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1997 Volume 8 Issue 5
1997, 8(5): 361-364
Abstract:
The phase transfer catalytic (PTC) bis-Wittig reaction between substituted benzaldehyde and 1,2-and 1,3-bisylides in the presence of K2CO3 was discussed.
The phase transfer catalytic (PTC) bis-Wittig reaction between substituted benzaldehyde and 1,2-and 1,3-bisylides in the presence of K2CO3 was discussed.
1997, 8(5): 365-366
Abstract:
A series of enantiomerically pure (4R,5R)-(-)-4-alkyloxy-5-[(1R,2S,5R)-menthyloxy]-3,4-dihydro-2(5H)-furanones (2) have been synthesized in excellent yields via asymmetric conjugate additions of primary alcohols to (R)-(-)-5-[(1R,2S,5R)-menthyloxy]-2(5H)-furanone (1) in the presence of a catalytic amount of sodium in DMF,which provides access to new multifunctional homochiral building blocks,optically pure (R) or (S)-2-alkyloxy-1,4-butanediols (3).
A series of enantiomerically pure (4R,5R)-(-)-4-alkyloxy-5-[(1R,2S,5R)-menthyloxy]-3,4-dihydro-2(5H)-furanones (2) have been synthesized in excellent yields via asymmetric conjugate additions of primary alcohols to (R)-(-)-5-[(1R,2S,5R)-menthyloxy]-2(5H)-furanone (1) in the presence of a catalytic amount of sodium in DMF,which provides access to new multifunctional homochiral building blocks,optically pure (R) or (S)-2-alkyloxy-1,4-butanediols (3).
1997, 8(5): 367-368
Abstract:
α,α'-Dioxo (ester) ketene cyclic S,S-acetals 2 were reacted with ethylenediamine to afford α,α'-dioxo (ester) ketene cyclic N,N-acetals 3.This process provides a new method for the synthesis of 3 in good yield under mild condition.All products are confirmed with elemental analysis,IR,1H NMR and 13C NMR.
α,α'-Dioxo (ester) ketene cyclic S,S-acetals 2 were reacted with ethylenediamine to afford α,α'-dioxo (ester) ketene cyclic N,N-acetals 3.This process provides a new method for the synthesis of 3 in good yield under mild condition.All products are confirmed with elemental analysis,IR,1H NMR and 13C NMR.
1997, 8(5): 369-372
Abstract:
Glycosylation of calix[4]arenes with α-acetobromoglucopyranoside 1 in acetonitrile in the presence of potassium carbonate or calcium hydride under mild conditions gave sugar calix[4]arenes 4 and 5 in good yields,and β-anomers were the sole products with high stereoselectivity.Compound 4 or 5 were dealt with ammonia in methyl alcohol to afford the water-soluble calix[4]arenes derivatives 6 and 7.
Glycosylation of calix[4]arenes with α-acetobromoglucopyranoside 1 in acetonitrile in the presence of potassium carbonate or calcium hydride under mild conditions gave sugar calix[4]arenes 4 and 5 in good yields,and β-anomers were the sole products with high stereoselectivity.Compound 4 or 5 were dealt with ammonia in methyl alcohol to afford the water-soluble calix[4]arenes derivatives 6 and 7.
1997, 8(5): 373-374
Abstract:
2-p-Anisyl-4-methoxy-5-hydroxybenzofuran was synthesized via intramolecular Wittig reaction between the phosphonium salt and the ester in the presence of triethylamine.Its 1H-NMR was very similar to that of Gnetifolin A.Thus the revised structure of Gnetifolin A can be considered to be strongly confirmed.
2-p-Anisyl-4-methoxy-5-hydroxybenzofuran was synthesized via intramolecular Wittig reaction between the phosphonium salt and the ester in the presence of triethylamine.Its 1H-NMR was very similar to that of Gnetifolin A.Thus the revised structure of Gnetifolin A can be considered to be strongly confirmed.
1997, 8(5): 375-376
Abstract:
Ion/molecule reactions of C60 with vinyl acetate under chemical ionization conditions have been studied here.Compared with C2H3O- from acetone. C2H3O- from vinyl acetate undergoes the reactions more easily,a new heterocycle between C60 and the studied ion is formed.The generation of two σ-bonds and little angle tensile force of pentatomic ring make it more stable.
Ion/molecule reactions of C60 with vinyl acetate under chemical ionization conditions have been studied here.Compared with C2H3O- from acetone. C2H3O- from vinyl acetate undergoes the reactions more easily,a new heterocycle between C60 and the studied ion is formed.The generation of two σ-bonds and little angle tensile force of pentatomic ring make it more stable.
1997, 8(5): 377-380
Abstract:
The acetalization of a series of carbonyl compounds with ethanediol was performed over two self-steamed HY zeolite catalysts.The acetal and ketal products were obtained with high yields.Especially,the HY zeolite with high framework Si/Al ratio was proven to be suitable catalyst for the acetalization of unsaturated carbonyl compounds,during which the C=C double bond was not perturbed.
The acetalization of a series of carbonyl compounds with ethanediol was performed over two self-steamed HY zeolite catalysts.The acetal and ketal products were obtained with high yields.Especially,the HY zeolite with high framework Si/Al ratio was proven to be suitable catalyst for the acetalization of unsaturated carbonyl compounds,during which the C=C double bond was not perturbed.
1997, 8(5): 381-384
Abstract:
The synthesis of phenothiazine and phenoxthine was performed very efficiently through the thionation of diphenylamine and diphenyl ether,respectively,with elemental sulfur by using hydrothermally treated HY zeolites as catalysts.The nature of the active sites of the zeolites for the thionation reaction was discussed.
The synthesis of phenothiazine and phenoxthine was performed very efficiently through the thionation of diphenylamine and diphenyl ether,respectively,with elemental sulfur by using hydrothermally treated HY zeolites as catalysts.The nature of the active sites of the zeolites for the thionation reaction was discussed.
1997, 8(5): 385-386
Abstract:
Spin labeled PNAT10 was synthesized by solid phase method with Boc strategy.The product was characterized by ESR and TOF MS analysis revealing a facile spin labeling of PNA by in situ solid phase synthesis.
Spin labeled PNAT10 was synthesized by solid phase method with Boc strategy.The product was characterized by ESR and TOF MS analysis revealing a facile spin labeling of PNA by in situ solid phase synthesis.
1997, 8(5): 387-388
Abstract:
Two imidazolium bis-estrogens as a new type of biomimetic model,which possess potential multiple biomimetic functions,were synthesized in good yields by three steps from estrogen.All new compounds were characterized by MS,1HNMR and elemental analysis.
Two imidazolium bis-estrogens as a new type of biomimetic model,which possess potential multiple biomimetic functions,were synthesized in good yields by three steps from estrogen.All new compounds were characterized by MS,1HNMR and elemental analysis.
1997, 8(5): 389-392
Abstract:
Synthesis of five 7-membered compounds containing silane,sulfur and phosphorus groups was achieved by using endo,endo-bicyclo[3.3.0]octanediol 2.These tricyclic molecules are considered as ideal substrates for kinetic resolution of the diol.A discussion of the spectral data about these compounds was given and four of them would be substrate molecules containing an sp3 hybridized prochiral center and could be used for molecules for a kinetic resolution combining configurational diastereotopos-differentiating and diastereoisomer-differentiating reactions.
Synthesis of five 7-membered compounds containing silane,sulfur and phosphorus groups was achieved by using endo,endo-bicyclo[3.3.0]octanediol 2.These tricyclic molecules are considered as ideal substrates for kinetic resolution of the diol.A discussion of the spectral data about these compounds was given and four of them would be substrate molecules containing an sp3 hybridized prochiral center and could be used for molecules for a kinetic resolution combining configurational diastereotopos-differentiating and diastereoisomer-differentiating reactions.
1997, 8(5): 393-396
Abstract:
Four imidazole cyclophanes have been synthesized by the oxidation of bis-imidazoline with barium manganate followed by cyclization with 2,6-bis(bromomethyl) pyridine in the presence of NaH.All the compounds were identified by IR,1HNMR,MS and elemental analysis.
Four imidazole cyclophanes have been synthesized by the oxidation of bis-imidazoline with barium manganate followed by cyclization with 2,6-bis(bromomethyl) pyridine in the presence of NaH.All the compounds were identified by IR,1HNMR,MS and elemental analysis.
1997, 8(5): 397-400
Abstract:
The reactions of 2-chloro-1,3,2-dioxaphospholane with various sodium salts of amino acids to afford the pentacoordinated spirophosphoranes containing amino acid were studied by NMR spectra techniques.The results showed that natural α-amino acids had greater ability than β-amino acids to form the pentacoordinated species,which is important in the biosynthesis and prebiotic synthesis of oligopeptides and proteins.
The reactions of 2-chloro-1,3,2-dioxaphospholane with various sodium salts of amino acids to afford the pentacoordinated spirophosphoranes containing amino acid were studied by NMR spectra techniques.The results showed that natural α-amino acids had greater ability than β-amino acids to form the pentacoordinated species,which is important in the biosynthesis and prebiotic synthesis of oligopeptides and proteins.
1997, 8(5): 401-402
Abstract:
Two kinds of vanadyl nucleotide were synthesized from vanadyl trichloride with adenosine derivatives.
Two kinds of vanadyl nucleotide were synthesized from vanadyl trichloride with adenosine derivatives.
1997, 8(5): 403-406
Abstract:
Two types of eight kinds of new squarains were designed and synthesized.Their structures were elucidated by IR,NMR,MS and elementary analysis.Their luminescent properties were determined,which indicated that they can be used as organic electroluminescent materials.
Two types of eight kinds of new squarains were designed and synthesized.Their structures were elucidated by IR,NMR,MS and elementary analysis.Their luminescent properties were determined,which indicated that they can be used as organic electroluminescent materials.
1997, 8(5): 407-410
Abstract:
The 1,3-distally selective functionalization of calix[4]arenes with benzylic bromides at the lower rim in excellent yields is described.The calix[4]arenes with dendritic fragments obtained exist in cone conformation.
The 1,3-distally selective functionalization of calix[4]arenes with benzylic bromides at the lower rim in excellent yields is described.The calix[4]arenes with dendritic fragments obtained exist in cone conformation.
1997, 8(5): 411-412
Abstract:
An efficient total synthesis of (±)-3-(5-hydroxy-4-methyl-7-isopropyl-3E,7-octadienyl)-△2-butenolide,a new farnesane-based homosesquiterpene lactone.starting from geraniol through eight steps are described.
An efficient total synthesis of (±)-3-(5-hydroxy-4-methyl-7-isopropyl-3E,7-octadienyl)-△2-butenolide,a new farnesane-based homosesquiterpene lactone.starting from geraniol through eight steps are described.
1997, 8(5): 413-416
Abstract:
Kinetic resolution of DL-phenylalanine methyl ester was carried out using immobilized α-chymotrypsin (IC) as catalyst.The effects of temperature,pH,concentration of substrate and reaction vessels on the resolution were investigated.High quality L-phenylalanine was obtained in good yield by an IC column.
Kinetic resolution of DL-phenylalanine methyl ester was carried out using immobilized α-chymotrypsin (IC) as catalyst.The effects of temperature,pH,concentration of substrate and reaction vessels on the resolution were investigated.High quality L-phenylalanine was obtained in good yield by an IC column.
1997, 8(5): 417-418
Abstract:
Using oleyl alcohol as carbon source for the cultivation of yeast Torulopsis sp.,a modified sophorose lipid was isolated as the major product.This product was characterized as the octadecyl derivative by 1H NMR and FAB-MS.Hydrogenation gave an octadecyl ester:octadecyl 17-L-[(2'-o-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] octadecanoate 6',6"-diacetate.
Using oleyl alcohol as carbon source for the cultivation of yeast Torulopsis sp.,a modified sophorose lipid was isolated as the major product.This product was characterized as the octadecyl derivative by 1H NMR and FAB-MS.Hydrogenation gave an octadecyl ester:octadecyl 17-L-[(2'-o-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] octadecanoate 6',6"-diacetate.
1997, 8(5): 419-420
Abstract:
A new ceramide sertularamide was isolated from the alga Caulerpa sertularioides collected from the South China Sea and its structure was established by spectroscopic methods.
A new ceramide sertularamide was isolated from the alga Caulerpa sertularioides collected from the South China Sea and its structure was established by spectroscopic methods.
1997, 8(5): 421-424
Abstract:
From the dried leaves of I.eriocalyx,three new 6,7-seco-ent-kaurane diterpenoids epi-eriocalyxin A (2),maoecrystal N (3) and maoecrystal O (4) were isolated.Meanwhile,the structure of a known constituent eriocalyxin A was revised.
From the dried leaves of I.eriocalyx,three new 6,7-seco-ent-kaurane diterpenoids epi-eriocalyxin A (2),maoecrystal N (3) and maoecrystal O (4) were isolated.Meanwhile,the structure of a known constituent eriocalyxin A was revised.
1997, 8(5): 425-426
Abstract:
A novel high sensitivity,small-volume photothermal interference detector has been introduced for capillary zone electrophoresis separation analysis.The utility of this simultaneous technique for monitoring chelating reaction of light rare earth with tribromoarsenazo has been reported.
A novel high sensitivity,small-volume photothermal interference detector has been introduced for capillary zone electrophoresis separation analysis.The utility of this simultaneous technique for monitoring chelating reaction of light rare earth with tribromoarsenazo has been reported.
1997, 8(5): 427-430
Abstract:
A single-sweep oscillopolarographic procedure is described which allows determination of rate constants for reactions of OH.For a wide range of compounds,the results fit well with rate constants previously obtained with other methods.Rate constants for reactions of six kinds of active compounds contained in rheum,a traditional Chinese herb,have been determined by this method.Reaction mechanism has also been discussed.
A single-sweep oscillopolarographic procedure is described which allows determination of rate constants for reactions of OH.For a wide range of compounds,the results fit well with rate constants previously obtained with other methods.Rate constants for reactions of six kinds of active compounds contained in rheum,a traditional Chinese herb,have been determined by this method.Reaction mechanism has also been discussed.
1997, 8(5): 431-434
Abstract:
Surfactants(S) induced room-temperature phosphorescence(RTP) from 1-bromonaphthalene(1-BrN) in aerated aqueous solutions of β-cyclodextrin(β-CD) has been investigated in detail.It has been found that the partial inclusion and coil of hydrocarbon chain of surfactants at the mouth of the β-CD cavity is responsible for bright RTP.
Surfactants(S) induced room-temperature phosphorescence(RTP) from 1-bromonaphthalene(1-BrN) in aerated aqueous solutions of β-cyclodextrin(β-CD) has been investigated in detail.It has been found that the partial inclusion and coil of hydrocarbon chain of surfactants at the mouth of the β-CD cavity is responsible for bright RTP.
1997, 8(5): 435-436
Abstract:
The metal vapor synthesis (MVS) methed was used to prepare activated carbon supported nickel electrode.The electrocatalytic activity of the electrode for hydrogen evolution reaction (HGR) in alkaline solution was studied.Cathodic polarization curves showed the electrocatalytic activity of Ni/C electrode prepared by MVS method was higher than that of the one prepared by conventional method.
The metal vapor synthesis (MVS) methed was used to prepare activated carbon supported nickel electrode.The electrocatalytic activity of the electrode for hydrogen evolution reaction (HGR) in alkaline solution was studied.Cathodic polarization curves showed the electrocatalytic activity of Ni/C electrode prepared by MVS method was higher than that of the one prepared by conventional method.
1997, 8(5): 437-438
Abstract:
The microporous nanocrystalline TiO2 electrode with large surface roughness factor has been prepared on a conducting glass support.Modification of the TiO2 electrode by in situ preparing quantum sized RuS2 particles on the surface of TiO2 electrode extends the optical absorption spectrum and photocurrent action spectrum into visible region.In addition,compared with RuS2 bulk materials,a blue shift in both absorption spectrum and photocurrent action spectrum of RuS2/TiO2 electrode is observed and explained in terms of quantum sized effect.
The microporous nanocrystalline TiO2 electrode with large surface roughness factor has been prepared on a conducting glass support.Modification of the TiO2 electrode by in situ preparing quantum sized RuS2 particles on the surface of TiO2 electrode extends the optical absorption spectrum and photocurrent action spectrum into visible region.In addition,compared with RuS2 bulk materials,a blue shift in both absorption spectrum and photocurrent action spectrum of RuS2/TiO2 electrode is observed and explained in terms of quantum sized effect.
1997, 8(5): 439-442
Abstract:
The microscopic molecular theory for electron transfer in a model solvent is further developed.The nonlinear response of the solvent molecules is be computed quantitatively in a new way.Adopting computer simulation data and choosing appropriate reaction coordinate,a reasonable free energy diagram is constructed and the reorganization energy for the product state is calculated.
The microscopic molecular theory for electron transfer in a model solvent is further developed.The nonlinear response of the solvent molecules is be computed quantitatively in a new way.Adopting computer simulation data and choosing appropriate reaction coordinate,a reasonable free energy diagram is constructed and the reorganization energy for the product state is calculated.
1997, 8(5): 443-446
Abstract:
Four micro states of Fe-CO with 3dσ-4s and 3dδ-3dδ electrons spin-paired or unpaired are examined to investigate the influence of pairing versus unpairing mechanism upon the bondings and interactions in Fe-CO.The calculation results show that the Fe-CO bondings and interactions are determined by a balance between the bonding stabilization and the exchange stabilization with or without 3dσ-4s electron spin-pairing.The 3dδ-3dδ electron spin-pairing versus unpairing has a surprising large effect on the Fe-CO bonding properties,even though the 3dδ orbitals are usually considered as being nonbonding.
Four micro states of Fe-CO with 3dσ-4s and 3dδ-3dδ electrons spin-paired or unpaired are examined to investigate the influence of pairing versus unpairing mechanism upon the bondings and interactions in Fe-CO.The calculation results show that the Fe-CO bondings and interactions are determined by a balance between the bonding stabilization and the exchange stabilization with or without 3dσ-4s electron spin-pairing.The 3dδ-3dδ electron spin-pairing versus unpairing has a surprising large effect on the Fe-CO bonding properties,even though the 3dδ orbitals are usually considered as being nonbonding.
1997, 8(5): 447-450
Abstract:
The optical properties of C60 chemically modified polystyrene (C60-PS copolymer) and the parent polystyrene (PS) films have been investigated.Addition of bulky C60 moiety,a special functional group,to the polystyrene by a novel organometallic reaction modified considerably the optical property of the parent polystyrene.The lattice periodicity of pure PS film is subject to some perturbation or distortion in varying degrees due to the covalent attachment of bulky C60 moiety to the polymer backbone.C60-PS copolymer possesses a new energy band structure with indirect forbidden band when compared with the parent PS.
The optical properties of C60 chemically modified polystyrene (C60-PS copolymer) and the parent polystyrene (PS) films have been investigated.Addition of bulky C60 moiety,a special functional group,to the polystyrene by a novel organometallic reaction modified considerably the optical property of the parent polystyrene.The lattice periodicity of pure PS film is subject to some perturbation or distortion in varying degrees due to the covalent attachment of bulky C60 moiety to the polymer backbone.C60-PS copolymer possesses a new energy band structure with indirect forbidden band when compared with the parent PS.
1997, 8(5): 451-452
Abstract:
A new all aromatic thermotropic liquid crystalline polyester from acetylhydroquinone was prepared by nucleophilic substitution reaction and characterized for its thermotropic liquid crystalline property.The new polyester was amorphous which had glass transition at 274℃.Above Tg.the sample exhibited typical nematic texture.It showed high thermal stability (Td=487℃).
A new all aromatic thermotropic liquid crystalline polyester from acetylhydroquinone was prepared by nucleophilic substitution reaction and characterized for its thermotropic liquid crystalline property.The new polyester was amorphous which had glass transition at 274℃.Above Tg.the sample exhibited typical nematic texture.It showed high thermal stability (Td=487℃).
1997, 8(5): 453-454
Abstract:
Infrared spectra of alternating LB films of octadecyl-TCNQ/CuPc are studied.Charge-transfer complexes are formed in LB films and conductance increases about three orders than that of pure CuPc LB films.
Infrared spectra of alternating LB films of octadecyl-TCNQ/CuPc are studied.Charge-transfer complexes are formed in LB films and conductance increases about three orders than that of pure CuPc LB films.
1997, 8(5): 455-458
Abstract:
The paper reports the synthetic procedure and character of Copper(Ⅱ) binuclear coordination compound of 1,4-bis-(1'-phenyl-3'-methyl-5'-pyrazolone-4')-1,4-butanedione(Cu2L'2). The non-isothermal kinetics of thermal decomposition of the complex has been studied from the TG-DTG curves by means of the Achar et al.and Coats-Redfern methods,the most probable kinetic equation can be expressed as dα/dt=Ae-E/RT *1/(2α).The corresponding kinetic compensation effect expressions are found to be lnA=0.1794E+0.1689.The non-isothermal thermal decomposition process of the complex is one-dimensional diffusion.But electrochemical studies of the complex(Cu2L'2)from cyclic voltammetric curves by means of powder microelectrodes technique(1),shows one two-electron irreversible process.
The paper reports the synthetic procedure and character of Copper(Ⅱ) binuclear coordination compound of 1,4-bis-(1'-phenyl-3'-methyl-5'-pyrazolone-4')-1,4-butanedione(Cu2L'2). The non-isothermal kinetics of thermal decomposition of the complex has been studied from the TG-DTG curves by means of the Achar et al.and Coats-Redfern methods,the most probable kinetic equation can be expressed as dα/dt=Ae-E/RT *1/(2α).The corresponding kinetic compensation effect expressions are found to be lnA=0.1794E+0.1689.The non-isothermal thermal decomposition process of the complex is one-dimensional diffusion.But electrochemical studies of the complex(Cu2L'2)from cyclic voltammetric curves by means of powder microelectrodes technique(1),shows one two-electron irreversible process.
Synthesis,Crystal Structure and Electrochemical Properties of 2-Chlorobenzaldehyde Thiosemicarbazone
1997, 8(5): 459-460
Abstract:
The title compound crystallized in space group P21/c with Z=4,in a unit cell of dimensions,a=12.964(4),b=5.131(5),c=14.970(1)Å;V=9331(1)Å3,Dc=1.429gcm-3,μ=0.541mm-1,R=0.045,Rw=0.059.The equilibrium constant of the ligand with CdBr2 was obtained by polarographic method.Crystal structure determination revealed that the molecule is in transconformation and non-hydrogen atoms of the molecule are in one plane except N(3) atom.
The title compound crystallized in space group P21/c with Z=4,in a unit cell of dimensions,a=12.964(4),b=5.131(5),c=14.970(1)Å;V=9331(1)Å3,Dc=1.429gcm-3,μ=0.541mm-1,R=0.045,Rw=0.059.The equilibrium constant of the ligand with CdBr2 was obtained by polarographic method.Crystal structure determination revealed that the molecule is in transconformation and non-hydrogen atoms of the molecule are in one plane except N(3) atom.
1997, 8(5): 461-464
Abstract:
Reaction of dimers of (R) thionophosphine sulfide (R=P-C6H4OMe,SMe) with Co2(CO)8 yields the novel hexacobalt cluster[Co6(μ3-S)2(CO)14(μ4-η2-SP???OMe)] 1 and the trinuclear cluster[Co3(μ3-S)(CO)7(μ3-PSCH3)] 2.In 1,two Co3S(Co)7 units linked by a novel phosphido-thiolato bifunctional bridging μ4-SPR ligand as backbone.
Reaction of dimers of (R) thionophosphine sulfide (R=P-C6H4OMe,SMe) with Co2(CO)8 yields the novel hexacobalt cluster[Co6(μ3-S)2(CO)14(μ4-η2-SP???OMe)] 1 and the trinuclear cluster[Co3(μ3-S)(CO)7(μ3-PSCH3)] 2.In 1,two Co3S(Co)7 units linked by a novel phosphido-thiolato bifunctional bridging μ4-SPR ligand as backbone.
