A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the pr...A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the properties of reaction-controlled phasetransfer catalysis, and they had excellent catalytic ability to the oxidation of benzyl alcohol. No other by-products were detected by gas chromatography. Once the hydrogen peroxide was consumed completely, the catalyst precipitated from solvent, and the results of the catalyst recycle showed that the catalyst had high stability.展开更多
A new reaction-controlled phase-transfer catalyst system was designed and synthesized. In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxida...A new reaction-controlled phase-transfer catalyst system was designed and synthesized. In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxidant. The conversion of H2O2 was 100% and the yield of cyclohexene oxide was 87.1% based on cyclohexene. Infrared spectra showed that both fresh catalyst and the recovered catalyst do have completely same absorption peak, indicating the structure of catalyst is very stability and can be recycled.展开更多
Under the condition of solid-liquid phase transfer catalysis, olefins were obtained by the reaction of p-nitrobenzyldibutyltelluronium bromide with aromatic aldehyde.Under the condition of liquid-liquid phase transfer...Under the condition of solid-liquid phase transfer catalysis, olefins were obtained by the reaction of p-nitrobenzyldibutyltelluronium bromide with aromatic aldehyde.Under the condition of liquid-liquid phase transfer catalysis,however,different products were obtained due to the reactivity of different bases or aldehydes.展开更多
The phase transfer catalytic (PTC) bis-Wittig reaction between substitutedbenzaldehyde and 1,2- and 1,3-bisylides in the presence of K2Co3 was discussed.
9-Chlorofluorene reacted with aromatic aldehydes and ketones in the presence of phase transfer catalyst, giving the Darzens condensation epoxy products.
A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N（CH3）3]3 {PO4[MoO（O2）2]4} was utilized as the...A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N（CH3）3]3 {PO4[MoO（O2）2]4} was utilized as the reaction-controlled phase-transfer catalyst to catalyze oxidation of benzyl and aliphatic alcohols. The molar ratio of H2O2 and alcohol was 0.75, no other by-products were detected by gas chromatography, the results of oxidation reaction indicated that the catalyst has high activity and stability.展开更多
Using galvinoxyl as catalyst, the phase transfer catalyzed method of oxidation of primary amines to symmetrical azobenzenes with a saturated solution of potassium ferricyanide in 2 mom aqueous potassium hydroxide and ...Using galvinoxyl as catalyst, the phase transfer catalyzed method of oxidation of primary amines to symmetrical azobenzenes with a saturated solution of potassium ferricyanide in 2 mom aqueous potassium hydroxide and dichloromethane is described. The reaction has intimate relation with Hammett substituent constants. This report offers an efficient and rapid method to prepare azobenzenes and a possible mechanism is also suggested.展开更多
A chloromethylated styrene-divinylbenzene copolymer support system functionalized with 4-benzaldehyde and 2-benzaldehyde was prepared. The degree of functionalization with aldehyde groups is well suited for the subseq...A chloromethylated styrene-divinylbenzene copolymer support system functionalized with 4-benzaldehyde and 2-benzaldehyde was prepared. The degree of functionalization with aldehyde groups is well suited for the subsequent use of the products as Wittig reagents. The polymer bound aldehyde was reacted with Wittig reagents to give olefin groups grafted on styrene-divinylbenzene copolymers. The reactions were carded out in phase transfer catalysis conditions. A simple procedure for the calculation of the degree of functionalization and the statistical modeling of the structural repetitive unit of the copolymer are reported.展开更多
A series of novel catalysts was developed using cationic Gemini surfactants intercalated in natural montmorillonite (MMT) clay. These Gemini surfactant-MMT intercalates were used to study the kinetics of a nucleophili...A series of novel catalysts was developed using cationic Gemini surfactants intercalated in natural montmorillonite (MMT) clay. These Gemini surfactant-MMT intercalates were used to study the kinetics of a nucleophilic displacement reactions converting n-butyl bromide to n-butyl chloride in a triphase catalytic (TC) system. Most reaction rates compared favorably to those of biphase catalytic reactions where Gemini surfactants were used in the absence of MMT. Catalytic activity varied with Gemini surfactant structure, specifically with carbon spacer group and side chain length. In addition to the ease of catalyst separation that a triphase system affords, Gemini-MMT catalysts are stable and can be recycled and re-used several times.展开更多
Cross-linked poly（diallyldimethylammonium chloride） and its derivative copolymers were synthesized and used as phase transfer catalyst in the nucleophilic substitution reaction especially halogen exchange reactions....Cross-linked poly（diallyldimethylammonium chloride） and its derivative copolymers were synthesized and used as phase transfer catalyst in the nucleophilic substitution reaction especially halogen exchange reactions.In addition,the effect of hydrophilic-hydrophobic character of the polymers in the nucleophilic reactions was investigated.展开更多
A new reaction-controlled phase-transfer catalyst system, lacunary Keggin polyoxotungstate [C7H7N(CH3)3]9PW9O34 has been synthesized and used for catalytic epoxidation of olefins with H2O2 as t...A new reaction-controlled phase-transfer catalyst system, lacunary Keggin polyoxotungstate [C7H7N(CH3)3]9PW9O34 has been synthesized and used for catalytic epoxidation of olefins with H2O2 as the oxidant. Infrared spectra were used to analyze the behavior of the phase transfer of catalyst. In this system, the catalyst not only can act as homogeneous catalyst but also as heterogeneous catalyst to be easily filtered and reused. The epoxi- dation reaction is clean and exhibits high conversion and selectivity as well as excellent catalyst stability.展开更多
Dicyandiamide (cyanoguanidine) is widely used in the syntheses of melamine and medicines such as barbiturates and guanidine derivatives. However, the substitution reaction of dicyandiamide, particularly the tetra subs...Dicyandiamide (cyanoguanidine) is widely used in the syntheses of melamine and medicines such as barbiturates and guanidine derivatives. However, the substitution reaction of dicyandiamide, particularly the tetra substitution reaction, has not been reported so far. We report here the substitution reaction of dicyandiamide in the presence of phase transfer catalyst.展开更多
Ⅰ. INTRODUCTIONWittig reaction has been widely used in the syntheses of insect pheromones. However, the conventional route is not suitable for large-scale syntheses because it is hard to operate. The successful appli...Ⅰ. INTRODUCTIONWittig reaction has been widely used in the syntheses of insect pheromones. However, the conventional route is not suitable for large-scale syntheses because it is hard to operate. The successful application of phasc transfer catalysis makes the operation of Wittig reaction markedly convenient. At prcsent more investigations on PTC Wittig reaction have bccn reported. But almost all arc on the PTC展开更多
The asymmetric nitro-Mannich reaction is one of the traditional methods for forming carbon-carbon bond. By this reaction, the corresponding products with two contiguous stereocenters containing nitrogen substituents c...The asymmetric nitro-Mannich reaction is one of the traditional methods for forming carbon-carbon bond. By this reaction, the corresponding products with two contiguous stereocenters containing nitrogen substituents can be obtained. These β-nitro amine products can be easily transformed into 1,2-diamines by reduction of the corresponding nitro groups by means of the Nef reaction. It is well known that chiral 1,2-diamines Nay an important role in many fields.展开更多
文摘A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the properties of reaction-controlled phasetransfer catalysis, and they had excellent catalytic ability to the oxidation of benzyl alcohol. No other by-products were detected by gas chromatography. Once the hydrogen peroxide was consumed completely, the catalyst precipitated from solvent, and the results of the catalyst recycle showed that the catalyst had high stability.
文摘A new reaction-controlled phase-transfer catalyst system was designed and synthesized. In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxidant. The conversion of H2O2 was 100% and the yield of cyclohexene oxide was 87.1% based on cyclohexene. Infrared spectra showed that both fresh catalyst and the recovered catalyst do have completely same absorption peak, indicating the structure of catalyst is very stability and can be recycled.
文摘Under the condition of solid-liquid phase transfer catalysis, olefins were obtained by the reaction of p-nitrobenzyldibutyltelluronium bromide with aromatic aldehyde.Under the condition of liquid-liquid phase transfer catalysis,however,different products were obtained due to the reactivity of different bases or aldehydes.
文摘The phase transfer catalytic (PTC) bis-Wittig reaction between substitutedbenzaldehyde and 1,2- and 1,3-bisylides in the presence of K2Co3 was discussed.
文摘9-Chlorofluorene reacted with aromatic aldehydes and ketones in the presence of phase transfer catalyst, giving the Darzens condensation epoxy products.
文摘A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N（CH3）3]3 {PO4[MoO（O2）2]4} was utilized as the reaction-controlled phase-transfer catalyst to catalyze oxidation of benzyl and aliphatic alcohols. The molar ratio of H2O2 and alcohol was 0.75, no other by-products were detected by gas chromatography, the results of oxidation reaction indicated that the catalyst has high activity and stability.
文摘Using galvinoxyl as catalyst, the phase transfer catalyzed method of oxidation of primary amines to symmetrical azobenzenes with a saturated solution of potassium ferricyanide in 2 mom aqueous potassium hydroxide and dichloromethane is described. The reaction has intimate relation with Hammett substituent constants. This report offers an efficient and rapid method to prepare azobenzenes and a possible mechanism is also suggested.
文摘A chloromethylated styrene-divinylbenzene copolymer support system functionalized with 4-benzaldehyde and 2-benzaldehyde was prepared. The degree of functionalization with aldehyde groups is well suited for the subsequent use of the products as Wittig reagents. The polymer bound aldehyde was reacted with Wittig reagents to give olefin groups grafted on styrene-divinylbenzene copolymers. The reactions were carded out in phase transfer catalysis conditions. A simple procedure for the calculation of the degree of functionalization and the statistical modeling of the structural repetitive unit of the copolymer are reported.
文摘A series of novel catalysts was developed using cationic Gemini surfactants intercalated in natural montmorillonite (MMT) clay. These Gemini surfactant-MMT intercalates were used to study the kinetics of a nucleophilic displacement reactions converting n-butyl bromide to n-butyl chloride in a triphase catalytic (TC) system. Most reaction rates compared favorably to those of biphase catalytic reactions where Gemini surfactants were used in the absence of MMT. Catalytic activity varied with Gemini surfactant structure, specifically with carbon spacer group and side chain length. In addition to the ease of catalyst separation that a triphase system affords, Gemini-MMT catalysts are stable and can be recycled and re-used several times.
文摘Cross-linked poly（diallyldimethylammonium chloride） and its derivative copolymers were synthesized and used as phase transfer catalyst in the nucleophilic substitution reaction especially halogen exchange reactions.In addition,the effect of hydrophilic-hydrophobic character of the polymers in the nucleophilic reactions was investigated.
基金Project supported by the National Natural 863 Plan of China (No. 2001AA33440203).
文摘A new reaction-controlled phase-transfer catalyst system, lacunary Keggin polyoxotungstate [C7H7N(CH3)3]9PW9O34 has been synthesized and used for catalytic epoxidation of olefins with H2O2 as the oxidant. Infrared spectra were used to analyze the behavior of the phase transfer of catalyst. In this system, the catalyst not only can act as homogeneous catalyst but also as heterogeneous catalyst to be easily filtered and reused. The epoxi- dation reaction is clean and exhibits high conversion and selectivity as well as excellent catalyst stability.
文摘Dicyandiamide (cyanoguanidine) is widely used in the syntheses of melamine and medicines such as barbiturates and guanidine derivatives. However, the substitution reaction of dicyandiamide, particularly the tetra substitution reaction, has not been reported so far. We report here the substitution reaction of dicyandiamide in the presence of phase transfer catalyst.
文摘Ⅰ. INTRODUCTIONWittig reaction has been widely used in the syntheses of insect pheromones. However, the conventional route is not suitable for large-scale syntheses because it is hard to operate. The successful application of phasc transfer catalysis makes the operation of Wittig reaction markedly convenient. At prcsent more investigations on PTC Wittig reaction have bccn reported. But almost all arc on the PTC
基金Supported by the National Natural Science Foundation of China（No. 51373067）.
文摘The asymmetric nitro-Mannich reaction is one of the traditional methods for forming carbon-carbon bond. By this reaction, the corresponding products with two contiguous stereocenters containing nitrogen substituents can be obtained. These β-nitro amine products can be easily transformed into 1,2-diamines by reduction of the corresponding nitro groups by means of the Nef reaction. It is well known that chiral 1,2-diamines Nay an important role in many fields.
