Four types of chiral thiazolidine derivatives were synthesized conveniently from natural L-cysteine and showed good enantioselectivity in up to 90% ee in the addition of diethylzine to benzaldehyde. Their enantioselec...Four types of chiral thiazolidine derivatives were synthesized conveniently from natural L-cysteine and showed good enantioselectivity in up to 90% ee in the addition of diethylzine to benzaldehyde. Their enantioselectivity was affected by the bulkiness of R and the thiazolidine ring systems in their molecules.展开更多
Both enantiomers R-1 and S-1 of a chiral C60 derivative were synthesized by the reactions of C60 with 1, 1'-bi-2-naphthol bis(azidoacetates) and characterized by FD-MS, fT-IR,1H NMR, 13C NMR, UV-VIS, CD spectra.
A novel β-cyclodextrin derivative, 2, 6-di-O-butyl-3-O-acetyl-β-cyclodex- trin, was prepared and used as chiral stationary phase for capillary gas chromato- graphic resolution of enantiomers, lhe glass capillary col...A novel β-cyclodextrin derivative, 2, 6-di-O-butyl-3-O-acetyl-β-cyclodex- trin, was prepared and used as chiral stationary phase for capillary gas chromato- graphic resolution of enantiomers, lhe glass capillary columns with the derivative having low melting point and high thermal stability could produce more than 3000 plates per column meter and have proven to be good chlral columns to separate the enantiomers of some amino acids, derivatives of epoxy ethane and alkyl halide, etc.展开更多
The cyclizations of L-(+)-prolinol 1 derived from L-proline with (thio)phosphoro(-no)dichlorides 2 give 1,2,3-azaphosphaoxabicyclo[3.3.0] 3 consisting of unequal amounts of diastereoisomers, eight pairs of which have ...The cyclizations of L-(+)-prolinol 1 derived from L-proline with (thio)phosphoro(-no)dichlorides 2 give 1,2,3-azaphosphaoxabicyclo[3.3.0] 3 consisting of unequal amounts of diastereoisomers, eight pairs of which have been successfully separated by silica gel column chromatography or recrystallization.展开更多
Racemic O-methyl O-pheayl thiophosphoric acid 1 has been successfully resolved through its quinine and brucine salts in methanol solution by fractional crystallization. The absolute configurations of the optically act...Racemic O-methyl O-pheayl thiophosphoric acid 1 has been successfully resolved through its quinine and brucine salts in methanol solution by fractional crystallization. The absolute configurations of the optically active 1 have been established as (+)-R-1 and (-)-S-1 by chemical correlation.展开更多
Six new kinds of amino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl amino)-2-(hydroxy)...Six new kinds of amino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl amino)-2-(hydroxy) propyl]}-β-cyclodextrin (i.e. L-Val-β-CD), heptakis{2,6-di-O-[3-L-(1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Phe-β-CD), heptakis{2,6-di-O-[3-(D, L-1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. D,L-Phe-β-CD), heptakis{2,6-di-O-[3-(L-1-hydroxymethyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Ser-β-CD), heptakis{2,6-di-O-[3-(L-1-carboxylmethyl carboxyl methyl amino)- 2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Asp-β-CD), heptakis{2,6-di-O-[3-(L-2-carboxyl tetramethylene amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Pro-β-CD). Their chemical structures were certified using FTIR and ()~1H NMR. Except for L-Phe-β-CD and D,L-Phe-β-CD, that are in soluble in water, the other amino acid derived β-CDs all have good water solubility. D,L-tyrosine and promethazine were baselinely separated by L-Val-β-CD in capillary electrophoresis.展开更多
A chiral phosphorous derivatizing agent prepared from PCl3 and (S)-BINOL was described. It is used to determine the enantiomeric excess of chiral alcohols and amines by 31P NMR.
Bosonic part of SU(2)L U(1)Y effective chiral Lagrangian for electroweak symmetry breaking is derived from an underlying technicolor theory with no approximation. The underlying theory is assumed to be the most genera...Bosonic part of SU(2)L U(1)Y effective chiral Lagrangian for electroweak symmetry breaking is derived from an underlying technicolor theory with no approximation. The underlying theory is assumed to be the most general gauge theory without fundamental scalars. A condensate is required to exist in the theory which breaks SU(2)L U(1)Y dynamically to U(1)em and the anomaly of the theory caused by gauge interaction must be cancelled. The formulation offers general definitions in terms of underlying theory for the low energy constants in effective chiral Lagrangian.展开更多
Three novel chiral selectors 4a-c were synthesized from （S）-amino acids and （R）-1-phenyl-2-（4-methylphenyl）ethylamine. 4a-c were connected to 3-aminopropylsilanized silica gel to be used as the chiral stationary...Three novel chiral selectors 4a-c were synthesized from （S）-amino acids and （R）-1-phenyl-2-（4-methylphenyl）ethylamine. 4a-c were connected to 3-aminopropylsilanized silica gel to be used as the chiral stationary phase for HPLC. Five amino acid derivatives and two pyrethroid insecticides were fairly resolved on these three new chiral stationary phases under normal phase condition.展开更多
A novel chiral stationary phase （CSP） was prepared by immobilizing mono（6A-N-1-（2-hydroxyl）-phenylethylimino-6A- deoxy）-β-cyclodextrin onto the surface of silica gel via a longer spacer. This chiral stationary ...A novel chiral stationary phase （CSP） was prepared by immobilizing mono（6A-N-1-（2-hydroxyl）-phenylethylimino-6A- deoxy）-β-cyclodextrin onto the surface of silica gel via a longer spacer. This chiral stationary phase exhibited good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.展开更多
A novel chirality pairing recognition was found between D-and L-amino acid derivatives.Novel spiral alkaloids formed in the recognition reaction.Possible mechanism was proposed for the stereoselective and chemoselecti...A novel chirality pairing recognition was found between D-and L-amino acid derivatives.Novel spiral alkaloids formed in the recognition reaction.Possible mechanism was proposed for the stereoselective and chemoselective reactions.展开更多
Effective enantioseparation of Naftopidil and its derivatives by HPLC was accomplished using several different polysaccharide-based chiral stationary phases（CSPs）.In normal-phase mode,the compounds were eluted on fo...Effective enantioseparation of Naftopidil and its derivatives by HPLC was accomplished using several different polysaccharide-based chiral stationary phases（CSPs）.In normal-phase mode,the compounds were eluted on four coated-and two immobilized-columns with the mixture of n-hexane,isopropanol and diethylamine（DEA）.Polysaccharide tris（3,5- dimethylphenyl carbamate） was shown to be the best enantiomer selector.In addition,the immobilized column packed with Chiralpak IA or IB was applied under polar-organic and reversed-phase conditions,both of which exhibited excellent enantioselectivity for Naftopidil and its derivatives.Furthermore,the underlying possible chiral recognition mechanisms were discussed.展开更多
Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical ...Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical scale column packed with immobilized polysaccharide-based chiral stationary phases （CSPs）. We found that separation on the Chiralpak IA CSP was superior to the other two immobilized CSPs （Chiralpak IB and Chiralpak IC）, and isopropanol （IPA） was a superior modifier compared to the other five solvents including ethanol, methanol, tetrahydrofuran, acetonitrile and dichloromethane. The effects of organic modifier composition, back pressure, and column temperature for enantioseparation of all six compounds were studied. Of the physical parameters studied, modifier composition had the greatest impact on retention. Changing temperature generally had less impact on retention but produced the greatest selectivity changes. The optimum condition was found as follows： Chiralpak IA column, column temperature 35 ~C, back pressure 120 bar, 35% IPA containing 0.1% diethylamine （v/v） in mobile phase, flow rate of mobile phase 3.0 mL/min, UV detection 283 nm. Separation of all six racemic compounds was completed within 10 rain and excellent resolution was obtained. Thus, SFC was found to be the methodology of choice for resolving the enantiomers of this class of compounds.展开更多
基金This work was financially supported by the State Key Laboratory of Elemento-Organic Chemistry,Nankai University.
文摘Four types of chiral thiazolidine derivatives were synthesized conveniently from natural L-cysteine and showed good enantioselectivity in up to 90% ee in the addition of diethylzine to benzaldehyde. Their enantioselectivity was affected by the bulkiness of R and the thiazolidine ring systems in their molecules.
文摘Both enantiomers R-1 and S-1 of a chiral C60 derivative were synthesized by the reactions of C60 with 1, 1'-bi-2-naphthol bis(azidoacetates) and characterized by FD-MS, fT-IR,1H NMR, 13C NMR, UV-VIS, CD spectra.
文摘A novel β-cyclodextrin derivative, 2, 6-di-O-butyl-3-O-acetyl-β-cyclodex- trin, was prepared and used as chiral stationary phase for capillary gas chromato- graphic resolution of enantiomers, lhe glass capillary columns with the derivative having low melting point and high thermal stability could produce more than 3000 plates per column meter and have proven to be good chlral columns to separate the enantiomers of some amino acids, derivatives of epoxy ethane and alkyl halide, etc.
文摘The cyclizations of L-(+)-prolinol 1 derived from L-proline with (thio)phosphoro(-no)dichlorides 2 give 1,2,3-azaphosphaoxabicyclo[3.3.0] 3 consisting of unequal amounts of diastereoisomers, eight pairs of which have been successfully separated by silica gel column chromatography or recrystallization.
基金This project was supported by National Natural Science Foundation of China
文摘Racemic O-methyl O-pheayl thiophosphoric acid 1 has been successfully resolved through its quinine and brucine salts in methanol solution by fractional crystallization. The absolute configurations of the optically active 1 have been established as (+)-R-1 and (-)-S-1 by chemical correlation.
文摘Six new kinds of amino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl amino)-2-(hydroxy) propyl]}-β-cyclodextrin (i.e. L-Val-β-CD), heptakis{2,6-di-O-[3-L-(1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Phe-β-CD), heptakis{2,6-di-O-[3-(D, L-1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. D,L-Phe-β-CD), heptakis{2,6-di-O-[3-(L-1-hydroxymethyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Ser-β-CD), heptakis{2,6-di-O-[3-(L-1-carboxylmethyl carboxyl methyl amino)- 2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Asp-β-CD), heptakis{2,6-di-O-[3-(L-2-carboxyl tetramethylene amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Pro-β-CD). Their chemical structures were certified using FTIR and ()~1H NMR. Except for L-Phe-β-CD and D,L-Phe-β-CD, that are in soluble in water, the other amino acid derived β-CDs all have good water solubility. D,L-tyrosine and promethazine were baselinely separated by L-Val-β-CD in capillary electrophoresis.
基金We are very grateful for the financial support of the National Natural Science Foundation of China (No.29872016) and the Hong Kong Polytechnic University ASD Fund.
文摘A chiral phosphorous derivatizing agent prepared from PCl3 and (S)-BINOL was described. It is used to determine the enantiomeric excess of chiral alcohols and amines by 31P NMR.
文摘Bosonic part of SU(2)L U(1)Y effective chiral Lagrangian for electroweak symmetry breaking is derived from an underlying technicolor theory with no approximation. The underlying theory is assumed to be the most general gauge theory without fundamental scalars. A condensate is required to exist in the theory which breaks SU(2)L U(1)Y dynamically to U(1)em and the anomaly of the theory caused by gauge interaction must be cancelled. The formulation offers general definitions in terms of underlying theory for the low energy constants in effective chiral Lagrangian.
基金the National Natural Science Foundation of China （No. 20472111） is gratefully acknowledged.
文摘Three novel chiral selectors 4a-c were synthesized from （S）-amino acids and （R）-1-phenyl-2-（4-methylphenyl）ethylamine. 4a-c were connected to 3-aminopropylsilanized silica gel to be used as the chiral stationary phase for HPLC. Five amino acid derivatives and two pyrethroid insecticides were fairly resolved on these three new chiral stationary phases under normal phase condition.
基金Financial support from the National Natural Science Foundation of China (No.20572009)
文摘A novel chiral stationary phase （CSP） was prepared by immobilizing mono（6A-N-1-（2-hydroxyl）-phenylethylimino-6A- deoxy）-β-cyclodextrin onto the surface of silica gel via a longer spacer. This chiral stationary phase exhibited good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.
基金supports from NSFC(30873141)973 Program(2009CB522300)Hebei University and the State Key Laboratory of Phytochemistry and Plant Resources in West China.
文摘A novel chirality pairing recognition was found between D-and L-amino acid derivatives.Novel spiral alkaloids formed in the recognition reaction.Possible mechanism was proposed for the stereoselective and chemoselective reactions.
基金Guangzhou mega Projects of Science Research in 2009(Grant No.2009A1-E011-7)
文摘Effective enantioseparation of Naftopidil and its derivatives by HPLC was accomplished using several different polysaccharide-based chiral stationary phases（CSPs）.In normal-phase mode,the compounds were eluted on four coated-and two immobilized-columns with the mixture of n-hexane,isopropanol and diethylamine（DEA）.Polysaccharide tris（3,5- dimethylphenyl carbamate） was shown to be the best enantiomer selector.In addition,the immobilized column packed with Chiralpak IA or IB was applied under polar-organic and reversed-phase conditions,both of which exhibited excellent enantioselectivity for Naftopidil and its derivatives.Furthermore,the underlying possible chiral recognition mechanisms were discussed.
基金Science and Technology Program of Guangzhou City(Grant No.2010U1-E0531-2)
文摘Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical scale column packed with immobilized polysaccharide-based chiral stationary phases （CSPs）. We found that separation on the Chiralpak IA CSP was superior to the other two immobilized CSPs （Chiralpak IB and Chiralpak IC）, and isopropanol （IPA） was a superior modifier compared to the other five solvents including ethanol, methanol, tetrahydrofuran, acetonitrile and dichloromethane. The effects of organic modifier composition, back pressure, and column temperature for enantioseparation of all six compounds were studied. Of the physical parameters studied, modifier composition had the greatest impact on retention. Changing temperature generally had less impact on retention but produced the greatest selectivity changes. The optimum condition was found as follows： Chiralpak IA column, column temperature 35 ~C, back pressure 120 bar, 35% IPA containing 0.1% diethylamine （v/v） in mobile phase, flow rate of mobile phase 3.0 mL/min, UV detection 283 nm. Separation of all six racemic compounds was completed within 10 rain and excellent resolution was obtained. Thus, SFC was found to be the methodology of choice for resolving the enantiomers of this class of compounds.
