Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40,...Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40, the details of NK's capture of various Aβ species and reduction of plasma Aβ42/Aβ40 are uncharacterized. In this study, the Aβ42/Aβ40-degrading ability of NK was investigated using five Aβs and AD model mice. The C-terminal region of Aβ42/Aβ40(Gly29 to Val40)was primarily required for NK capture, and the integrated conformation in Aβ42/Aβ40 aggregates was a more efficient target for NK catalysis. Further, suspended Aβ42/Aβ40 oligomers were more easily captured by NK than suspended Aβ42/Aβ40 fibrils, while deposited Aβ42/Aβ40 fibrils recruited more NK than deposited Aβ42/Aβ40 oligomers. Although most NK was likely lost during NK uptake and/or entry into the blood, a small fraction of NK showed good plasma Aβ42/Aβ40-degrading efficacy after entering the blood due to NK's stability in the plasma of AD mice for at least 9 days. It was concluded that oral administration of NK is a feasible approach for peripheral Aβ42/Aβ40 clearance. This implies that NK might serve as an anti-Aβ42 agent for the treatment of Aβ42/Aβ40-related diseases such as AD.展开更多
Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensivel...Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensively investigated the emission,biosynthesis,and biological function of the floral scent in a night-blossoming waterlily Nymphaea prolifera.The headspace volatile collection combined with GC-MS analysis showed that the floral scent of N.prolifera is predominately comprised by methylated benzenoids including anisole,veratrole,guaiacol,and methoxyanisole.Moreover,the emission of these floral benzenoids in N.prolifera exhibited temporal and spatial pattern with circadian rhythm and tissue specificity.By creating and mining transcriptomes of N.prolifera flowers,12 oxygen methyltransferases(NpOMTs)were functionally identified.By in vitro enzymatic assay,NpOMT3,6,and 7 could produce anisole and NpOMT5,7,9,produce guaiacol,whereas NpOMT3,6,9,11 catalyzed the formation of veratrole.Methoxyanisole was identified as the universal product of all NpOMTs.Expression patterns of NpOMTs provided implication for their roles in the production of the respective benzenoids.Phylogenetic analysis of OMTs suggested a Nymphaea-specific expansion of the OMT family,indicating the evolution of lineage-specific functions.In bioassays,anisole,veratrole,and guaiacol in the floral benzenoids were revealed to play the critical role in repelling waterlily aphids.Overall,this study indicates that the basal flowering plant N.prolifera has evolved a diversity and complexity of OMT genes for the biosynthesis of methylated benzenoids that can repel insects from feeding the flowers.These findings provide new insights into the evolutional mechanism and ecological significance of the floral scent from early-diverged flowering plants.展开更多
In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SO<sub>3</sub>H-functionalized ionic liquids(ILs) as catalysts wa...In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SO<sub>3</sub>H-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high catalytic activity and reusability with good to excellent yields of the desired products.Hammett method has been used to determine the acidity order of these ionic liquids and the results are consistent with the catalytic activities observed in acetalization reaction.Maximum product yield of 93%was observed on using[PSPy][OTf]as catalyst and it can be reused at least 8 times without obvious activity loss.展开更多
Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves ...Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves high activation energy and could render high burning rate regime.This study reports on the sustainable fabrication of CuO nanoparticles as a novel catalyzing agent for APC oxidizer.Colloidal CuO nanoparticles with consistent product quality were fabricated by using hydrothermal processing.TEM micrographs demonstrated mono-dispersed particles of 15 nm particle size.XRD diffractogram demonstrated highly crystalline material.The synthesized colloidal CuO particles were effectively coated with APC particles via co-precipitation by using fast-crash solvent-antisolvent technique.The impact of copper oxide particles on APC thermal behavior has been investigated using DSC and TGA techniques.APC demonstrated an initial endothermic decomposition stage at 242℃ with subsequent two exothermic decomposition stages at 297,8℃ and 452.8℃ respectively.At 1 wt%,copper oxide offered decrease in initial endothermic decomposition stage by 30%.The main outcome of this study is that the two main exothermic decomposition peaks were merged into one single peak with an increase in total heat release by 53%.These novel features can inherit copper oxide particles unique catalyzing ability for advanced highly energetic systems.展开更多
In this paper,four functional substituted derivatives of cyclopalladated ferroccnyl-ketimines 1-4,which were as minetics of metal-dependent esterases for catalyzing the hydrolysis of thiophosphorie acid esters pestici...In this paper,four functional substituted derivatives of cyclopalladated ferroccnyl-ketimines 1-4,which were as minetics of metal-dependent esterases for catalyzing the hydrolysis of thiophosphorie acid esters pesticides,were synthesized and characterized.All the four cyclopalladated complexes can effieiently catalyze the degradation of thiophosphoric acid pesticides,such as methyl parathion.The PD catalyst with coordinated oxime is more active and exhibits an inereased seleetivity towards sulfur containing pesticides.展开更多
An asymmetric borane reduction of prochiral ketones catalyzed by simple amino alcohols and corresponding amino acids was examined to give alcohols with e.e. value up to 92% .
Oxidation of alkybenzenes PhCH<sub>2</sub>R(R=H, CH<sub>3</sub>, C<sub>2</sub>H<sub>5</sub> and n-C<sub>3</sub>H<sub>7</sub>) under 1 atm. of O...Oxidation of alkybenzenes PhCH<sub>2</sub>R(R=H, CH<sub>3</sub>, C<sub>2</sub>H<sub>5</sub> and n-C<sub>3</sub>H<sub>7</sub>) under 1 atm. of O<sub>2</sub> or air catalyzed by iron(Ⅱ, Ⅲ)-2,2’-bipyridine and 1,10-phenanthroline complexes, affords the aryl-substituted ketones and alcohols with the conversion of 15.00%~34.58% containing of 97.60%~99.80% ketones and alcohols. The turnover numbers of these catalysts are over 3500 mol-cat. <sup>-1</sup>for 3.5 h.展开更多
Three inexpensive and air-/moisture-stable Salen-Cu complexes 1-3 were evaluated to be a novel class of catalysts for the N-arylation of imidazoles with aryl halides. A variety of aryl iodides, bromides underwent the ...Three inexpensive and air-/moisture-stable Salen-Cu complexes 1-3 were evaluated to be a novel class of catalysts for the N-arylation of imidazoles with aryl halides. A variety of aryl iodides, bromides underwent the coupling with imida-zoles, promoted by the complex 3, in moderate to excellent yields without the protection by an inert gas.展开更多
A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it wa...A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it was found that reaction solvent is one of important factors in this catalytic system. Keyword: Palladium catalyzed, preparation, stilbazole.展开更多
Unfixed reactive dyes stained on cotton fabric could be removed using Fe-tetra-amido macro-cyclic ligands( TAML) / H_2O_2 catalyzed oxidation system( COS). The colored washing-off wastewater also could be decolorized ...Unfixed reactive dyes stained on cotton fabric could be removed using Fe-tetra-amido macro-cyclic ligands( TAML) / H_2O_2 catalyzed oxidation system( COS). The colored washing-off wastewater also could be decolorized simultaneously in the same system. The decolourization kinetics showed that the decolourization ratio of reactive dyes in water could reach at least 80% at room temperature in 10 min,which followed the law of pseudo-first order reaction kinetics. The effects of the COS washing-off process parameters on the decolourization ratio,chemical oxygen demand( COD) of wastewater,K/S value,color fastness,color difference,and bursting strength were investigated in detail. The results showed that color fastness properties and final shade of fabric treated by COS were very similar to conventional soaping. The reactive dye molecules in wash-off bath were destroyed using the COS,potentially reduced COD which generated during conventional washing-off procedure.展开更多
Efficient catalysis of functinnatized β-cyctodextrins bearing aninoatkytimino groups for atdot condensations of nitrobenzatdehydes and acetone has been effected and substantiated by preparative
Four stereoisomers of a copper-(Schiff-base) complex with double chiral centers were applied to catalyze the asymmetric cyclopropanation. Two of the stereoisomers were also efficient catalysts affording high enantiome...Four stereoisomers of a copper-(Schiff-base) complex with double chiral centers were applied to catalyze the asymmetric cyclopropanation. Two of the stereoisomers were also efficient catalysts affording high enantiomeric excess of up to 91.8%. A mechanism that predicts the observed results accurately was proposed.展开更多
The kinetics of phase transfer catalyzed (PTC) disproportionation of elemental sulfur was studied in the range of OH<sup>-</sup> concentrationlin the aqueous phase from 0.02 to 0.14 mol/dm<sup>3<...The kinetics of phase transfer catalyzed (PTC) disproportionation of elemental sulfur was studied in the range of OH<sup>-</sup> concentrationlin the aqueous phase from 0.02 to 0.14 mol/dm<sup>3</sup> and temperature from 45 to 70℃. A kinetic expression, R<sub>s</sub>a=k*[Q<sup>+</sup>]<sub>aq</sub>[OH<sup>-</sup>]<sub>aq</sub>[S]<sub>org</sub><sup>1/2</sup>, derived from the theory of mass transfer with rapid chemical reaction in liquid liquid system can be adopted to correlate the experimental data, and the apparent activation energy of the reaction was found to be 79kJ/mol. Kinetic evidence for PTC reaction of the system was given and a mechanism of PTC disproportionation of elemental sulfur was proposed.展开更多
The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to ...The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to epoxy group and 0. 74 order with respect to dimethylbenzylamine. The reaction rate constants at various temperatures and activation energy were determined. The mechanism of this reaction was discussed. Keywords Tetrabromobisphenol-A, Bromo-epoxy resin, Oleic acid kinetics, Reaction展开更多
Asymmetric syntheses of both enantiomerically pure (+) and (-) 5-oxo-endo-tricyclo [5.2.1.0.<sup>2,6</sup>] deca-3, 8-diene 1 was described. The key step is the use of enzyme-catalyzed hydrolysis of me...Asymmetric syntheses of both enantiomerically pure (+) and (-) 5-oxo-endo-tricyclo [5.2.1.0.<sup>2,6</sup>] deca-3, 8-diene 1 was described. The key step is the use of enzyme-catalyzed hydrolysis of meso-diacetate 5.展开更多
The configuration of the hydroxy acid 2, a product from base-catalyzedautoxidation of 3α,5-cyclo-5α-cholestane-6-one,was established on the basis of NMRtechniques and the mechanism of the formation of 2 was discussed.
(?)-Aryl-(?)-cyanosulfones are prepared under mild conditions withgood yields by using palladium-catalyzed coupling reaction between arylhalides and (?)-cyanosulfones in the presence of phase transfer catalyst.
Oxidation of ethylbenzene, n-propylbcnzene and n-butylbenzene gives the corresponding ketones and alcohols in good yields by organic polymer supported low—valent Ru (Ⅱ) complexes under 1 atm. of air or oxygen at 100...Oxidation of ethylbenzene, n-propylbcnzene and n-butylbenzene gives the corresponding ketones and alcohols in good yields by organic polymer supported low—valent Ru (Ⅱ) complexes under 1 atm. of air or oxygen at 100℃ in the absence of solvent. The calalytic selectivity to total ketone and alcohol ranged from 98.7% to 100%. The polymer complex polymer—bipy—Ru—bipy (bipy=2, 2’—bipyridine) is very stable and can be reused for 5 times (each for 5h) without appreciable change in catalytic activity.展开更多
Solid superacid perfluorooctanesulfonic acid(POSA)catalyzed Friedel-Craftsalkylation of aromatic hydrocarbons with olefins in gas-liquid phase.The alkylationsgave good yields with simple operation and easy work up.The...Solid superacid perfluorooctanesulfonic acid(POSA)catalyzed Friedel-Craftsalkylation of aromatic hydrocarbons with olefins in gas-liquid phase.The alkylationsgave good yields with simple operation and easy work up.The amount of the catalystused in the reactions was small and could be reused.The optimum temperature of thereactions and the effect of the amount of the catalyst used in the reactions are alsodiscussed.展开更多
基金supported by the National Natural Science Foundation of China Program (No. 31970883)。
文摘Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40, the details of NK's capture of various Aβ species and reduction of plasma Aβ42/Aβ40 are uncharacterized. In this study, the Aβ42/Aβ40-degrading ability of NK was investigated using five Aβs and AD model mice. The C-terminal region of Aβ42/Aβ40(Gly29 to Val40)was primarily required for NK capture, and the integrated conformation in Aβ42/Aβ40 aggregates was a more efficient target for NK catalysis. Further, suspended Aβ42/Aβ40 oligomers were more easily captured by NK than suspended Aβ42/Aβ40 fibrils, while deposited Aβ42/Aβ40 fibrils recruited more NK than deposited Aβ42/Aβ40 oligomers. Although most NK was likely lost during NK uptake and/or entry into the blood, a small fraction of NK showed good plasma Aβ42/Aβ40-degrading efficacy after entering the blood due to NK's stability in the plasma of AD mice for at least 9 days. It was concluded that oral administration of NK is a feasible approach for peripheral Aβ42/Aβ40 clearance. This implies that NK might serve as an anti-Aβ42 agent for the treatment of Aβ42/Aβ40-related diseases such as AD.
基金This work was supported by the National Natural Science Foundation of China(31872140,31470693,31100503)the Natural Science Foundation of Zhejiang Province(LY18C160006)+1 种基金the Zhejiang Provincial Key Laboratory of Characteristic Aquatic Vegetable Breeding and Cultivation Open Fund Project(KL-2022-01,KL-2022-02)the Project for Science and Technology in Jinhua City(Grant No.2019-2-002).The authors thank TopEdit(www.topeditsci.com)for its linguistic assistance during the preparation of this manuscript.
文摘Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensively investigated the emission,biosynthesis,and biological function of the floral scent in a night-blossoming waterlily Nymphaea prolifera.The headspace volatile collection combined with GC-MS analysis showed that the floral scent of N.prolifera is predominately comprised by methylated benzenoids including anisole,veratrole,guaiacol,and methoxyanisole.Moreover,the emission of these floral benzenoids in N.prolifera exhibited temporal and spatial pattern with circadian rhythm and tissue specificity.By creating and mining transcriptomes of N.prolifera flowers,12 oxygen methyltransferases(NpOMTs)were functionally identified.By in vitro enzymatic assay,NpOMT3,6,and 7 could produce anisole and NpOMT5,7,9,produce guaiacol,whereas NpOMT3,6,9,11 catalyzed the formation of veratrole.Methoxyanisole was identified as the universal product of all NpOMTs.Expression patterns of NpOMTs provided implication for their roles in the production of the respective benzenoids.Phylogenetic analysis of OMTs suggested a Nymphaea-specific expansion of the OMT family,indicating the evolution of lineage-specific functions.In bioassays,anisole,veratrole,and guaiacol in the floral benzenoids were revealed to play the critical role in repelling waterlily aphids.Overall,this study indicates that the basal flowering plant N.prolifera has evolved a diversity and complexity of OMT genes for the biosynthesis of methylated benzenoids that can repel insects from feeding the flowers.These findings provide new insights into the evolutional mechanism and ecological significance of the floral scent from early-diverged flowering plants.
基金supported by National 863 High-Tech Research and Development Program of China(No. 2007AA05Z101)
文摘In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SO<sub>3</sub>H-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high catalytic activity and reusability with good to excellent yields of the desired products.Hammett method has been used to determine the acidity order of these ionic liquids and the results are consistent with the catalytic activities observed in acetalization reaction.Maximum product yield of 93%was observed on using[PSPy][OTf]as catalyst and it can be reused at least 8 times without obvious activity loss.
文摘Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves high activation energy and could render high burning rate regime.This study reports on the sustainable fabrication of CuO nanoparticles as a novel catalyzing agent for APC oxidizer.Colloidal CuO nanoparticles with consistent product quality were fabricated by using hydrothermal processing.TEM micrographs demonstrated mono-dispersed particles of 15 nm particle size.XRD diffractogram demonstrated highly crystalline material.The synthesized colloidal CuO particles were effectively coated with APC particles via co-precipitation by using fast-crash solvent-antisolvent technique.The impact of copper oxide particles on APC thermal behavior has been investigated using DSC and TGA techniques.APC demonstrated an initial endothermic decomposition stage at 242℃ with subsequent two exothermic decomposition stages at 297,8℃ and 452.8℃ respectively.At 1 wt%,copper oxide offered decrease in initial endothermic decomposition stage by 30%.The main outcome of this study is that the two main exothermic decomposition peaks were merged into one single peak with an increase in total heat release by 53%.These novel features can inherit copper oxide particles unique catalyzing ability for advanced highly energetic systems.
文摘In this paper,four functional substituted derivatives of cyclopalladated ferroccnyl-ketimines 1-4,which were as minetics of metal-dependent esterases for catalyzing the hydrolysis of thiophosphorie acid esters pesticides,were synthesized and characterized.All the four cyclopalladated complexes can effieiently catalyze the degradation of thiophosphoric acid pesticides,such as methyl parathion.The PD catalyst with coordinated oxime is more active and exhibits an inereased seleetivity towards sulfur containing pesticides.
文摘An asymmetric borane reduction of prochiral ketones catalyzed by simple amino alcohols and corresponding amino acids was examined to give alcohols with e.e. value up to 92% .
文摘Oxidation of alkybenzenes PhCH<sub>2</sub>R(R=H, CH<sub>3</sub>, C<sub>2</sub>H<sub>5</sub> and n-C<sub>3</sub>H<sub>7</sub>) under 1 atm. of O<sub>2</sub> or air catalyzed by iron(Ⅱ, Ⅲ)-2,2’-bipyridine and 1,10-phenanthroline complexes, affords the aryl-substituted ketones and alcohols with the conversion of 15.00%~34.58% containing of 97.60%~99.80% ketones and alcohols. The turnover numbers of these catalysts are over 3500 mol-cat. <sup>-1</sup>for 3.5 h.
文摘Three inexpensive and air-/moisture-stable Salen-Cu complexes 1-3 were evaluated to be a novel class of catalysts for the N-arylation of imidazoles with aryl halides. A variety of aryl iodides, bromides underwent the coupling with imida-zoles, promoted by the complex 3, in moderate to excellent yields without the protection by an inert gas.
基金This work was supported by Foundation from President of the Chinese Academic of Science and NSFC.
文摘A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it was found that reaction solvent is one of important factors in this catalytic system. Keyword: Palladium catalyzed, preparation, stilbazole.
基金National Key Technology R&D Program,China(No.2011BAE07B08)the Fundamental Research Funds for the Central Universities,China(No.2232013D3-26)
文摘Unfixed reactive dyes stained on cotton fabric could be removed using Fe-tetra-amido macro-cyclic ligands( TAML) / H_2O_2 catalyzed oxidation system( COS). The colored washing-off wastewater also could be decolorized simultaneously in the same system. The decolourization kinetics showed that the decolourization ratio of reactive dyes in water could reach at least 80% at room temperature in 10 min,which followed the law of pseudo-first order reaction kinetics. The effects of the COS washing-off process parameters on the decolourization ratio,chemical oxygen demand( COD) of wastewater,K/S value,color fastness,color difference,and bursting strength were investigated in detail. The results showed that color fastness properties and final shade of fabric treated by COS were very similar to conventional soaping. The reactive dye molecules in wash-off bath were destroyed using the COS,potentially reduced COD which generated during conventional washing-off procedure.
文摘Efficient catalysis of functinnatized β-cyctodextrins bearing aninoatkytimino groups for atdot condensations of nitrobenzatdehydes and acetone has been effected and substantiated by preparative
文摘Four stereoisomers of a copper-(Schiff-base) complex with double chiral centers were applied to catalyze the asymmetric cyclopropanation. Two of the stereoisomers were also efficient catalysts affording high enantiomeric excess of up to 91.8%. A mechanism that predicts the observed results accurately was proposed.
文摘The kinetics of phase transfer catalyzed (PTC) disproportionation of elemental sulfur was studied in the range of OH<sup>-</sup> concentrationlin the aqueous phase from 0.02 to 0.14 mol/dm<sup>3</sup> and temperature from 45 to 70℃. A kinetic expression, R<sub>s</sub>a=k*[Q<sup>+</sup>]<sub>aq</sub>[OH<sup>-</sup>]<sub>aq</sub>[S]<sub>org</sub><sup>1/2</sup>, derived from the theory of mass transfer with rapid chemical reaction in liquid liquid system can be adopted to correlate the experimental data, and the apparent activation energy of the reaction was found to be 79kJ/mol. Kinetic evidence for PTC reaction of the system was given and a mechanism of PTC disproportionation of elemental sulfur was proposed.
文摘The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to epoxy group and 0. 74 order with respect to dimethylbenzylamine. The reaction rate constants at various temperatures and activation energy were determined. The mechanism of this reaction was discussed. Keywords Tetrabromobisphenol-A, Bromo-epoxy resin, Oleic acid kinetics, Reaction
文摘Asymmetric syntheses of both enantiomerically pure (+) and (-) 5-oxo-endo-tricyclo [5.2.1.0.<sup>2,6</sup>] deca-3, 8-diene 1 was described. The key step is the use of enzyme-catalyzed hydrolysis of meso-diacetate 5.
文摘The configuration of the hydroxy acid 2, a product from base-catalyzedautoxidation of 3α,5-cyclo-5α-cholestane-6-one,was established on the basis of NMRtechniques and the mechanism of the formation of 2 was discussed.
基金Supported by Natural Science Foundation of Zhejiang Province
文摘(?)-Aryl-(?)-cyanosulfones are prepared under mild conditions withgood yields by using palladium-catalyzed coupling reaction between arylhalides and (?)-cyanosulfones in the presence of phase transfer catalyst.
文摘Oxidation of ethylbenzene, n-propylbcnzene and n-butylbenzene gives the corresponding ketones and alcohols in good yields by organic polymer supported low—valent Ru (Ⅱ) complexes under 1 atm. of air or oxygen at 100℃ in the absence of solvent. The calalytic selectivity to total ketone and alcohol ranged from 98.7% to 100%. The polymer complex polymer—bipy—Ru—bipy (bipy=2, 2’—bipyridine) is very stable and can be reused for 5 times (each for 5h) without appreciable change in catalytic activity.
文摘Solid superacid perfluorooctanesulfonic acid(POSA)catalyzed Friedel-Craftsalkylation of aromatic hydrocarbons with olefins in gas-liquid phase.The alkylationsgave good yields with simple operation and easy work up.The amount of the catalystused in the reactions was small and could be reused.The optimum temperature of thereactions and the effect of the amount of the catalyst used in the reactions are alsodiscussed.