A new condensation reaction of β-keto-δ-valerolactones was developed. The condensation products are composed of a pair of isomers because of the formation ofintramolecular hydrogen bond. Their structures were confir...A new condensation reaction of β-keto-δ-valerolactones was developed. The condensation products are composed of a pair of isomers because of the formation ofintramolecular hydrogen bond. Their structures were confirmed by 1HNMR and elemental analysis.展开更多
The title compounds 3 and 4 condensed with aromatic aldehydes to give a--aroylsicinnamoyl ketene cyclic dithioacetals 5 and 6 with sodium ethoxide as the base. The stereochemistryofs and 6 was assigned as E-configurat...The title compounds 3 and 4 condensed with aromatic aldehydes to give a--aroylsicinnamoyl ketene cyclic dithioacetals 5 and 6 with sodium ethoxide as the base. The stereochemistryofs and 6 was assigned as E-configuration by 1H NMR.展开更多
The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in sol...The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in solution and eight compounds have been prepared. Their structures have been characterized by UV,IR,1~HNMR,HS and elemental analysis.展开更多
It was tried to develop the preparation method for microencapsulating the uycalyptus oil containing fine aqueous droplets by using the interfacial condensation reaction between hydroxyl propyl methyl cellulose and tan...It was tried to develop the preparation method for microencapsulating the uycalyptus oil containing fine aqueous droplets by using the interfacial condensation reaction between hydroxyl propyl methyl cellulose and tannic acid. Uycalyptus oil containing fine aqueous droplets was dispersed in the continuous water phase to form the (W/O)/W emulsion. Tannic acid and hydroxyl propyl methyl cellulose were dissolved in the inner aqueous droplets and in the outer continuous water phase, respectively. Tannic acid transferred through the oil phase from the inner water droplets to the interface between the oil phase and the continuous water phase and then, reacted with hydroxyl propyl methyl cellulose. In the experiment, the concentrations of hydroxyl propyl methyl cellulose and tannic acid were mainly changed stepwise. The uycalyptus oil containing the fine water droplets could be microencapsulated satisfactorily. It was found that the microcapsules were composed of the gelated hydroxyl propyl methyl cellulose film as the shell, the fine aqueous droplets as the first core and the oil droplet as the second core.展开更多
Synthesis of a novel series of N-pyrandione substituted amino acids and their esters 3 via a condensation reaction between pyrandione and amino acid or their derivatives in excess ethyl orthoformate without solvent is...Synthesis of a novel series of N-pyrandione substituted amino acids and their esters 3 via a condensation reaction between pyrandione and amino acid or their derivatives in excess ethyl orthoformate without solvent is described. The stereochemistry of 3 has been discussed.展开更多
Ionic liquids (ILs) with 1,3-disubstituted imidazolium cations and the dimethyl phosphate (DMP) anion, as well as the chloride anion were prepared and characterized by 1H NMR spectra, chromatographic and titrimetric p...Ionic liquids (ILs) with 1,3-disubstituted imidazolium cations and the dimethyl phosphate (DMP) anion, as well as the chloride anion were prepared and characterized by 1H NMR spectra, chromatographic and titrimetric purity control, and determination of the moisture content and thermal stability. ILs with the DMP anion decompose only at temperatures above 240°C. These ILs were tested as both reaction media (solvents) and catalysts for the Knoevenagel condensation reaction. The impact of the most significant structure elements of ILs was evaluated for the rates and yields of the condensation reaction. IL anions have the greatest effect on the condensation reactions, and even the chloride anion has some catalytic effect on the Knoevenagel condensation. Side chains in the imidazolium cations influence the reaction course very little. The ability of the imidazolium cations to form hydrogen bonding with the transition state of the condensation reaction leads to a remarkable slowdown in the reaction rates.展开更多
A new dimolybdenum(V)complex[(C_6H_4Cl)_2C(Ph)]_2[Mo_2(μ-Cl)_3Cl_4O_2][Mo_2(μ- Cl)_2Cl_4O_2(μ-OCOPh)]has been obtained in the reaction of PhCl with benzoyl peroxide (PhCO_2)_2 and MoCl_5.Its crystal structure has b...A new dimolybdenum(V)complex[(C_6H_4Cl)_2C(Ph)]_2[Mo_2(μ-Cl)_3Cl_4O_2][Mo_2(μ- Cl)_2Cl_4O_2(μ-OCOPh)]has been obtained in the reaction of PhCl with benzoyl peroxide (PhCO_2)_2 and MoCl_5.Its crystal structure has been determined by X-ray diffraction meth- ods.Spectroscopic characterization of the compound and ASED-MO calculation of the trityl cation are reported.展开更多
The ccndensation reactions occurred when heating bis(perfluoroalkane- sulfonyl)methanes with aromatic aldehydes in acetic acid anhydride and gave high yields of 1-aryl-2,2-di(perfluoroalkanesulfonyl)ethylenes The perf...The ccndensation reactions occurred when heating bis(perfluoroalkane- sulfonyl)methanes with aromatic aldehydes in acetic acid anhydride and gave high yields of 1-aryl-2,2-di(perfluoroalkanesulfonyl)ethylenes The perfluoroalkanesulfonyl groups R_FSO_2 are known as the strongest electron-attracting substituents^(1-2).This property is often used in the activation of C-C multiple and 2,2'-C-H bonds.The synthesis and reactions of perfluoroalkanesulfonyl substituted alkenes and alkynes are of great interest in synthetic organic chemistry^(3-6). Recently,Hanack^7 reported the preparation of 2-aryl-l-(perfluoroalkane- sulfonyl)acrylonitrile R_FSO_2C(CN)=CHAr.However,he failed to obtain the 1,1-di(perfluoroalkanesulfonyl)alkenes by the Knoevenagel reaction of bis(perfluoroalkanesulfonyl)methane with aldehydes.展开更多
Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthi...Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthio and an acyl group.This is resulted by the secondary reactio of the produced methanethiol to attack the more active carbonyl group.展开更多
The construction of C-N bonds is of great importance in the fields of biology,medicine,chemistry and materials science.Here,the replacement of organic base from pyridine to piperidine in the Knoevenagel condensation p...The construction of C-N bonds is of great importance in the fields of biology,medicine,chemistry and materials science.Here,the replacement of organic base from pyridine to piperidine in the Knoevenagel condensation process unexpectedly yields a series of novel organic molecules containing C-N bonds.Interestingly,the synthesis method does not require any external transition-metals catalysis,and photo-/electro-catalysis.Additionally,when the new compound 1b is added as a third component to a well-known binary system of PM6:Y6,the efficiency of the organic solar cell is significantly improved,resulting in an outstanding efficiency of 18.0%,which is one of the highest values reported to date for PM6:Y6-based ternary organic solar cells.展开更多
In order to synthesize an improved adsorbent for heavy metal ions,we studied the condensation reaction of chitosan with salicylaldehyde in ethanol to form a Schiff base.The effect irradiating the reaction using an ult...In order to synthesize an improved adsorbent for heavy metal ions,we studied the condensation reaction of chitosan with salicylaldehyde in ethanol to form a Schiff base.The effect irradiating the reaction using an ultrasonic liquid processor was contrasted with conventional methods.The IR spectra of condensed chitosan prepared by the two methods showed that their molecular structures were identical.The reaction conditions,including solvents,ultrasonic power density and irradiation time,pH,and reactant ratio,were optimized by orthogonal design.A shorter reaction time and a higher product yield were obtained using ultrasonic-assisted synthesis compared with the traditional method.A condensation degree of 89.63% was achieved using the optimized conditions:i.e.ultrasonic irradiation at 180 W for 60 min;95% ethanol as the solvent,pH 4.0,and salicylaldehyde:chitosan ratio of 6:1.展开更多
An efficient, environmentally friendly procedure is developed for the condensation of aldchydcs/kctoncs and activated methylene compounds by using an aminopropyl-functionalized MCM-41 catalyst in aqueous solution. Dif...An efficient, environmentally friendly procedure is developed for the condensation of aldchydcs/kctoncs and activated methylene compounds by using an aminopropyl-functionalized MCM-41 catalyst in aqueous solution. Different aldchydcs/kctoncs and activated methylene compounds gave the corresponding alkcncs in 78-97% isolated yields in mild reaction conditions. In comparison with organic solution, the aqueous solution gives higher yields in the same reaction conditions. Further more, the aminopropyl-functionalizcd MCM-41 in aqueous system can be reused for 8 flints without significant decrease of activity.展开更多
Three kind of aryl-substituted tri-benzyl sulfonium salts [ （4-phX）phSph2 ] PF6 [ X = S, O ] were prepared by the condensation of biphenyl sulfoxide with biphenyl sulfide, biphenyl ether or 1, 1＇ -biphenyl in the p...Three kind of aryl-substituted tri-benzyl sulfonium salts [ （4-phX）phSph2 ] PF6 [ X = S, O ] were prepared by the condensation of biphenyl sulfoxide with biphenyl sulfide, biphenyl ether or 1, 1＇ -biphenyl in the presence of polyphosphoric acid which can be used as dehydrate agent. The reaction condition was mild, such as reaction temperature between 40- 50 ℃ ,reactive time 2- 3 h, the yield of 4-（phenylthio）triphenylsulfonium hexafluorophosphate was 87.6%. The three kind sulfonium salts show better curing character to epoxy resin.展开更多
文摘A new condensation reaction of β-keto-δ-valerolactones was developed. The condensation products are composed of a pair of isomers because of the formation ofintramolecular hydrogen bond. Their structures were confirmed by 1HNMR and elemental analysis.
基金This work was supposed by the National Basic Research Program(973 Program)from the Ministry of Science and Technology of China(G1998051114)the National Natural Science Foundation of China(20272004)
文摘The title compounds 3 and 4 condensed with aromatic aldehydes to give a--aroylsicinnamoyl ketene cyclic dithioacetals 5 and 6 with sodium ethoxide as the base. The stereochemistryofs and 6 was assigned as E-configuration by 1H NMR.
文摘The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in solution and eight compounds have been prepared. Their structures have been characterized by UV,IR,1~HNMR,HS and elemental analysis.
文摘It was tried to develop the preparation method for microencapsulating the uycalyptus oil containing fine aqueous droplets by using the interfacial condensation reaction between hydroxyl propyl methyl cellulose and tannic acid. Uycalyptus oil containing fine aqueous droplets was dispersed in the continuous water phase to form the (W/O)/W emulsion. Tannic acid and hydroxyl propyl methyl cellulose were dissolved in the inner aqueous droplets and in the outer continuous water phase, respectively. Tannic acid transferred through the oil phase from the inner water droplets to the interface between the oil phase and the continuous water phase and then, reacted with hydroxyl propyl methyl cellulose. In the experiment, the concentrations of hydroxyl propyl methyl cellulose and tannic acid were mainly changed stepwise. The uycalyptus oil containing the fine water droplets could be microencapsulated satisfactorily. It was found that the microcapsules were composed of the gelated hydroxyl propyl methyl cellulose film as the shell, the fine aqueous droplets as the first core and the oil droplet as the second core.
基金the National Natural Science Foundation of China for the project support (No.29832050)
文摘Synthesis of a novel series of N-pyrandione substituted amino acids and their esters 3 via a condensation reaction between pyrandione and amino acid or their derivatives in excess ethyl orthoformate without solvent is described. The stereochemistry of 3 has been discussed.
文摘Ionic liquids (ILs) with 1,3-disubstituted imidazolium cations and the dimethyl phosphate (DMP) anion, as well as the chloride anion were prepared and characterized by 1H NMR spectra, chromatographic and titrimetric purity control, and determination of the moisture content and thermal stability. ILs with the DMP anion decompose only at temperatures above 240°C. These ILs were tested as both reaction media (solvents) and catalysts for the Knoevenagel condensation reaction. The impact of the most significant structure elements of ILs was evaluated for the rates and yields of the condensation reaction. IL anions have the greatest effect on the condensation reactions, and even the chloride anion has some catalytic effect on the Knoevenagel condensation. Side chains in the imidazolium cations influence the reaction course very little. The ability of the imidazolium cations to form hydrogen bonding with the transition state of the condensation reaction leads to a remarkable slowdown in the reaction rates.
文摘A new dimolybdenum(V)complex[(C_6H_4Cl)_2C(Ph)]_2[Mo_2(μ-Cl)_3Cl_4O_2][Mo_2(μ- Cl)_2Cl_4O_2(μ-OCOPh)]has been obtained in the reaction of PhCl with benzoyl peroxide (PhCO_2)_2 and MoCl_5.Its crystal structure has been determined by X-ray diffraction meth- ods.Spectroscopic characterization of the compound and ASED-MO calculation of the trityl cation are reported.
文摘The ccndensation reactions occurred when heating bis(perfluoroalkane- sulfonyl)methanes with aromatic aldehydes in acetic acid anhydride and gave high yields of 1-aryl-2,2-di(perfluoroalkanesulfonyl)ethylenes The perfluoroalkanesulfonyl groups R_FSO_2 are known as the strongest electron-attracting substituents^(1-2).This property is often used in the activation of C-C multiple and 2,2'-C-H bonds.The synthesis and reactions of perfluoroalkanesulfonyl substituted alkenes and alkynes are of great interest in synthetic organic chemistry^(3-6). Recently,Hanack^7 reported the preparation of 2-aryl-l-(perfluoroalkane- sulfonyl)acrylonitrile R_FSO_2C(CN)=CHAr.However,he failed to obtain the 1,1-di(perfluoroalkanesulfonyl)alkenes by the Knoevenagel reaction of bis(perfluoroalkanesulfonyl)methane with aldehydes.
文摘Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthio and an acyl group.This is resulted by the secondary reactio of the produced methanethiol to attack the more active carbonyl group.
基金supported by the National Natural Science Foundation of China(U21A20331)the National Science Fund for Distinguished Young Scholars(21925506)the Zhejiang Provincial Natural Science Foundation of China(LQ22E030013)。
文摘The construction of C-N bonds is of great importance in the fields of biology,medicine,chemistry and materials science.Here,the replacement of organic base from pyridine to piperidine in the Knoevenagel condensation process unexpectedly yields a series of novel organic molecules containing C-N bonds.Interestingly,the synthesis method does not require any external transition-metals catalysis,and photo-/electro-catalysis.Additionally,when the new compound 1b is added as a third component to a well-known binary system of PM6:Y6,the efficiency of the organic solar cell is significantly improved,resulting in an outstanding efficiency of 18.0%,which is one of the highest values reported to date for PM6:Y6-based ternary organic solar cells.
文摘Unexpected condensation products from β-keto-δ-valerolactones were obtained. Theirstructures were confirmed by 'HNMR spectrum and elemental analysis.
基金Supported by Doctoral Discipline Special Foundation,Education Ministry of China (No.20050561014)the National High Technology Research and Development Program of China (863 Program) (No.2007AA100405)
文摘In order to synthesize an improved adsorbent for heavy metal ions,we studied the condensation reaction of chitosan with salicylaldehyde in ethanol to form a Schiff base.The effect irradiating the reaction using an ultrasonic liquid processor was contrasted with conventional methods.The IR spectra of condensed chitosan prepared by the two methods showed that their molecular structures were identical.The reaction conditions,including solvents,ultrasonic power density and irradiation time,pH,and reactant ratio,were optimized by orthogonal design.A shorter reaction time and a higher product yield were obtained using ultrasonic-assisted synthesis compared with the traditional method.A condensation degree of 89.63% was achieved using the optimized conditions:i.e.ultrasonic irradiation at 180 W for 60 min;95% ethanol as the solvent,pH 4.0,and salicylaldehyde:chitosan ratio of 6:1.
文摘An efficient, environmentally friendly procedure is developed for the condensation of aldchydcs/kctoncs and activated methylene compounds by using an aminopropyl-functionalized MCM-41 catalyst in aqueous solution. Different aldchydcs/kctoncs and activated methylene compounds gave the corresponding alkcncs in 78-97% isolated yields in mild reaction conditions. In comparison with organic solution, the aqueous solution gives higher yields in the same reaction conditions. Further more, the aminopropyl-functionalizcd MCM-41 in aqueous system can be reused for 8 flints without significant decrease of activity.
文摘Three kind of aryl-substituted tri-benzyl sulfonium salts [ （4-phX）phSph2 ] PF6 [ X = S, O ] were prepared by the condensation of biphenyl sulfoxide with biphenyl sulfide, biphenyl ether or 1, 1＇ -biphenyl in the presence of polyphosphoric acid which can be used as dehydrate agent. The reaction condition was mild, such as reaction temperature between 40- 50 ℃ ,reactive time 2- 3 h, the yield of 4-（phenylthio）triphenylsulfonium hexafluorophosphate was 87.6%. The three kind sulfonium salts show better curing character to epoxy resin.
