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2001 Volume 12 Issue 12
2001, 12(12): 1051-1052
Abstract:
A new chitosan-supported borohydride reducing reagent (CBER) was prepared by treatment of KBH4 with the resin of chitosan derivative, which was first synthesized from the reaction of cross-linked chitosan microsphere with glycidyl trimethylammonium chloride. CBER could reduce aromatic carbonyl compound to corresponding alcohol.
A new chitosan-supported borohydride reducing reagent (CBER) was prepared by treatment of KBH4 with the resin of chitosan derivative, which was first synthesized from the reaction of cross-linked chitosan microsphere with glycidyl trimethylammonium chloride. CBER could reduce aromatic carbonyl compound to corresponding alcohol.
2001, 12(12): 1053-1054
Abstract:
1, 3 Dipolar cycloaddition reaction between vinyl acetate and 3-hydroxypyridiniun betaine was performed under solid-liquid phase transfer catalytic condition. This reaction has been successfully used on the synthesis of an analogue of Bao-Gong-Teng A.
1, 3 Dipolar cycloaddition reaction between vinyl acetate and 3-hydroxypyridiniun betaine was performed under solid-liquid phase transfer catalytic condition. This reaction has been successfully used on the synthesis of an analogue of Bao-Gong-Teng A.
2001, 12(12): 1055-1056
Abstract:
New chiral γ-amino alcohols 1-4 were synthesized and applied in the asymmetric addition of diethylzinc to aldehydes to give sec-alcohol with up to 94.0% enantiomeric excess.
New chiral γ-amino alcohols 1-4 were synthesized and applied in the asymmetric addition of diethylzinc to aldehydes to give sec-alcohol with up to 94.0% enantiomeric excess.
2001, 12(12): 1057-1060
Abstract:
Podophyllotoxin 1 reacts with DDQ in acetic acid to give podophyllotoxone 2 at 75℃ and the naphthol 3 at 90℃, and in TFA to give the naphthalene 4. 4'-O-Benzyl-epipodophyllotoxin 5 reacts with DDQ in acetic acid at 70℃ to give the acetate 8. The structural elucidation of these products is described.
Podophyllotoxin 1 reacts with DDQ in acetic acid to give podophyllotoxone 2 at 75℃ and the naphthol 3 at 90℃, and in TFA to give the naphthalene 4. 4'-O-Benzyl-epipodophyllotoxin 5 reacts with DDQ in acetic acid at 70℃ to give the acetate 8. The structural elucidation of these products is described.
2001, 12(12): 1061-1064
Abstract:
N-Boc-2, 5-bis(trimethylsilyl)pyrrolidine 4 was synthesized from the reaction of N-Boc-pyrrolidine 1 with trimethylsilyl chloride (TMSCl) at optional temperature in one-pot in good yield.
N-Boc-2, 5-bis(trimethylsilyl)pyrrolidine 4 was synthesized from the reaction of N-Boc-pyrrolidine 1 with trimethylsilyl chloride (TMSCl) at optional temperature in one-pot in good yield.
2001, 12(12): 1065-1068
Abstract:
New reactions of Lawesson reagent (LR) with a-hydroxy (amino)nitriles have been studied. The experimental results showed that the five-membered phosphoroheterocycles 2 and 4 bearing N-P-N or S-P-N moiety could be readily prepared in high yields. Meanwhile, the possible mechanism of the reactions was also discussed.
New reactions of Lawesson reagent (LR) with a-hydroxy (amino)nitriles have been studied. The experimental results showed that the five-membered phosphoroheterocycles 2 and 4 bearing N-P-N or S-P-N moiety could be readily prepared in high yields. Meanwhile, the possible mechanism of the reactions was also discussed.
2001, 12(12): 1069-1070
Abstract:
The diarylheptanoids 1-(3',4'-dihydroxyphenyl)-7-(4"-hydroxyphenyl)-4-hepten-3-one 1 and 1-(3',4'-dihydroxyphenyl)-7-(4"-hydroxyphenyl)-5-hydroxy-3-heptanone 2 were synthesized from piperonal 3 and 4-hydroxybenzaldehyde 11.
The diarylheptanoids 1-(3',4'-dihydroxyphenyl)-7-(4"-hydroxyphenyl)-4-hepten-3-one 1 and 1-(3',4'-dihydroxyphenyl)-7-(4"-hydroxyphenyl)-5-hydroxy-3-heptanone 2 were synthesized from piperonal 3 and 4-hydroxybenzaldehyde 11.
2001, 12(12): 1071-1074
Abstract:
The novel 2-propyl-5-phenyl-1, 4-dioxo-1,2,3,4,5,6,7,8-octahydro-[1,4,2] diaza phosphorino[1,2-a] [1,3,2]benzodiazaphosphorine 3-oxide has been synthesized by incorporating the proximate carbonyl and phosphoryl groups into the benzoannulated phosphdiamide heterocycle in good yield.
The novel 2-propyl-5-phenyl-1, 4-dioxo-1,2,3,4,5,6,7,8-octahydro-[1,4,2] diaza phosphorino[1,2-a] [1,3,2]benzodiazaphosphorine 3-oxide has been synthesized by incorporating the proximate carbonyl and phosphoryl groups into the benzoannulated phosphdiamide heterocycle in good yield.
2001, 12(12): 1075-1078
Abstract:
In this paper, we report the synthesis of a potential anti-cancer agent:Cyclo[Val-Lys(DMQ-MA)-Gaba]. The cytotoxic agent conjugated to the N-terminal and the ξ-amino group of lysine of the tripeptide is 2,6-dimethoxyhydroquinone-3-mercaptoacetic acid (DMQ-MA). By employing the rhodamine B degradation method and ESR spectra, we testify the reactive oxygen species——hydroxyl radicals produced by the drug.
In this paper, we report the synthesis of a potential anti-cancer agent:Cyclo[Val-Lys(DMQ-MA)-Gaba]. The cytotoxic agent conjugated to the N-terminal and the ξ-amino group of lysine of the tripeptide is 2,6-dimethoxyhydroquinone-3-mercaptoacetic acid (DMQ-MA). By employing the rhodamine B degradation method and ESR spectra, we testify the reactive oxygen species——hydroxyl radicals produced by the drug.
2001, 12(12): 1079-1080
Abstract:
Reduction of prochiral ferrocenyl ketones 2a-e in the presence of 10 mol% of chiral β-amino alcohols 4a-b provides 1-ferrocenyl alcohols 1a-e in high yields (>85%) with high optically purity (e.e. up to 96%).
Reduction of prochiral ferrocenyl ketones 2a-e in the presence of 10 mol% of chiral β-amino alcohols 4a-b provides 1-ferrocenyl alcohols 1a-e in high yields (>85%) with high optically purity (e.e. up to 96%).
2001, 12(12): 1081-1084
Abstract:
A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiff's base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-soluble cationic chitosan quaternary ammonium salt. The products were characterized by IR, 1HNMR and elemental analysis. The degree of substitution of chitosan quaternary ammonium salt was calculated by elemental analysis.
A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiff's base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-soluble cationic chitosan quaternary ammonium salt. The products were characterized by IR, 1HNMR and elemental analysis. The degree of substitution of chitosan quaternary ammonium salt was calculated by elemental analysis.
2001, 12(12): 1085-1088
Abstract:
The synthesis, characterization, and biological activities of a series of metal porphyrins were described. The complexes 3a~3e were prepared from the reaction of compound 2 with M(OAc)2 in CHCl3, and the treatment of 3a~3f with pyridine gave corresponding complexes 4a~4f. These new compounds were identified by absorption spectroscopies, 1H NMR and elemental analysis. The results of biological activity testing revealed that 4a and 4c had stronger inhibiting action for Escherichia coli (CCTCC AB91115).
The synthesis, characterization, and biological activities of a series of metal porphyrins were described. The complexes 3a~3e were prepared from the reaction of compound 2 with M(OAc)2 in CHCl3, and the treatment of 3a~3f with pyridine gave corresponding complexes 4a~4f. These new compounds were identified by absorption spectroscopies, 1H NMR and elemental analysis. The results of biological activity testing revealed that 4a and 4c had stronger inhibiting action for Escherichia coli (CCTCC AB91115).
2001, 12(12): 1089-1092
Abstract:
Anticancer drug Mitomycin C (MMC) quenches remarkably phosphorescence and reduces lifetime of phosphorescence probe, Pd-meso-tetrakis-(4-trimethylaminophenyl) porphin (Pd-TAPP), in the presence of calf thymus DNA. These results may be attributed to the site competition of MMC with the probe and electron transfer between MMC and probe. MMC also increases polarization degree of the probe by covalent drug-DNA or DNA-drug-DNA crosslinking.
Anticancer drug Mitomycin C (MMC) quenches remarkably phosphorescence and reduces lifetime of phosphorescence probe, Pd-meso-tetrakis-(4-trimethylaminophenyl) porphin (Pd-TAPP), in the presence of calf thymus DNA. These results may be attributed to the site competition of MMC with the probe and electron transfer between MMC and probe. MMC also increases polarization degree of the probe by covalent drug-DNA or DNA-drug-DNA crosslinking.
2001, 12(12): 1093-1096
Abstract:
The bio-mimic reactions of N-phosphoryl amino acids are very important in the study of many biochemical processes. The difference of reactivity between α-COOH and β-COOH in phosphoryl aspartic acid was studied by theoretical study (Hartree-Fock and Density Functional methods) in this paper. The intermediates II containing five-membered ring were more stable than III with six-membered ring. While for intermediates III, the isomers with six-membered ring in apical-equatorial spanning arrangement were more stable than those with di-equatorial spanning arrangement. At B3LYP/6-31G** level, it was shown that transition states IV and V involving α-COOH or β-COOH group had energy barriers of ΔE=58.67 kJ·mol-1 and 103.94 kJ·mol-1, respectively. These results were in agreement with the experimental data. So the α-COOH group was involved in form of the intramolecular penta-coordinate phosphoric-carboxylic mixed anhydride intermediates, but not β-COOH group.
The bio-mimic reactions of N-phosphoryl amino acids are very important in the study of many biochemical processes. The difference of reactivity between α-COOH and β-COOH in phosphoryl aspartic acid was studied by theoretical study (Hartree-Fock and Density Functional methods) in this paper. The intermediates II containing five-membered ring were more stable than III with six-membered ring. While for intermediates III, the isomers with six-membered ring in apical-equatorial spanning arrangement were more stable than those with di-equatorial spanning arrangement. At B3LYP/6-31G** level, it was shown that transition states IV and V involving α-COOH or β-COOH group had energy barriers of ΔE=58.67 kJ·mol-1 and 103.94 kJ·mol-1, respectively. These results were in agreement with the experimental data. So the α-COOH group was involved in form of the intramolecular penta-coordinate phosphoric-carboxylic mixed anhydride intermediates, but not β-COOH group.
2001, 12(12): 1097-1100
Abstract:
By using 1-methyl-2-formyl-5-substituted pyrroles (1-Y), 1-methyl-2-formyl-5-substituted pyrrole phenylhydrazones (2-Y) and 1-methyl-2-formyl-5-substituted pyrrole (4-nitro-phenyl)-hydrazones (3-Y) as model structures for nitrogen-containing heterocyclic aromatic compounds, correlation analysis of their redox potential data show that the transition states (TS) of the polarographic process are mainly affected by the polar effects, but spin-delocalizatin effects also exist.
By using 1-methyl-2-formyl-5-substituted pyrroles (1-Y), 1-methyl-2-formyl-5-substituted pyrrole phenylhydrazones (2-Y) and 1-methyl-2-formyl-5-substituted pyrrole (4-nitro-phenyl)-hydrazones (3-Y) as model structures for nitrogen-containing heterocyclic aromatic compounds, correlation analysis of their redox potential data show that the transition states (TS) of the polarographic process are mainly affected by the polar effects, but spin-delocalizatin effects also exist.
2001, 12(12): 1101-1104
Abstract:
In this work, the self-assembled monolayer of Schiff base was first investigated using electrochemical impedance spectroscopy (EIS). The complexation of Cu2+ with the Schiff base was also detected with EIS method. The approximate linear relationship between Cu2+ and the reaction resistance (Rr) was observed. All the results suggest that the electrochemical property of Schiff base could be studied conveniently by means of forming self-assembled monolayer.
In this work, the self-assembled monolayer of Schiff base was first investigated using electrochemical impedance spectroscopy (EIS). The complexation of Cu2+ with the Schiff base was also detected with EIS method. The approximate linear relationship between Cu2+ and the reaction resistance (Rr) was observed. All the results suggest that the electrochemical property of Schiff base could be studied conveniently by means of forming self-assembled monolayer.
2001, 12(12): 1105-1108
Abstract:
This paper reports the molecular assembly in the LB film of a novel bolaamphiphilic anthracene derivative (BISANS) in comparison with that of one-headed amphiphilic anthracene derivative (ANS). While ANS formed a stretched monolayer at the air/water interface, BISANS underwent aggregation to form crystal film on the water surface. Both of the H-aggregates and J-aggregates exist in the transferred LB films of bolaamphiphilic BISANS, only J-aggregates formed in the LB film of ANS.
This paper reports the molecular assembly in the LB film of a novel bolaamphiphilic anthracene derivative (BISANS) in comparison with that of one-headed amphiphilic anthracene derivative (ANS). While ANS formed a stretched monolayer at the air/water interface, BISANS underwent aggregation to form crystal film on the water surface. Both of the H-aggregates and J-aggregates exist in the transferred LB films of bolaamphiphilic BISANS, only J-aggregates formed in the LB film of ANS.
2001, 12(12): 1109-1112
Abstract:
The steady-state fluorescence method has been tentatively used to determine the phase structures of microemulsion systems consisting of cetyltrimethylammonium bromide (CTAB), n-butanol (n-C4H9OH), octane (n-C8H18), and water. The excimer/monomer intensity ratio (Ie/Im) of pyrene has demonstrated that the various structures in the microemulsion phase region can be distinguished. The results are consistent with electrical conductivity data already reported.
The steady-state fluorescence method has been tentatively used to determine the phase structures of microemulsion systems consisting of cetyltrimethylammonium bromide (CTAB), n-butanol (n-C4H9OH), octane (n-C8H18), and water. The excimer/monomer intensity ratio (Ie/Im) of pyrene has demonstrated that the various structures in the microemulsion phase region can be distinguished. The results are consistent with electrical conductivity data already reported.
2001, 12(12): 1113-1114
Abstract:
The probe effect on the apparent image of biological atomic force microscopy was explored in this study, and the potential of AFM in conformational study of gene related biological processes was illustrated by the specific nanostructural information of a new antitumor drug binding to DNA.
The probe effect on the apparent image of biological atomic force microscopy was explored in this study, and the potential of AFM in conformational study of gene related biological processes was illustrated by the specific nanostructural information of a new antitumor drug binding to DNA.
2001, 12(12): 1115-1118
Abstract:
The catalytic properties of a series of (dppe) MCl2[M=Fe(II), Co(II), Ni(II)] in combination with EAO (ethylaluminoxane) for ethylene oligomerization have been investigated. Treatment of the bidentate phosphine metal complexes with EAO in toluene generated in situ active catalysts which catalyze oligomerizaton of ethylene to low-carbon olefins. The effects of reaction temperature, ratios of n(Al):n(M) and reaction periods on catalytic activity and product distribution have been studied. The activity of cobalt complex with EAO at 200℃ was 4021 g/g(Co)·h, and the selectivity of C4-10 olefins is 95.5%.
The catalytic properties of a series of (dppe) MCl2[M=Fe(II), Co(II), Ni(II)] in combination with EAO (ethylaluminoxane) for ethylene oligomerization have been investigated. Treatment of the bidentate phosphine metal complexes with EAO in toluene generated in situ active catalysts which catalyze oligomerizaton of ethylene to low-carbon olefins. The effects of reaction temperature, ratios of n(Al):n(M) and reaction periods on catalytic activity and product distribution have been studied. The activity of cobalt complex with EAO at 200℃ was 4021 g/g(Co)·h, and the selectivity of C4-10 olefins is 95.5%.
2001, 12(12): 1119-1122
Abstract:
Supported Cu catalysts for low-temperature CO oxidation were prepared by solvated metal atom impregnation (SMAI). X-ray photoelectron spectroscopy (XPS) investigations indicated that the copper in all the samples was in a metallic state. XRD measurements showed that the mean diameters of Cu particles prepared by SMAI were small. Catalytical tests showed that the SMAI catalyst had high CO oxidation activity.
Supported Cu catalysts for low-temperature CO oxidation were prepared by solvated metal atom impregnation (SMAI). X-ray photoelectron spectroscopy (XPS) investigations indicated that the copper in all the samples was in a metallic state. XRD measurements showed that the mean diameters of Cu particles prepared by SMAI were small. Catalytical tests showed that the SMAI catalyst had high CO oxidation activity.
2001, 12(12): 1123-1126
Abstract:
A supported Ni-B/TiO2 amorphous catalyst was prepared by impregnation and reduction. It was characterized by XRD, SAED, DSC, XPS, etc.. The catalytic activity of catalyst was measured through the hydrogenation of heavy arenes in petrochemicals for the first time.
A supported Ni-B/TiO2 amorphous catalyst was prepared by impregnation and reduction. It was characterized by XRD, SAED, DSC, XPS, etc.. The catalytic activity of catalyst was measured through the hydrogenation of heavy arenes in petrochemicals for the first time.
2001, 12(12): 1127-1130
Abstract:
Two new ultrathin multiplayer films have been successfully prepared from Keggin-type heteropoly acids H4[SiW12O40] and H3[PMo12040] with polyelectrolytes PEI, PSS, and PAH, using the electrostatic layer-by-layer self-assembly technique. The XR results reveal their film thickness at nanoscale (~20 nm). According to the AFM images, it is believed that the surface roughness (rough degree of film surface) of the polyelectrolyte-polyoxometalate film greatly depends on the kind of polyoxometalates.
Two new ultrathin multiplayer films have been successfully prepared from Keggin-type heteropoly acids H4[SiW12O40] and H3[PMo12040] with polyelectrolytes PEI, PSS, and PAH, using the electrostatic layer-by-layer self-assembly technique. The XR results reveal their film thickness at nanoscale (~20 nm). According to the AFM images, it is believed that the surface roughness (rough degree of film surface) of the polyelectrolyte-polyoxometalate film greatly depends on the kind of polyoxometalates.
2001, 12(12): 1131-1134
Abstract:
A new conformational carbon-carbon bond free radical initiator diethyl [2,3-di(ethoxycarbonyl)-2,3-di(p-nitrophenyl)] succinate (EMNPS) was synthesized and identified by elemental analysis, FAB-MS, IR and 1H NMR spectroscopy. The analytical results of single crystal X-ray show the conforma-tion of EMNPS tends to be a stagger gauche form, and torsion angle of the two gauche phenyls is smaller than 60°. There is obvious elongation in central carbon-carbon bond length (0.161 nm). EMNPS can be decomposed into two relatively stable free radicals measured by ESR. By initiating bulk polymeriza-tion of methyl methacrylate (MMA), EMNPS shows the ability of controlling the molecular weight of polymers.
A new conformational carbon-carbon bond free radical initiator diethyl [2,3-di(ethoxycarbonyl)-2,3-di(p-nitrophenyl)] succinate (EMNPS) was synthesized and identified by elemental analysis, FAB-MS, IR and 1H NMR spectroscopy. The analytical results of single crystal X-ray show the conforma-tion of EMNPS tends to be a stagger gauche form, and torsion angle of the two gauche phenyls is smaller than 60°. There is obvious elongation in central carbon-carbon bond length (0.161 nm). EMNPS can be decomposed into two relatively stable free radicals measured by ESR. By initiating bulk polymeriza-tion of methyl methacrylate (MMA), EMNPS shows the ability of controlling the molecular weight of polymers.
2001, 12(12): 1135-1138
Abstract:
High-quality carbon nanotubes were continuously produced by using moving bed reactor. The studies of scanning electron microscopy and transmission electron microscopy reveal their homogeneity both in inner (~10 nm) and outer diameter (20-40 nm) of the tubes. The studies of X-ray photoelectron spectroscopy and the oxidation of carbon nanotubes in air demonstrate that the tubes have good graphitic degree.
High-quality carbon nanotubes were continuously produced by using moving bed reactor. The studies of scanning electron microscopy and transmission electron microscopy reveal their homogeneity both in inner (~10 nm) and outer diameter (20-40 nm) of the tubes. The studies of X-ray photoelectron spectroscopy and the oxidation of carbon nanotubes in air demonstrate that the tubes have good graphitic degree.
2001, 12(12): 1139-1140
Abstract:
Novel silicon nanotubes with inner-diameter of 60-80 nm was prepared using hydrogen-added dechlorination of SiCl4 followed by chemical vapor deposition (CVD) on a NixMgyO catalyst. The TEM observation showed that the suitable reaction temperature is 973 K for the formation of silicon nanotubes. Most of silicon nanotubes have one open end and some have two closed ends. The shape of nanoscale silicon, however, is a micro-crystal type at 873 K, a rod or needle type at 993 K and an onion-type at 1023 K, respectively.
Novel silicon nanotubes with inner-diameter of 60-80 nm was prepared using hydrogen-added dechlorination of SiCl4 followed by chemical vapor deposition (CVD) on a NixMgyO catalyst. The TEM observation showed that the suitable reaction temperature is 973 K for the formation of silicon nanotubes. Most of silicon nanotubes have one open end and some have two closed ends. The shape of nanoscale silicon, however, is a micro-crystal type at 873 K, a rod or needle type at 993 K and an onion-type at 1023 K, respectively.
2001, 12(12): 1141-1144
Abstract:
Through the reduction of [AuCl4]- by aqueous sodium borohydride in the presence of 9-(5-thiopentyl)-carbazole, the gold nanoparticles has been prepared and characterized.
Through the reduction of [AuCl4]- by aqueous sodium borohydride in the presence of 9-(5-thiopentyl)-carbazole, the gold nanoparticles has been prepared and characterized.
