs-based membranes(e.g.supported amines membranes,SILMs).Futhermore,the fixation of CO_(2)into cyclic carbonates catalyzed by ILs(pure ILs,complex catalyst system with ILs,supported ILs,etc.)is summarized,clearly explaining the mechanism of CO_(2)fixation with ILs.Finally,exploration of some recent studies about CO_(2)capture and conversion by ILs and challenges for further progress are presented and related suggestions are put forward.
文摘The selective synthesis of polypropylene carbonate （PPC） and cyclic propylene carbonate （CPC） from coupling reaction of CO_2 and propylene oxide （PO） is a long term pursuing target. Here we report that a temperature controllable porphyrin aluminum catalyst using 5,10,15,20-tetra（1,2,3,4,5,6, 7,8-octahydro-1,4：5,8-dimethanoanthracen-g-yl）porphyrin as ligand, once in conjunction with suitable onium salt, achieved single cycloaddition or co- polymerization reaction. Only cydoaddition reaction happened at temperature above 75 ℃ to produce 100% CPC, whereas copolymerization became dominant to afford PPC with selectivity over 99% at 25℃, and the obtained PPC showed over 99% carbonate linkage and 92% head-to-tail structure. Based on systematic analysis of the electronic and steric feature in the porphyrin ligand, it was found that the electronic feature of the substituent in porphyrin ligand was decisive for PPC selectivity, porphyrin ligand bearing strong electron-donating substituents displayed a significantly reduced toler- ance towards increased temperature with respect to PPC formation. Therefore, temperature-responsive catalyst could be designed by suitable modifica- tion in porphyrin ligand, and such accurate synthesis of target product by one catalyst may create a useful and facile platform for selective PPC or CPC production.
基金Financial support from the National Natural Science Foundation of China (No. 21772046)the Recruitment Program of Global Experts(1000 Talents Plan)+1 种基金the Natural Science Foundation of Fujian Province(No. 2016J01064)Program of Innovative Research Team of Huaqiao University (No. Z14X0047)are gratefully acknowledged
文摘This review summarizes the very recent advances in asymmetric reactions catalyzed by chiral phosphoric acids（CPAs）, a family of versatile catalysts that catalyze a broad range of reactions to afford diverse chiral molecules. In the past years, different kinds of chiral phosphoric acids have been designed and developed into a privileged class of catalysts in asymmetric synthesis. A number of remarkable achievements have been made by many groups around the world. Due to length limitation, this review only summarizes those works published from January 2016 to November 2017. Meanwhile, catalytic systems which combine metal catalysts and chiral phosphoric acids will not be discussed in this review.
基金the Russian Foundation for Basic Research(RFBR grant12-03-31537)
文摘Catalytic properties of the metal-organic framework Cr-MIL-101 in solvent-free cycloaddition of CO2 to epoxides to produce cyclic carbon- ates using tetrabutylammonium bromide as co-catalyst have been explored under mild reaction conditions （8 bar CO2, 25 ~C）. Styrene and propylene carbonates were formed with high yields （95% and 82%, respectively）. Catalytic performance of Cr-MIL-101 was compared with other MOFs： Fe-MIL-101, Zn-MOF-5 and HKUST-1, The catalytic properties of different quaternary ammonium bromides, Cr-MIL-101 as well as PW12/Cr-MIL-101 composite material have been assessed in oxidative carboxylation of styrene in the presence of both tert-butyl hydroperoxide and H202 as oxidants at 8-100bar CO2 and 25-80 ~C with selectivity to styrene carbonate up to 44% at 57% substrate conversion.
