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1.
Org Biomol Chem ; 19(27): 6120-6126, 2021 07 21.
Article in English | MEDLINE | ID: mdl-34179916

ABSTRACT

By using a charcoal supported nano Cu0 catalyst (Cu/C), a highly efficient oxidation of α-diazo esters to α-ketoesters with molecular oxygen as the sole oxidant has been developed. In the presence of the Cu/C catalyst, 2-aryl-α-diazo esters with both electron-donating and electron-withdrawing groups can be oxidized to the corresponding α-ketoesters efficiently. Furthermore, this Cu/C catalyst can catalyse the reaction of aryl α-diazo ester with water to form aryl ketoester, 2-aryl-2-hydroxyl acetate ester and 2-aryl acetate ester. In this case, water is split by α-diazo ester, and the diazo group is displaced by the oxygen or hydrogen atom in water. Mechanistic investigation showed that the reaction of α-diazo ester with oxygen proceeds through a radical pathway. In the presence of 2,2,6,6-tetramethyl piperidine nitrogen oxide, the reaction of α-diazo ester with oxygen is dramatically inhibited. Furthermore, the reaction of α-diazo ester with water is investigated by an isotopic tracer method, and GCMS detection showed that a disproportionation reaction occurred between α-diazo ester and water.

2.
Talanta ; 178: 195-201, 2018 Feb 01.
Article in English | MEDLINE | ID: mdl-29136812

ABSTRACT

Crown ether is a type of typical macrocyclic polyether compounds, which can produce strong interactions with cationic species, such as metal ions and protonated amines due to its cavity structure and the strong electronegative effect of heteroatoms on the crown ether ring. In this paper, a type of silica based crown ether stationary phase was prepared by covalently bonding dibenzo-18-crown 6-ether (DBCE) on silica gel via copper (I) catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC). The tetraazido DBCE was rapidly prepared by bromomethylation and subsequent azido substitution of DBCE. Finally, this key intermediate was covalently bonded to silica beads by click chemistry to get click-DBCE. Its structure was confirmed by FT-IR and elemental analysis, and the structures of all related intermediates were confirmed by NMR, IR and MS spectra. The crown ether based stationary phase showed good chromatography characteristics and column efficiency (up to 43,553 plates m-1 theoretical plate number is obtained in the case of fluoranthene) under reverse phase liquid chromatographic (RPLC) model. The primary chromatographic evaluation showed that click-DBCE displayed better chromatography efficiency than commercial C18 stationary phase (THERMO BDS HYPERSIL), when they were applied in the separation of regio-isomers of benzene, polycyclic aromatic hydrocarbons (PAHs) and macrolide pharmaceuticals. Furthermore, this stationary phase could also be used to separate fullerenes under normal phase mode, and in this case, 1-chloronaphthalene was suitable additive for improving chromatographic separation ability.

3.
Anal Bioanal Chem ; 407(20): 6217-20, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26022095

ABSTRACT

A silica-based stationary phase bearing both hydrophilic hydroxyl and amino groups was developed by covalently bonding a small molecular N,N-dimethylamino 1,3-propanediol moiety onto silica beads via copper(I)-catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition (CuAAC). This new stationary phase showed good HILIC characteristics and high column efficiency (the theoretical plate number is up to 37000 plates m(-1) in the case of inosine) in the separation of polar compounds, such as nucleosides and bases, organic acids, cephalosporins, and carbapenems.


Subject(s)
Carbapenems/isolation & purification , Cephalosporins/isolation & purification , Chromatography, High Pressure Liquid/methods , Propylene Glycols/chemistry , Silicon Dioxide/chemistry , Alkynes/chemistry , Azides/chemistry , Cycloaddition Reaction
4.
ACS Comb Sci ; 17(3): 147-51, 2015 Mar 09.
Article in English | MEDLINE | ID: mdl-25629450

ABSTRACT

A new one-pot, three component reaction involving the use of Julia reagent, aldehyde, and sodium azide was developed for the efficient synthesis of N-unsubstituted 1,2,3-triazoles. This reaction could be carried out under mild reaction conditions without any precaution, and broad scope of substrates, both respect to Julia reagents and aldehydes, could be applied in this reaction system in generation of a small library of title compounds.


Subject(s)
Ammonium Compounds/chemistry , Triazoles/chemical synthesis , Molecular Structure , Solvents/chemistry , Triazoles/chemistry , Wettability
5.
Talanta ; 132: 137-45, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25476290

ABSTRACT

Iminodiacetic acid (IDA) is dicarboxylic acid amine, which may produce stronger interaction with polar or charged compounds than bidentate α,ß-amino acid. In this article, a novel type of tridentate zwitterionic HILIC stationary phase was prepared by covalently bonding N-benzyl IDA on silica gel via copper(I) catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition (CuAAC). The structure of this stationary phase and all related intermediates was confirmed by NMR, FT-IR, MS spectrum and elemental analysis. The new stationary phase showed good HILIC characteristics and high column efficiency (the theoretical plate number is up to 44000 plates m(-1) in the case of guanosine) in the application of separation of polar compounds, including organic acids, organic bases, as well as highly polar and hydrophilic compounds, such as cephalosporins and carbapenems. Most of them displayed good peak shape and selectivity.


Subject(s)
Carbapenems/isolation & purification , Cephalosporins/isolation & purification , Chromatography, Liquid/methods , Imino Acids/chemistry , Silica Gel/chemistry , Alkynes/chemistry , Azides/chemistry , Benzoates/isolation & purification , Click Chemistry , Cycloaddition Reaction , Hydrophobic and Hydrophilic Interactions , Purines/isolation & purification , Pyrimidines/isolation & purification , Solutions , Sulfadiazine/isolation & purification
6.
Org Lett ; 16(2): 350-3, 2014 Jan 17.
Article in English | MEDLINE | ID: mdl-24392889

ABSTRACT

A practical, convenient, and cheap copper-catalyzed aerobic oxidative coupling of aromatic alcohols and acetonitrile to ß-ketonitriles has been developed. The green C-C bond formation involving the loss of two hydrogen atoms from the corresponding two carbons, respectively, unlocks opportunities for markedly different synthetic strategies.


Subject(s)
Alcohols/chemistry , Copper/chemistry , Ketones/chemical synthesis , Nitriles/chemical synthesis , Catalysis , Hydrogen , Ketones/chemistry , Molecular Structure , Nitriles/chemistry , Oxidative Coupling
7.
Talanta ; 115: 129-32, 2013 Oct 15.
Article in English | MEDLINE | ID: mdl-24054569

ABSTRACT

A novel amide stationary phase (ASP) for hydrophilic interaction liquid chromatography (HILIC) has been prepared via the Click chemistry method. It was based on the strategy that the amino group of Asparagine was easily transferred to the corresponding azido group and then clicked onto terminal alkyne-silica gel in the presence of Cu(I)-based catalyst. For the tested polar compounds including nucleosides and nucleic acid bases, ASP-based column has demonstrated good performance in terms of separation efficiency and column stability, and the retention mechanism was found to match well the typical HILIC retention. In addition, the ASP described here showed much better selectivity in separation of inorganic anions under ion chromatography mode relative to other kinds of commercial ASP.


Subject(s)
Asparagine/chemistry , Chromatography, Ion Exchange/methods , Chromatography, Liquid/methods , Nucleosides/isolation & purification , Purine Nucleotides/isolation & purification , Pyrimidine Nucleotides/isolation & purification , Alkynes/chemistry , Catalysis , Cations, Monovalent , Chromatography, Ion Exchange/instrumentation , Chromatography, Liquid/instrumentation , Click Chemistry , Copper/chemistry , Gels , Hydrophobic and Hydrophilic Interactions , Silicon Dioxide/chemistry
8.
Org Biomol Chem ; 11(23): 3776-80, 2013 Jun 21.
Article in English | MEDLINE | ID: mdl-23657786

ABSTRACT

A new strategy for synthesis of imines using the approach of release of H2 has been developed. This oxidant- and acceptor-free Pd/C catalysis protocol is further applied to synthesis of benzoxazoles, benzimidazoles, and benzothiazoles through a one-pot cascade reaction with notably high yields.

9.
Analyst ; 137(7): 1624-8, 2012 Apr 07.
Article in English | MEDLINE | ID: mdl-22343922

ABSTRACT

A silica based amino stationary phase was prepared by immobilization of propargylamine on azide-silica via click chemistry. This readily prepared click amino stationary phase demonstrated good selectivity in separation of common inorganic anions under ion chromatography (IC) mode, and the triazole ring in combination with free amino group was observed to play a major role for separation of the anions examined. On the other hand, the stationary phase also showed good hydrophilic interaction liquid chromatography (HILIC) properties in the separation of polar compounds including nucleosides, organic acids and bases. The retention mechanism was found to match well the typical HILIC retention.


Subject(s)
Amino Acids/chemistry , Chromatography, High Pressure Liquid/methods , Chromatography, Ion Exchange/methods , Click Chemistry , Silicon Dioxide/chemistry , Triazoles/chemistry , Hydrophobic and Hydrophilic Interactions , Molecular Structure
10.
J Chromatogr A ; 1223: 47-52, 2012 Feb 03.
Article in English | MEDLINE | ID: mdl-22226552

ABSTRACT

A novel type of zwitterionic HILIC stationary phase was prepared by covalently bonding the l-azido lysine on silica gel via click chemistry. The key intermediate azido lysine was synthesized by transformation the amino group in l-Boc-lysine to corresponding azido group and subsequent removal of the N-protected group (Boc). Finally, the azido lysine was covalently bonded to silica beads by click chemistry to get click lysine. Its structure was confirmed by FT-IR and elemental analysis. The new stationary phase showed good HILIC characteristics, when it was applied to separate polar and hydrophilic compounds, such as organic acids, cephalosporins and carbapenems. Compared with the commercial stationary phases, such as Atlantics HILIC and ZIC-HILIC, click lysine displayed better or similar chromatographic behaviors.


Subject(s)
Azides/chemistry , Chromatography, Liquid/methods , Lysine/analogs & derivatives , Silica Gel/chemistry , Azides/chemical synthesis , Click Chemistry , Hydrophobic and Hydrophilic Interactions , Lysine/chemical synthesis , Silica Gel/chemical synthesis
11.
Analyst ; 136(24): 5302-7, 2011 Dec 21.
Article in English | MEDLINE | ID: mdl-22025231

ABSTRACT

Ion chromatography (IC) is one of the most powerful analysis technologies for the determination of charged compounds. A novel click lysine stationary phase was prepared via Cu(I) catalyzed alkyne-azide 1,3-dipolar cycloaddition (CuAAC) and applied to the analysis of inorganic ions. The chromatographic evaluation demonstrated good performance (e.g. the plate number of thiocyanate is ∼50,000 plates m(-1)) and effective separation ability for the common inorganic anions with aqueous Na(2)SO(4) eluent. The separation mechanism was observed to be mainly dominated by ion exchange interaction. The retention of these analytes is highly dependent on the pH value of eluent. Compared with the lysine stationary phase prepared via the conventional manner, the click lysine exchanger demonstrated shorter retention time and better ion separation characteristics under the same chromatographic conditions, which is a great advantage for rapid separation and analysis of inorganic ions.


Subject(s)
Chromatography, Ion Exchange , Lysine/chemistry , Silicon Dioxide/chemistry , Alkynes/chemistry , Anions/chemistry , Azides/chemistry , Catalysis , Click Chemistry , Copper/chemistry , Humans , Hydrogen-Ion Concentration , Male , Nitrates/analysis , Saliva/chemistry
12.
Talanta ; 85(3): 1642-7, 2011 Sep 15.
Article in English | MEDLINE | ID: mdl-21807234

ABSTRACT

A novel glycosyl amino acid hydrophilic interaction chromatography (HILIC) stationary phase was prepared via click chemistry. The key intermediate N(3)-glycosyl D-phenylglycine was prepared by a three steps procedure, including selective condensation of amino glucose with N-succinimidyl ester of Boc-D-phenylglycine, deprotection and transformation of amino group to azido group. The structure of all the intermediates and functionalized silica beads were confirmed by (1)H NMR, IR, elemental analysis and (13)C CP-MAS. The chromatography test showed that this new type of separation material possessed good HILIC properties and glycopeptide enrichment characteristics. Nucleosides and bases could be separated in a simple eluent composition (only acetonitrile in combined with water), and with the same condition, these model compounds could not be separated on the commercial HILIC column (Atlantis). Click glycosyl amino acid thus prepared also showed longer retention and better separation ability in the separation of polar organic acids.


Subject(s)
Amino Acids/chemistry , Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Glycopeptides/chemistry , Acetonitriles/chemistry , Glycopeptides/chemical synthesis , Glycosylation , Humans , Hydrophobic and Hydrophilic Interactions , Immunoglobulin G/analysis , Immunoglobulin G/chemistry , Immunoglobulin G/isolation & purification , Models, Chemical , Molecular Structure , Nucleosides/analysis , Nucleosides/chemistry , Nucleosides/isolation & purification , Purines/analysis , Purines/chemistry , Purines/isolation & purification , Pyrimidines/analysis , Pyrimidines/chemistry , Pyrimidines/isolation & purification , Reproducibility of Results
13.
J Hazard Mater ; 192(3): 1186-91, 2011 Sep 15.
Article in English | MEDLINE | ID: mdl-21752540

ABSTRACT

Green and cost-effective eradication of pollutants from water is an important and long-standing goal in environmental chemistry. A broad spectrum of toxic organics in water was efficiently destroyed in the presence of dioxygen in combination with hydrazine hydrate at 150 °C. Under this operating condition, two typical classes of toxic organic chemicals, phenols and nitrobenzene derivatives were totally destroyed. The mineralization rate of these organics was 35-86%. Furthermore, when this degradation system was applied to degradation of actual waste water of wood pulp bleaching with chlorine (COD: 1830 mg/L), 77% COD decrease and 52% TOC mineralization of the wastewater were observed. In each case, the major degradation products are small molecular compounds, such as methanol, formic acid and acetic acid except CO/CO(2). In the case of chlorophenols degradation, no dioxins and any other toxic compounds are detected by (1)H NMR. After degradation reaction, the hydrazine was also decomposed into N(2) and H(2)O, and no remaining hydrazine is found.


Subject(s)
Hydrazines/chemistry , Organic Chemicals/chemistry , Oxygen/chemistry , Water Purification/methods , Water/chemistry , Acetic Acid/analysis , Chlorine/analysis , Chlorophenols/chemistry , Formates/analysis , Gas Chromatography-Mass Spectrometry/methods , Hydrazines/analysis , Magnetic Resonance Spectroscopy/methods , Methanol/analysis , Organic Chemicals/analysis , Temperature , Water Pollutants, Chemical/analysis , Wood
14.
Chem Soc Rev ; 40(5): 2177-88, 2011 May.
Article in English | MEDLINE | ID: mdl-21212875

ABSTRACT

With the increasing requirement for analysis and separation of samples related to genomics, proteomics, metabolomics, pharmacology and agrochemistry, diverse stationary phases for liquid chromatography have been prepared by Cu(i)-catalyzed 1, 3-dipolar azide-alkyne cycloaddition reaction (CuAAC). It has been proved that CuAAC is a powerful tool for preparing covalently bonded stationary phases. In this tutorial review, we highlighted the preparation of separation materials by immobilization of functional groups on silica beads, polymer beads and agarose via CuAAC and their applications in liquid chromatography and related purposes, such as separation of polar compounds, enrichment of valuable bio-samples, orthogonal two-dimensional HPLC and chiral separation. Meanwhile, agarose-based separation materials for affinity chromatography are reviewed.


Subject(s)
Chromatography, Liquid/instrumentation , Click Chemistry , Alkynes/chemistry , Azides/chemistry , Catalysis , Chromatography, Liquid/methods , Copper/chemistry , Polymers/chemistry , Sepharose/chemistry , Silicon Dioxide/chemistry , Stereoisomerism
16.
J Chromatogr A ; 1216(49): 8623-9, 2009 Dec 04.
Article in English | MEDLINE | ID: mdl-19863966

ABSTRACT

2D-HPLC is an important technique for the separation of complex samples. Developing new types of stationary phases is of great interest to construct 2D-LC systems with high orthogonality. In this study, a novel stationary phase-Click dipeptide (l-phenylglycine dipeptide) was prepared by immobilization of alpha-azido l-phenylglycine dipeptide on alkyne-silica via click chemistry. In the preparation of this new material, an efficient, inexpensive and shelf-stable diazo transfer reagent (imidazole-1-sulfonyl azide hydrochloride) was utilized to transfer the amino group of l-phenylglycine to corresponding azido group under mild conditions. The Click dipeptide thus prepared was confirmed by FT-IR, solid state CP/MAS (13)C NMR and elemental analysis. The Click dipeptide packing showed high orthogonality with C18, which reached 63.5%. An off-line 2D-RP/RPLC system was developed to analyze a traditional Chinese medicine (TCM)-Rheum Palmatum L. The results showed high orthogonality between Click dipeptide and C18 as well as great separating power in the practical separation of complex samples.


Subject(s)
Chromatography, High Pressure Liquid/instrumentation , Dipeptides/chemistry , Chromatography, High Pressure Liquid/methods , Rheum/chemistry
17.
J Asian Nat Prod Res ; 7(1): 1-5, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15621594

ABSTRACT

A highly unsaturated new amide, (2E,4Z,8Z,10Z)-N-isobutyl-2,4,8,10-dodecatetraenamide (1), was isolated in very small quantities from the whole plant of Asarum forbesii Maxim. together with four known compounds, (2E,4E,8Z,10E)-N-isobutyl-2,4,8,10-dodecatetraenamide (2), (-)-sesamin (3), (-)-asarinin (4) and (E)-asarone (5). The Z/E isomers, 1 and 2, were separated successfully by developed silver-ion medium-pressure liquid chromatography (SIMPLC). Compound 2 and the two diastereoisomers, 3 and 4, were isolated from this plant for the first time. The characterization of these compounds was achieved by various spectroscopic methods.


Subject(s)
Amides/isolation & purification , Asarum/chemistry , Amides/chemistry , Magnetic Resonance Spectroscopy
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