Catalytic hydrogenolysis of aromatic ether bonds is a highly promising strategy for upgrading lignin into small-molecule chemicals,which relies on developing innovative heterogeneous catalysts with high activity.Herei...Catalytic hydrogenolysis of aromatic ether bonds is a highly promising strategy for upgrading lignin into small-molecule chemicals,which relies on developing innovative heterogeneous catalysts with high activity.Herein,we designed porous zirconium phosphate nanosheet-supported Ru nanocatalysts(Ru/ZrPsheet)as the heterogeneous catalyst by a process combining ball milling and molten-salt(KNO_(3)).Very interestingly,the fabricated Ru/ZrPsheetshowed good catalytic performance on the transfer hydrogenolysis of various types of aromatic ether bonds contained in lignin,i.e.,4-O-5,a-O-4,β-O-4,and aryl-O-CH3,over a low Ru usage(<0.5 mol%)without using any acidic/basic additive.Detailed investigations indicated that the properties of Ru and the support were indispensable.The excellent activity of Ru/ZZrPsheetoriginated from the strong acidity and basicity of ZrPsheetand the higher electron density of metallic Ru0as well as the nanosheet structure of ZrPsheet.展开更多
Treatment of bis（2-dimethylaminoethyl） ether（BDMAE） with nickel acetate afforded a novel 3D nickel（Ⅱ） complex [Ni（BDMAE）（H2O）3·（CH3COO）2·（H2O）2] under solvothermal conditions. Its crystal stru...Treatment of bis（2-dimethylaminoethyl） ether（BDMAE） with nickel acetate afforded a novel 3D nickel（Ⅱ） complex [Ni（BDMAE）（H2O）3·（CH3COO）2·（H2O）2] under solvothermal conditions. Its crystal structure was characterized by elemental analysis, IR spectrum, PXRD and single-crystal X-ray diffraction analysis. The complex belongs to the orthorhombic system, space group C2221 with a=8.823（2）, b=13.932（3）, c=17.563（4） , V=2158.9（8） 3, Z=4, C（12）H（36）N2NiO（10）, Mr=427.14, Dc=1.314 g/cm3, F（000）=920 and μ=0.944 mm（-1）. Single-crystal X-ray diffraction reveals that the mononuclear nickel（Ⅱ） ion is six-coordinated to one oxygen, two nitrogen atoms of the BDMAE ligand and three oxygen atoms of coordinated water molecules. The complex exhibits a 3D supramolecular structure through a variety of intermolecular and intramolecular hydrogen bonding interactions. In addition, the complex has been investigated for catalytic properties towards the Henry reaction of nitromethane with p-nitrobenzaldehyde, and the results indicated that the 1-p-nitrophenyl-2-nitroethanol product was obtained in excellent yield under optimum conditions with the complex as the catalyst.展开更多
Production o f aromatics from lignin has attracted much attention. Because of the coexistence of C-O and C-C bonds and their complex combinations in the lignin macromolecular network, a plausible roadmap for de...Production o f aromatics from lignin has attracted much attention. Because of the coexistence of C-O and C-C bonds and their complex combinations in the lignin macromolecular network, a plausible roadmap for developing a lignin catalytic decomposition process could be developed by exploring the transformation mechanisms of various model compounds. Herein, decomposition of a lignin model compound, 2-phenoxyacetophenone （2-PAP）, was investigated over several ce-sium-exchanged polyoxometalate （Cs-POM） catalysts. Decomposition of 2-PAP can follow two dif-ferent mechanisms： an active hydrogen transfer mechanism or an oxonium cation mechanism. The mechanism for most reactions depends on the competition between the acidity and redox proper-ties of the catalysts. The catalysts of POMs perform the following functions： promoting active hy-drogen liberated from ethanol and causing formation of and then temporarily stabilizing oxonium cations from 2-PAP. The use of Cs-PMo, which with strong redox ability, enhances hydrogen libera-tion and promotes liberated hydrogen transfer to the reaction intermediates. As a consequence, complete conversion of 2-PAP （〉99%） with excellent selectivities to the desired products （98.6% for phenol and 91.1% for acetophenone） can be achieved.展开更多
Hexafluoropropylene oxide（HFPO） oligomers are toxic,bioaccumulative,and persistent organic pollutants（POPs）.Consuming the harmful chemicals to prevent them from releasing to nature is of serious significance as fa...Hexafluoropropylene oxide（HFPO） oligomers are toxic,bioaccumulative,and persistent organic pollutants（POPs）.Consuming the harmful chemicals to prevent them from releasing to nature is of serious significance as far as both natural environments and human health are concerned.In this study,investigation on degradation of HFPO oligomers to pentafluoropropionyl fluoride（PPF）,a valuable industrial chemical,is reported.Different combinations of alkali metal fluoride in either diglyme or tetraglyme under both flask and batch autoclave conditions were examined.Under the optimal reaction conditions,HFPO oligomers（n = 2-10） were completely degraded to PPF in over 90%yield.Reactions on200 g scale were tested and no deduction of efficiency was observed,which indicates the potential for practical industrial application of this chemistry.展开更多
A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic e...A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic ethers. Mechanism study shows the reaction involves a radical process.展开更多
基金financially supported by the National Natural Science Foundation of China(22072157,22293012,22179132,22121002)。
文摘Catalytic hydrogenolysis of aromatic ether bonds is a highly promising strategy for upgrading lignin into small-molecule chemicals,which relies on developing innovative heterogeneous catalysts with high activity.Herein,we designed porous zirconium phosphate nanosheet-supported Ru nanocatalysts(Ru/ZrPsheet)as the heterogeneous catalyst by a process combining ball milling and molten-salt(KNO_(3)).Very interestingly,the fabricated Ru/ZrPsheetshowed good catalytic performance on the transfer hydrogenolysis of various types of aromatic ether bonds contained in lignin,i.e.,4-O-5,a-O-4,β-O-4,and aryl-O-CH3,over a low Ru usage(<0.5 mol%)without using any acidic/basic additive.Detailed investigations indicated that the properties of Ru and the support were indispensable.The excellent activity of Ru/ZZrPsheetoriginated from the strong acidity and basicity of ZrPsheetand the higher electron density of metallic Ru0as well as the nanosheet structure of ZrPsheet.
基金supported by the National Natural Science Foundation of China(No.21271136)the Key Science Foundation of Anhui Provincial Education Department(No.KJ2016A772)the Research Team of Anhui Provincial Education Department(Photoelectric Information Materials and New Energy Devices)
文摘Treatment of bis（2-dimethylaminoethyl） ether（BDMAE） with nickel acetate afforded a novel 3D nickel（Ⅱ） complex [Ni（BDMAE）（H2O）3·（CH3COO）2·（H2O）2] under solvothermal conditions. Its crystal structure was characterized by elemental analysis, IR spectrum, PXRD and single-crystal X-ray diffraction analysis. The complex belongs to the orthorhombic system, space group C2221 with a=8.823（2）, b=13.932（3）, c=17.563（4） , V=2158.9（8） 3, Z=4, C（12）H（36）N2NiO（10）, Mr=427.14, Dc=1.314 g/cm3, F（000）=920 and μ=0.944 mm（-1）. Single-crystal X-ray diffraction reveals that the mononuclear nickel（Ⅱ） ion is six-coordinated to one oxygen, two nitrogen atoms of the BDMAE ligand and three oxygen atoms of coordinated water molecules. The complex exhibits a 3D supramolecular structure through a variety of intermolecular and intramolecular hydrogen bonding interactions. In addition, the complex has been investigated for catalytic properties towards the Henry reaction of nitromethane with p-nitrobenzaldehyde, and the results indicated that the 1-p-nitrophenyl-2-nitroethanol product was obtained in excellent yield under optimum conditions with the complex as the catalyst.
基金supported by the National Key Basic Research Program of China(973 program,2013CB934101)National Natural Science Foundation of China(21433002,21573046)+1 种基金China Postdoctoral Science Foundation(2016M601492)International Science and Technology Cooperation Projects of Guangxi(15104001-5)~~
文摘Production o f aromatics from lignin has attracted much attention. Because of the coexistence of C-O and C-C bonds and their complex combinations in the lignin macromolecular network, a plausible roadmap for developing a lignin catalytic decomposition process could be developed by exploring the transformation mechanisms of various model compounds. Herein, decomposition of a lignin model compound, 2-phenoxyacetophenone （2-PAP）, was investigated over several ce-sium-exchanged polyoxometalate （Cs-POM） catalysts. Decomposition of 2-PAP can follow two dif-ferent mechanisms： an active hydrogen transfer mechanism or an oxonium cation mechanism. The mechanism for most reactions depends on the competition between the acidity and redox proper-ties of the catalysts. The catalysts of POMs perform the following functions： promoting active hy-drogen liberated from ethanol and causing formation of and then temporarily stabilizing oxonium cations from 2-PAP. The use of Cs-PMo, which with strong redox ability, enhances hydrogen libera-tion and promotes liberated hydrogen transfer to the reaction intermediates. As a consequence, complete conversion of 2-PAP （〉99%） with excellent selectivities to the desired products （98.6% for phenol and 91.1% for acetophenone） can be achieved.
基金the National Natural Science Foundation of China (Nos. 21372127, 21572104)Program for New Century Excellent Talents in UniversityChanglu Engineering Research Center of New Chemical Materials for financial support
文摘Hexafluoropropylene oxide（HFPO） oligomers are toxic,bioaccumulative,and persistent organic pollutants（POPs）.Consuming the harmful chemicals to prevent them from releasing to nature is of serious significance as far as both natural environments and human health are concerned.In this study,investigation on degradation of HFPO oligomers to pentafluoropropionyl fluoride（PPF）,a valuable industrial chemical,is reported.Different combinations of alkali metal fluoride in either diglyme or tetraglyme under both flask and batch autoclave conditions were examined.Under the optimal reaction conditions,HFPO oligomers（n = 2-10） were completely degraded to PPF in over 90%yield.Reactions on200 g scale were tested and no deduction of efficiency was observed,which indicates the potential for practical industrial application of this chemistry.
基金supported by the National Natural Science Foundation of China (21572240)
文摘A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic ethers. Mechanism study shows the reaction involves a radical process.
