scholarly journals Triethylammonium halochromates/silica gel: an efficient reagent for oxidative coupling of thiols to disulfides

2008 ◽  
Vol 27 (2) ◽  
pp. 117 ◽  
Author(s):  
Shahriare Ghammamy ◽  
Mohammad Kazem Mohammadi ◽  
Ali Hassani Joshaghani
Keyword(s):  
Hydrochloric Acid ◽  
Silica Gel ◽  
Oxidative Coupling ◽  
Hydrofluoric Acid ◽  
Organic Substrates ◽  
Reaction Conditions ◽  
Chromium Vi ◽  
Aromatic Thiols ◽  
Efficient Reagent ◽  
Versatile Reagent

Triethylammonium halochromates, (C2H5)3NCrO3X, TEAXC (X = Cl, F) are easily synthesized by the reaction of triethylamine with a solution of chromium(VI) oxide in 6M hydrochloric acid, or a solution of chromium(VI) oxide in 40% hydrofluoric acid. These reagents are easily supported on common silica gel and can be used as heterogeneous oxidants. Triethylammonium halochromate(VI) is a versatile reagent for the effective and selective oxidation of organic substrates. Various aliphatic (cyclic and acyclic) and aromatic thiols are converted into the corresponding disulfides by treatment with triethylammonium fluorochromate(VI), (TEACC) or triethylammonium chlorochromate(VI), (TEAFC) supported on silica gel, in excellent yields and under mild reaction conditions.

scholarly journals Tributylammonium chlorochromate, (C4H9)3NH[CrO3Cl] (TriBACC): A new, mild and stable oxidant for organic substrates

2005 ◽  
Vol 70 (5) ◽  
pp. 687-693 ◽  
Author(s):  
S. Ghammamy ◽  
M. Mazareey
Keyword(s):  
Hydrochloric Acid ◽  
Selective Oxidation ◽  
Quantitative Yield ◽  
Organic Substrates ◽  
Mild Conditions ◽  
Chromium Vi ◽  
Versatile Reagent

Amild and stable new chromium(VI) reagent from tributylamine is described. Orange crystalline tributylammonium chlorochromate(VI), (C4H9)3NH[CrO3Cl], (TriBACC), is easily prepared in a nearly quantitative yield by the interaction of tributylamine with CrO3 and hydrochloric acid in a 1:2:2 mole ratio. This reagent is a versatile reagent for the effective and selective oxidation of organic substrates, in particular for alcohols, under mild conditions.

scholarly journals Tetrabutylammonium fluorochromate(VI)(TBFAC): A mild and efficient reagent for oxidation of organic substrates

2005 ◽  
Vol 70 (11) ◽  
pp. 1243-1248 ◽  
Author(s):  
Shahriare Ghammami ◽  
Seyed Sajadi
Keyword(s):  
Selective Oxidation ◽  
Oxygen Transfer ◽  
Transfer Reaction ◽  
Triphenylphosphine Oxide ◽  
Organic Substrates ◽  
Mild Conditions ◽  
Tetrabutylammonium Fluoride ◽  
Efficient Reagent ◽  
Versatile Reagent

Orange solid tetrabutylammonium fluorochromate, (C4H9)4NCrO3F, TBAFC, is easily synthesized by the reaction of tetrabutylammonium fluoride with CrO3 in a 1:1 mole ratio. Tetrabutylammonium fluorochromate(VI) is a versatile reagent for the effective and selective oxidation of organic substrates, in particular of alcohols, under mild conditions. The facile oxidation of triphenylphosphine to triphenylphosphine oxide by TBAFC in CH3CN provides clear evidence for an oxygen-transfer reaction. .

An Unprecedented Cyano-Induced Sodium Nitrite-Catalyzed C(sp3)-H and C(sp2)-H Coupling Reaction

2018 ◽  
Vol 15 (7) ◽  
pp. 989-994 ◽  
Author(s):  
Ling Li ◽  
Bo Su ◽  
Yuxiu Liu ◽  
Qingmin Wang
Keyword(s):  
Sodium Nitrite ◽  
Oxidative Coupling ◽  
High Resolution Mass Spectrometry ◽  
Coupling Reaction ◽  
13C Nmr Spectroscopy ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
1H And 13C Nmr ◽  
Oxidative Coupling Reaction ◽  
Oxidative Coupling Reactions

Aim and Objective: During the investigation of sodium nitrite-catalyzed oxidative coupling reaction of aryls, an unprecedented C(sp2)-H and C(sp3)-H coupling of substituted 2-aryl acetonitrile was found. Materials and Methods: The structure of the coupled product was confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS), and comparison of its derivatives with known compounds. The effects of methoxy group in the benzene ring on the reaction were evaluated. Results: The optimized reaction conditions are summarized as follows: CF3SO3H/substrate = 1.5 equiv., NaNO2/substrate = 0.3 equiv., CH3CN as solvent. 2-(4-Methoxyphenyl)acetonitrile and 2-(3,4,5- trimethoxyphenyl)acetonitrile could also generate C(sp2)-H and C(sp3)-H coupling. The coupling reaction occurred as a typical radial mechanism. Conclusion: An unprecedented cyano-induced, NaNO2-catalyzed oxidative C(sp3)-H and C(sp2)-H coupling was reported. The reaction proceeded under very mild conditions, using O2 in the air as terminal oxidant. The unique oxidative manner might provide more inspiration for the development of intriguing oxidative coupling reactions.

Sequestered uptake of chromium(VI) by Irvingia gabonensis stem bark extract anchored silica gel

2021 ◽  
Author(s):  
James F. Amaku ◽  
Segun A. Ogundare ◽  
Kovo G. Akpomie ◽  
Comfort M. Ngwu ◽  
Jeanet Conradie
Keyword(s):  
Silica Gel ◽  
Stem Bark ◽  
Bark Extract ◽  
Chromium Vi ◽  
Irvingia Gabonensis ◽  
Stem Bark Extract

Efficient and Reusable Silica Gel Supported Metal Ionic Liquid Catalysts for Palmitic Acid Esterification to Biodiesel

2021 ◽  
Vol 43 (1) ◽  
pp. 1-1
Author(s):  
Guo Yingwei Guo Yingwei ◽  
Chen Xuedan Chen Xuedan ◽  
Yan Shiting Yan Shiting ◽  
Zhang Zhengliang Zhang Zhengliang ◽  
Chen Yuqin Chen Yuqin ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Palmitic Acid ◽  
Silica Gel ◽  
High Surface ◽  
High Surface Area ◽  
Kinetic Studies ◽  
Catalytic Performance ◽  
Reaction Conditions ◽  
Acid Esterification ◽  
Supported Metal

A series of silica gel (SG) supported metal ionic liquid catalysts (x[Bmim]Cl-CrCl3/SG) were synthesized and exploited for the esterification of palmitic acid (PA) with methanol (ML) to produce biodiesel efficiently. The 10%[Bmim]Cl-CrCl3/SG catalyst with high surface area and desirable acidity exhibited the best catalytic performance and reusability after six consecutive running cycles. Based on the response surface analysis, the optimal reaction conditions were obtained as follows: methanol/acid mole ratio = 11:1 mol/mol, catalyst amount = 5.3 wt%, reaction time = 65 min, as well as reaction temperature = 373 K, reaching to a biodiesel yield of 96.1%. Further kinetic studies demonstrated that the esterification of PA with ML obeyed 1.41 order kinetics for acid concentration with the activation energy of 16.88 kJ/mol

ChemInform Abstract: Tributylammonium Halochromates/Silica Gel: Simple Reagents for Oxidative Coupling of Thiols to Symmetrical Disulfides.

ChemInform ◽  
2011 ◽  
Vol 42 (12) ◽  
pp. no-no
Author(s):  
Mohammad Kazem Mohammadi ◽  
Shahriare Ghammamy ◽  
Soroush Zarrinabadi ◽  
Mohammad Hossein Farjam ◽  
Behrang Sabayan
Keyword(s):  
Silica Gel ◽  
Oxidative Coupling ◽  
Symmetrical Disulfides

Efficient and Reusable Silica Gel Supported Metal Ionic Liquid Catalysts for Palmitic Acid Esterification to Biodiesel

2021 ◽  
Vol 43 (1) ◽  
pp. 1-1
Author(s):  
Guo Yingwei Guo Yingwei ◽  
Chen Xuedan Chen Xuedan ◽  
Yan Shiting Yan Shiting ◽  
Zhang Zhengliang Zhang Zhengliang ◽  
Chen Yuqin Chen Yuqin ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Palmitic Acid ◽  
Silica Gel ◽  
High Surface ◽  
High Surface Area ◽  
Kinetic Studies ◽  
Catalytic Performance ◽  
Reaction Conditions ◽  
Acid Esterification ◽  
Supported Metal

A series of silica gel (SG) supported metal ionic liquid catalysts (x[Bmim]Cl-CrCl3/SG) were synthesized and exploited for the esterification of palmitic acid (PA) with methanol (ML) to produce biodiesel efficiently. The 10%[Bmim]Cl-CrCl3/SG catalyst with high surface area and desirable acidity exhibited the best catalytic performance and reusability after six consecutive running cycles. Based on the response surface analysis, the optimal reaction conditions were obtained as follows: methanol/acid mole ratio = 11:1 mol/mol, catalyst amount = 5.3 wt%, reaction time = 65 min, as well as reaction temperature = 373 K, reaching to a biodiesel yield of 96.1%. Further kinetic studies demonstrated that the esterification of PA with ML obeyed 1.41 order kinetics for acid concentration with the activation energy of 16.88 kJ/mol

An Improved And Suitable Method For Large Scale Produdcion Of Α-Monochlorocyclodecanone

2021 ◽  
Vol 18 ◽  
Author(s):  
Wenhua Ou ◽  
Ruolin Wang ◽  
Ruonan Liu ◽  
Hong Huang
Keyword(s):  
Silica Gel ◽  
Large Scale ◽  
Raw Materials ◽  
Separation Method ◽  
Suitable Method ◽  
Scale Production ◽  
Reaction Conditions ◽  
Environment Friendly ◽  
Large Scale Production ◽  
Ideal Approach

: α-Monochlorocyclododecanone was synthesized from cyclododecane and 1,3-Dichloro-5,5-dimethylhydantoin (DCDMH) catalyzed with silica gel in MeOH. The product was obtained by crystallization with nearly 85% yield. The presented method used cheap raw materials, mild reaction conditions, simple separation method and environment-friendly process. Additionally, the current synthesis provided an ideal approach for large-scale production.

New cobalt(ii) coordination designs and the influence of varying chelate characters, ligand charges and incorporated group I metal ions on enzyme-like oxidative coupling activity

2020 ◽  
Vol 44 (35) ◽  
pp. 14849-14858
Author(s):  
Hammed Olawale Oloyede ◽  
Joseph Anthony Orighomisan Woods ◽  
Helmar Görls ◽  
Winfried Plass ◽  
Abiodun Omokehinde Eseola
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Active Site ◽  
Oxidative Coupling ◽  
Reaction Conditions ◽  
Group I ◽  
Mediated Catalysis

In transition-metal-mediated catalysis, design of new, well defined coordination architectures and subjecting them to catalysis testing under the same reaction conditions is a necessity tool for improved understanding of desirable active site geometries and characteristics.

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