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2015 Volume 36 Issue 4
2015, 36(4): 700-710
doi: 10.6023/cjoc201511008
Abstract:
As a kind of important three-carbon building block, vinamidinium salts have been widely used in organic synthesis. In this paper the synthetic methods of vinamidinium salts are summarized, and its applications in the synthesis of aldehydes, aromatic and heterocyclic compounds in recent years are reviewed.
As a kind of important three-carbon building block, vinamidinium salts have been widely used in organic synthesis. In this paper the synthetic methods of vinamidinium salts are summarized, and its applications in the synthesis of aldehydes, aromatic and heterocyclic compounds in recent years are reviewed.
2015, 36(4): 711-723
doi: 10.6023/cjoc201510002
Abstract:
Benzo[b][1, 4]diazepine derivatives is a class of benzo and seven-number heterocyclic compounds containing double nitrogen atoms. It was concerned for its special structural features, strong physiological and pharmacological activity. Therefore, the research on synthetic method and biological activity of benzo[b][1, 4]diazepine has become one of the hot issues in the chemical and pharmaceutical areas. Their application in the antimicrobial, anti-neuroinflammatory, anticancer activity and so on in the recently ten years is reviewed. Besides, the progress in synthesis of the benzo[b][1, 4]diazepine compounds at different types of catalysts and its synthetic reaction mechanisms are summarized. Meanwhile, the recent works of authors' research group are discussed. Their synthesis and application prospects are also expected.
Benzo[b][1, 4]diazepine derivatives is a class of benzo and seven-number heterocyclic compounds containing double nitrogen atoms. It was concerned for its special structural features, strong physiological and pharmacological activity. Therefore, the research on synthetic method and biological activity of benzo[b][1, 4]diazepine has become one of the hot issues in the chemical and pharmaceutical areas. Their application in the antimicrobial, anti-neuroinflammatory, anticancer activity and so on in the recently ten years is reviewed. Besides, the progress in synthesis of the benzo[b][1, 4]diazepine compounds at different types of catalysts and its synthetic reaction mechanisms are summarized. Meanwhile, the recent works of authors' research group are discussed. Their synthesis and application prospects are also expected.
2015, 36(4): 724-735
doi: 10.6023/cjoc201510022
Abstract:
Ocotillol-type saponins are a kind of tetracyclic triterpenoid ginsenoside with a tetrahydrofuran ring in the side chain. Ocotillol-type saponins mainly exist in panax plants and possess anti-inflammatory, antibacterial, morphine-antagonis-tic, neuroprotective, cardioprotective effects, etc. There are less ocotillol-type saponins in natural plants. Recently, many studies on the semi-synthesis, absolute configuration confirmation using X-ray diffraction, effect of anti-myocardial ischemic and metabolism of 20(S)-ocotillol-type saponins have been reported. It was found that 24R-epimer and 24S-epimer had stereoselectivity in anti-ischemic effect and pharmacokinetics. In this paper, the advances of the separation, synthesis, absolute configuration confirmation, pharmacological activity, metabolism of ocotillol-type saponins are reviewed.
Ocotillol-type saponins are a kind of tetracyclic triterpenoid ginsenoside with a tetrahydrofuran ring in the side chain. Ocotillol-type saponins mainly exist in panax plants and possess anti-inflammatory, antibacterial, morphine-antagonis-tic, neuroprotective, cardioprotective effects, etc. There are less ocotillol-type saponins in natural plants. Recently, many studies on the semi-synthesis, absolute configuration confirmation using X-ray diffraction, effect of anti-myocardial ischemic and metabolism of 20(S)-ocotillol-type saponins have been reported. It was found that 24R-epimer and 24S-epimer had stereoselectivity in anti-ischemic effect and pharmacokinetics. In this paper, the advances of the separation, synthesis, absolute configuration confirmation, pharmacological activity, metabolism of ocotillol-type saponins are reviewed.
2015, 36(4): 736-743
doi: 10.6023/cjoc201511011
Abstract:
Currently, the majority of the chemotherapy for type 2 diabetes mellitus (T2DM) functions through glycemic control by administration of oral or injectable hypoglycemic drugs. Though a range of anti-diabetic drugs with different modes of action have been launched, there still remains a significant need for development of effective and highly safe anti-diabetic agents for the increasing diabetic population. GPR40 belongs to the GPCR family and the activation of GPR40 can amplify glucose-stimulated insulin secretion (GSIS). Due to the advantage of minimizing the hypoglycemia risk, GPR40 has drawn more and more attention and emerged as a promising new target for T2DM treatment. Therefore, the recent progress on the structural optimization and further development of small molecule GPR40 agonists as novel treatment for T2DM is reviewed, focused on those under clinical trials or at preclinical stage. A variety of small molecule GPR40 agonists were summarized from the literature and patents based on the pharmacophore model, including the critical phenylpropanoic acid core, the hydrophobic terminus and the linker. The structural features and advantage of different sources of GPR40 agonists were analyzed and highlighted.
Currently, the majority of the chemotherapy for type 2 diabetes mellitus (T2DM) functions through glycemic control by administration of oral or injectable hypoglycemic drugs. Though a range of anti-diabetic drugs with different modes of action have been launched, there still remains a significant need for development of effective and highly safe anti-diabetic agents for the increasing diabetic population. GPR40 belongs to the GPCR family and the activation of GPR40 can amplify glucose-stimulated insulin secretion (GSIS). Due to the advantage of minimizing the hypoglycemia risk, GPR40 has drawn more and more attention and emerged as a promising new target for T2DM treatment. Therefore, the recent progress on the structural optimization and further development of small molecule GPR40 agonists as novel treatment for T2DM is reviewed, focused on those under clinical trials or at preclinical stage. A variety of small molecule GPR40 agonists were summarized from the literature and patents based on the pharmacophore model, including the critical phenylpropanoic acid core, the hydrophobic terminus and the linker. The structural features and advantage of different sources of GPR40 agonists were analyzed and highlighted.
2015, 36(4): 774-781
doi: 10.6023/cjoc201510028
Abstract:
A novel fluorescent dye naphthalene imide-fluorine boron two pyrrole 1-(2-(4-(1, 3, 5, 7-tetramethyl fluorine boron pyrrole)phenoxy)ethyl)-4-(4-N-butyl-1, 8-naphthalene imide)-1, 2, 3-triazole (NP-BODIPY) has been synthesized by Click reaction and characterized by 1H NMR, 13C NMR and HRMS techniques. NP-BODIPY has the property of intermolecule fluorescence resonance energy transfer from the naphthalene imide to BODIPY, the NP-BODIPY/SiO2nanoparticles was prepared by positive phase microemulsion. In the test of the UV-vis absorption and fluorescence spectrum of NP-BODIP, purple fluorescence could be observed under ultraviolet lamp when NP-BODIPY was in solid state, green fluorescence could be observed when NP-BODIPY was in THF solution, fluorescence spectrum exhibited bimodal structure in 430 and 510 nm, the fluorescence quantum efficiency of NP-BODIPY was 67% and the ultraviolet absorption peaks were at 366 and 500 nm. The fluorescence quantum efficiency of NP-BODIPY in H2O/THF mixture solution is 39%. It has strong fluorescence when water fraction is 80%, and the maximum fluorescence peaks are at 510 nm. When NP-BODIPY was co-incubated with michigan cancer foundation-7 cells (MCF-7) cells, the fluorescent dye penetrated into the MCF-7 cells and could be clearly observed. NP-BODIPY/SiO2 nanoparticles exhibit good water solubility, size controllable, low cytotoxicity and good biocompatibility. So NP-BODIPY can be widely used for biomarkers and fluorescence imaging.
A novel fluorescent dye naphthalene imide-fluorine boron two pyrrole 1-(2-(4-(1, 3, 5, 7-tetramethyl fluorine boron pyrrole)phenoxy)ethyl)-4-(4-N-butyl-1, 8-naphthalene imide)-1, 2, 3-triazole (NP-BODIPY) has been synthesized by Click reaction and characterized by 1H NMR, 13C NMR and HRMS techniques. NP-BODIPY has the property of intermolecule fluorescence resonance energy transfer from the naphthalene imide to BODIPY, the NP-BODIPY/SiO2nanoparticles was prepared by positive phase microemulsion. In the test of the UV-vis absorption and fluorescence spectrum of NP-BODIP, purple fluorescence could be observed under ultraviolet lamp when NP-BODIPY was in solid state, green fluorescence could be observed when NP-BODIPY was in THF solution, fluorescence spectrum exhibited bimodal structure in 430 and 510 nm, the fluorescence quantum efficiency of NP-BODIPY was 67% and the ultraviolet absorption peaks were at 366 and 500 nm. The fluorescence quantum efficiency of NP-BODIPY in H2O/THF mixture solution is 39%. It has strong fluorescence when water fraction is 80%, and the maximum fluorescence peaks are at 510 nm. When NP-BODIPY was co-incubated with michigan cancer foundation-7 cells (MCF-7) cells, the fluorescent dye penetrated into the MCF-7 cells and could be clearly observed. NP-BODIPY/SiO2 nanoparticles exhibit good water solubility, size controllable, low cytotoxicity and good biocompatibility. So NP-BODIPY can be widely used for biomarkers and fluorescence imaging.
2015, 36(4): 782-786
doi: 10.6023/cjoc201511009
Abstract:
Three chiral fluorescence chemosensors L-1, D-1 and L-2 based on acridine were synthesized. The structures of these compounds were characterized by IR, NMR and MS. The chiral recognition property of such sensors was studied by UV-vis and fluorescence titration. The results demonstrate that the sensors L-1 and D-1 exhibit a good enantioselectivity recognition ability toward tartrate and formed 1:1 complex.
Three chiral fluorescence chemosensors L-1, D-1 and L-2 based on acridine were synthesized. The structures of these compounds were characterized by IR, NMR and MS. The chiral recognition property of such sensors was studied by UV-vis and fluorescence titration. The results demonstrate that the sensors L-1 and D-1 exhibit a good enantioselectivity recognition ability toward tartrate and formed 1:1 complex.
2015, 36(4): 787-794
doi: 10.6023/cjoc201511016
Abstract:
Zinc ion (Zn2+) is one of the most important transition-metal ions in the human body which is involved in many important life activities and many diseases can be displayed by its situation. Thus, monitoring of Zn2+ is very meaningful to diagnosis of diseases. Compared to the traditional detection methods, fluorescence probe is safer and more practical. Because coumarin derivatives possess several advantages in optics, we choose them as key structures to prepare new fluorescent probes. Based on the mechaism of photoinduced electron transfer (PET), the water-soluble fluorescent probes 1 and 2that are coumarin-based derivatives were designed, which demonstrated sensitivity for Zn2+ and exhibited high selectivity to Zn2+ over other metal ions. The receptor unit serves as an electron donor in the absence of Zn2+, quenching the fluorophore excited state that makes the probe have no fluorescence. However, when Zn2+ binds to the receptor, photoinduced electron transfer is prevented and the quenching is blocked, resulting the fluorescence intensity significantly enhanced. There is a good correlation between fluorescence intensity and Zn2+ concentration. With the increase of Zn2+ concentration, fluorescence intensity becomes stronger. Furthermore, the two probes were successfully labelled on the MCF-7 cell and B. subtilis. The single crystals of the coumarin-based compounds 1~4 and zinc complex [Zn(2)] were also obtained. The X-ray crystal structure of the zinc complex [Zn(2)] reveals that the hydroxyl group and the 2, 2-dipicolylaminomethyl group participate in coordination. Zn2+ is five-coordinated with three nitrogen atoms from the pyridine rings, the substituted amino group and two oxygen atoms from the 7-site hydroxyl group, also coordinated with water molecule forming a pentacoordinated bipyramid geometry.
Zinc ion (Zn2+) is one of the most important transition-metal ions in the human body which is involved in many important life activities and many diseases can be displayed by its situation. Thus, monitoring of Zn2+ is very meaningful to diagnosis of diseases. Compared to the traditional detection methods, fluorescence probe is safer and more practical. Because coumarin derivatives possess several advantages in optics, we choose them as key structures to prepare new fluorescent probes. Based on the mechaism of photoinduced electron transfer (PET), the water-soluble fluorescent probes 1 and 2that are coumarin-based derivatives were designed, which demonstrated sensitivity for Zn2+ and exhibited high selectivity to Zn2+ over other metal ions. The receptor unit serves as an electron donor in the absence of Zn2+, quenching the fluorophore excited state that makes the probe have no fluorescence. However, when Zn2+ binds to the receptor, photoinduced electron transfer is prevented and the quenching is blocked, resulting the fluorescence intensity significantly enhanced. There is a good correlation between fluorescence intensity and Zn2+ concentration. With the increase of Zn2+ concentration, fluorescence intensity becomes stronger. Furthermore, the two probes were successfully labelled on the MCF-7 cell and B. subtilis. The single crystals of the coumarin-based compounds 1~4 and zinc complex [Zn(2)] were also obtained. The X-ray crystal structure of the zinc complex [Zn(2)] reveals that the hydroxyl group and the 2, 2-dipicolylaminomethyl group participate in coordination. Zn2+ is five-coordinated with three nitrogen atoms from the pyridine rings, the substituted amino group and two oxygen atoms from the 7-site hydroxyl group, also coordinated with water molecule forming a pentacoordinated bipyramid geometry.
2015, 36(4): 795-802
doi: 10.6023/cjoc201509002
Abstract:
Based on the combination principle, twelve novel oleanolic acid and ursolic acid derivatives were designed and synthesized through introduction of piperazine, N-methyl piperazine and morpholine moiety in C-28 position. Structures of all target compounds were characterized by IR, 1H NMR, 13C NMR and HRMS. Their in vitro anticancer activities towards MCF-7, Hela and A549 cell lines were evaluated by a 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl tetrazolium bromide (MTT) method. The results indicate that OA-4, OA-7, OA-8a, OA-8b, UA-4, UA-7, UA-8a and UA-8b against MCF-7, Hela and A549 cells are obviously better than OA and UA, OA-4, OA-7, UA-4 and UA-7 are equally as well the IC50 of positive control gefitinib.
Based on the combination principle, twelve novel oleanolic acid and ursolic acid derivatives were designed and synthesized through introduction of piperazine, N-methyl piperazine and morpholine moiety in C-28 position. Structures of all target compounds were characterized by IR, 1H NMR, 13C NMR and HRMS. Their in vitro anticancer activities towards MCF-7, Hela and A549 cell lines were evaluated by a 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl tetrazolium bromide (MTT) method. The results indicate that OA-4, OA-7, OA-8a, OA-8b, UA-4, UA-7, UA-8a and UA-8b against MCF-7, Hela and A549 cells are obviously better than OA and UA, OA-4, OA-7, UA-4 and UA-7 are equally as well the IC50 of positive control gefitinib.
2015, 36(4): 803-811
doi: 10.6023/cjoc201510008
Abstract:
Based on 10-methyl-10H-phenothiazine-5, 5-dioxide unit as an acceptor and 9, 10-dihydro-9, 9-dimethyl-acridine (DMAC) or phenoxazine (PXZ) as donors, four intramolecular charge transfer (ICT) compounds were designed and synthesized by Buchwald-Hartwig cross coupling reactions. Their ground-state geometries were optimized with density functional theory (DFT) at B3LYP level and vertical transition energies were calculated using the optimal Hartree-Fock (HF) exchange method. Resulting compounds were characterized by fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, liquid chromatography-mass (LC-MS) spectrometry and hybrid quadrupole time-of-flight mass spectrometry (QTOF). Their photophysical properties were systematically investigated. The results show that compound 2a has maximum emission wavelength (λmax) of 422 nm in toluene and its oxygen-free one has photoluminescence quantum yield (PLQY) of 0.367. Theλmax and PLQY for 1a and 1b are 455 nm, 0.083 and 511 nm, 0.098, respectively. Transient photoluminescence decay curves for 5 wt% 1a and 1b doped in PMMA films indicate that their delayed fluorescence lifetimes are 5.78 and 20.00 μs, respectively. According to the time-resolved fluorescence and phosphorescence spectra of 1a and 1b doped in PMMA films at 77 K, their energy gaps (ΔEST) between the lowest singlet state (S1) and the lowest triplet excited state (T1) are determined to be 0.203 and 0.177 eV, respectively, which are consistent with the theoretical values 0.232 and 0.295 eV calculated with time-dependent density functional theory (TD-DFT). As a result, 1a and 1b are expected to be potential thermally activated delayed fluorescence (TADF) materials. The electrochemical properties of the four compounds in dichloromethane solution were determined through cyclic voltammetry using TBAPF6 as supporting electrolyte and ferrocene as internal standard. The HOMO energy levels of 1a, 1b, 2a and 2b are estimated to be -5.369, -5.111, -5.412 and -5.075 eV, respectively. The thermal properties of the four compounds were investigated by thermal gravimetric analysis under nitrogen atmosphere at a heating rate of 10 ℃·min-1 and all compounds show good thermal stability with decomposition temperatures above 420 ℃.
Based on 10-methyl-10H-phenothiazine-5, 5-dioxide unit as an acceptor and 9, 10-dihydro-9, 9-dimethyl-acridine (DMAC) or phenoxazine (PXZ) as donors, four intramolecular charge transfer (ICT) compounds were designed and synthesized by Buchwald-Hartwig cross coupling reactions. Their ground-state geometries were optimized with density functional theory (DFT) at B3LYP level and vertical transition energies were calculated using the optimal Hartree-Fock (HF) exchange method. Resulting compounds were characterized by fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, liquid chromatography-mass (LC-MS) spectrometry and hybrid quadrupole time-of-flight mass spectrometry (QTOF). Their photophysical properties were systematically investigated. The results show that compound 2a has maximum emission wavelength (λmax) of 422 nm in toluene and its oxygen-free one has photoluminescence quantum yield (PLQY) of 0.367. Theλmax and PLQY for 1a and 1b are 455 nm, 0.083 and 511 nm, 0.098, respectively. Transient photoluminescence decay curves for 5 wt% 1a and 1b doped in PMMA films indicate that their delayed fluorescence lifetimes are 5.78 and 20.00 μs, respectively. According to the time-resolved fluorescence and phosphorescence spectra of 1a and 1b doped in PMMA films at 77 K, their energy gaps (ΔEST) between the lowest singlet state (S1) and the lowest triplet excited state (T1) are determined to be 0.203 and 0.177 eV, respectively, which are consistent with the theoretical values 0.232 and 0.295 eV calculated with time-dependent density functional theory (TD-DFT). As a result, 1a and 1b are expected to be potential thermally activated delayed fluorescence (TADF) materials. The electrochemical properties of the four compounds in dichloromethane solution were determined through cyclic voltammetry using TBAPF6 as supporting electrolyte and ferrocene as internal standard. The HOMO energy levels of 1a, 1b, 2a and 2b are estimated to be -5.369, -5.111, -5.412 and -5.075 eV, respectively. The thermal properties of the four compounds were investigated by thermal gravimetric analysis under nitrogen atmosphere at a heating rate of 10 ℃·min-1 and all compounds show good thermal stability with decomposition temperatures above 420 ℃.
2015, 36(4): 812-817
doi: 10.6023/cjoc201510038
Abstract:
A novel binaphthol-based monomer, 3-hydroxydiphenylmethyl-3'-vinyl-2, 2'-dihydroxy-1, 1'-binaphthyl was synthesized and polymerized using azodiisobutyrodinitrile (AIBN) as an initiator to afford the polymer P-5. Polarimetry, UV-Vis and circular dichroism spectroscopy characterizations indicated that the polymer existed in the form of one-handed helical structure in solution. The application of helical polymer P-5 in catalytic asymmetric hetero-Diels-Alder (HDA) reaction between benzaldehyde and Danishefsky's diene has been studied, resulting in the target product with 71% ee. P-5can be easily recovered and reused without loss of catalytic activity.
A novel binaphthol-based monomer, 3-hydroxydiphenylmethyl-3'-vinyl-2, 2'-dihydroxy-1, 1'-binaphthyl was synthesized and polymerized using azodiisobutyrodinitrile (AIBN) as an initiator to afford the polymer P-5. Polarimetry, UV-Vis and circular dichroism spectroscopy characterizations indicated that the polymer existed in the form of one-handed helical structure in solution. The application of helical polymer P-5 in catalytic asymmetric hetero-Diels-Alder (HDA) reaction between benzaldehyde and Danishefsky's diene has been studied, resulting in the target product with 71% ee. P-5can be easily recovered and reused without loss of catalytic activity.
2015, 36(4): 838-843
doi: 10.6023/cjoc201510010
Abstract:
An efficient method for the synthesis of benzopyran derivatives and pyrano[2, 3-c]pyrazole derivatives via multicomponent reaction in the presence of agarose hydrogel entrapped trisodium citrate (gel-citrate) as catalyst is developed. The protocol presented here has the merits of easy preparation and handling of catalyst, environmentally benign, simple operation and convenient workup, and excellent yields. Moreover, the catalyst could be recovered and reused at least 6 cycles without apparently losing its activities.
An efficient method for the synthesis of benzopyran derivatives and pyrano[2, 3-c]pyrazole derivatives via multicomponent reaction in the presence of agarose hydrogel entrapped trisodium citrate (gel-citrate) as catalyst is developed. The protocol presented here has the merits of easy preparation and handling of catalyst, environmentally benign, simple operation and convenient workup, and excellent yields. Moreover, the catalyst could be recovered and reused at least 6 cycles without apparently losing its activities.
2015, 36(4): 844-849
doi: 10.6023/cjoc201511029
Abstract:
A new ether-based benzoxazine monomer having a benzoyl moiety in the side chain is reported. This monomer showed good solubility in common organic solvents and low melting point ( < 125 ℃). Upon heating at high temperature, the monomer converted to an insoluble and infusible resin, which showed high thermostability with a 5 wt% weight loss temperature of 380 ℃ and a char yield of 66% at 800 ℃. Moreover, the resin exhibitedgood addhesion ability to metals with the shear strength of 6.5 MPa. For comparison, a benzoxazine without benzoyl unit was prepared. After cured, such a comparative benzoxazine showed a 5 wt% weight loss temperature of 322 ℃ and a char yield of 43%, and the shear strength of 4.7 MPa, respectively. These results indicate that the introduction of the a benzoyl moiety into the ether-based benzoxazine as the side chain can efficiently improve both of the thermostability and mechanical properties of the benzoxazine. This new benzoxazine could be used as matrix or producing the carbon/glass fiber reinforced composites, as well as the adhesives for binding the metals.
A new ether-based benzoxazine monomer having a benzoyl moiety in the side chain is reported. This monomer showed good solubility in common organic solvents and low melting point ( < 125 ℃). Upon heating at high temperature, the monomer converted to an insoluble and infusible resin, which showed high thermostability with a 5 wt% weight loss temperature of 380 ℃ and a char yield of 66% at 800 ℃. Moreover, the resin exhibitedgood addhesion ability to metals with the shear strength of 6.5 MPa. For comparison, a benzoxazine without benzoyl unit was prepared. After cured, such a comparative benzoxazine showed a 5 wt% weight loss temperature of 322 ℃ and a char yield of 43%, and the shear strength of 4.7 MPa, respectively. These results indicate that the introduction of the a benzoyl moiety into the ether-based benzoxazine as the side chain can efficiently improve both of the thermostability and mechanical properties of the benzoxazine. This new benzoxazine could be used as matrix or producing the carbon/glass fiber reinforced composites, as well as the adhesives for binding the metals.
2015, 36(4): 855-861
doi: 10.6023/cjoc201510030
Abstract:
Dibenzo-24-crown-8 (DB24C8) and dibenzylammonium (DBA) are always utilized for the construction of supramolecular assemblies. We reported a new kind supramolecular assembly polymer constructed by M1 which was synthesized from tetraphenylethene (TPE) linked with DB24C8 and DBA through click reaction. The chemical structures of all the compounds were fully characterized by 1H NMR, 13C NMR, and MS. The 1H NMR titration showed that the supramolecular assembly was successfully constructed in acidic condition. The fluorescent results showed that the assemblies displayed ratio-metric properties with the changes of aggregation-induced emission and monomer-emission, and fluorescence quenching with addition of Pd2+.
Dibenzo-24-crown-8 (DB24C8) and dibenzylammonium (DBA) are always utilized for the construction of supramolecular assemblies. We reported a new kind supramolecular assembly polymer constructed by M1 which was synthesized from tetraphenylethene (TPE) linked with DB24C8 and DBA through click reaction. The chemical structures of all the compounds were fully characterized by 1H NMR, 13C NMR, and MS. The 1H NMR titration showed that the supramolecular assembly was successfully constructed in acidic condition. The fluorescent results showed that the assemblies displayed ratio-metric properties with the changes of aggregation-induced emission and monomer-emission, and fluorescence quenching with addition of Pd2+.
2015, 36(4): 862-866
doi: 10.6023/cjoc201510027
Abstract:
A green and efficient protocol for the synthesis of phenols using recyclable chitosan@copper as catalyst was developed. Phenols can be obtained in moderate to excellent yields. The catalyst can be recycled and reused for five times without significant loss of its catalytic activity.
A green and efficient protocol for the synthesis of phenols using recyclable chitosan@copper as catalyst was developed. Phenols can be obtained in moderate to excellent yields. The catalyst can be recycled and reused for five times without significant loss of its catalytic activity.
2015, 36(4): 867-871
doi: 10.6023/cjoc201511023
Abstract:
We report selective detection of homocysteine (Hcy) through luminescent poly methyl vinyl ether-alt-maleic acid (PMVEM) silver nanoclusters (Ag NCs), which were synthesized using PMVEM as scaffold. The as-developed PMVEM-Ag NCs have two emission peaks at 460 and 540 nm. After Hcy was added, the thiol moiety of Hcy can efficiently coordinate on Ag NCs, resulting in luminescence quenching of the 460 and 540 nm peaks. However, the ratio of these two emission peak was linearly correlated with the Hcy concentration from 5 to 100 μmol/L. The detection limits was 1 μmol/L. The detection of Hcy used the ratio of the two emission peaks, which permit selective detection of Hcy and quantitive determination of Hcy levels.
We report selective detection of homocysteine (Hcy) through luminescent poly methyl vinyl ether-alt-maleic acid (PMVEM) silver nanoclusters (Ag NCs), which were synthesized using PMVEM as scaffold. The as-developed PMVEM-Ag NCs have two emission peaks at 460 and 540 nm. After Hcy was added, the thiol moiety of Hcy can efficiently coordinate on Ag NCs, resulting in luminescence quenching of the 460 and 540 nm peaks. However, the ratio of these two emission peak was linearly correlated with the Hcy concentration from 5 to 100 μmol/L. The detection limits was 1 μmol/L. The detection of Hcy used the ratio of the two emission peaks, which permit selective detection of Hcy and quantitive determination of Hcy levels.
