C:Corrosive;
142-62-1Relevant articles and documents
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Morton,Richardson
, p. 123,125,129,130 (1940)
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Hill,Hill
, p. 4591 (1953)
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Komori,Ueno
, p. 226 (1937)
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Alkoxy-1,3,5-triazapentadien(e/ato) copper(II) complexes: Template formation and applications for the preparation of pyrimidines and as catalysts for oxidation of alcohols to carbonyl products
Kopylovich, Maximilian N.,Karabach, Yauhen Yu.,Guedes Da Silva, M. Fatima C.,Figiel, Pawel J.,Lasri, Jamal,Pombeiro, Armando J. L.
, p. 899 - 914 (2012)
Template combination of copper acetate (Cu(AcO)2·H 2O) with sodium dicyanamide (NaN(C≡N)2, 2 equiv) or cyanoguanidine (N≡CNHC(=NH)NH2, 2 equiv) and an alcohol ROH (used also as solvent) leads to the neutral copper(II)-(2,4-alkoxy-1,3,5- triazapentadienato) complexes [Cu{NH=C(OR)NC(OR)=NH}2] (R=Me (1), Et (2), nPr (3), iPr (4), CH2CH2OCH3 (5)) or cationic copper(II)-(2-alkoxy-4-amino-1,3,5-triazapentadiene) complexes [Cu{NH=C(OR)NHC(NH2)=NH}2](AcO)2 (R=Me (6), Et (7), nPr (8), nBu (9), CH2CH2OCH3 (10)), respectively. Several intermediates of this reaction were isolated and a pathway was proposed. The deprotonation of 6-10 with NaOH allows their transformation to the corresponding neutral triazapentadienates [Cu{NH=C(OR)NC(NH 2)=NH}2] 11-15. Reaction of 11, 12 or 15 with acetyl acetone (MeC(=O)CH2C(=O)Me) leads to liberation of the corresponding pyrimidines NC(Me)CHC(Me)NCNHC(=NH)OR, whereas the same treatment of the cationic complexes 6, 7 or 10 allows the corresponding metal-free triazapentadiene salts {NH2C(OR)=NC(NH2)=NH 2}(OAc) to be isolated. The alkoxy-1,3,5-triazapentadiene/ato copper(II) complexes have been applied as efficient catalysts for the TEMPO radical-mediated mild aerobic oxidation of alcohols to the corresponding aldehydes (molar yields of aldehydes of up to 100% with >99% selectivity) and for the solvent-free microwave-assisted synthesis of ketones from secondary alcohols with tert-butylhydroperoxide as oxidant (yields of up to 97%, turnover numbers of up to 485 and turnover frequencies of up to 1170 h-1). One pot for the lot: Alkoxy-1,3,5-triazapentadien(e/ato)-CuII complexes have been synthesised by one-pot template synthesis, used for metal-mediated synthesis of pyrimidines and triazapentadienes, and shown to be effective catalysts in the oxidation of alcohols to carbonyl products (see scheme). Copyright
MULTIFUNCTIONAL MICELLAR CATALYSIS AS A MODEL OF ENZYME ACTION.
Ihara,Nango,Kimura,Kuroki
, p. 1252 - 1255 (1983)
The rate constants of both the acylation and deacylation processes in the hydrolyses of p-nitrophenyl acetate (PNPA) and hexanoate (PNPH) by imidazole catalysts (1) in the presence of surfactant micelles (2) have been directly determined under single turnover conditions at pH 7. 30 in 0. 02 M phosphate buffer and 25 degree C. The major course of catalysts was the acylation followed by deacylation at the imidazole group. The kinetic analysis suggests that a multifunctional mode of action is involved in the catalystic ester hydrolysis; the acylation and deacylation rates are accelerated by carboxylate ion in the catalyst and by surfactant hydroxyl group, respectively.
Two-fold interpenetrating btc based cobaltous coordination polymer: A promising catalyst for solvent free oxidation of 1-hexene
Bora, Sanchay J.,Paul, Rima,Nandi, Mithun,Bhattacharyya, Pradip K.
, p. 38 - 44 (2017)
This work describes the synthesis of a new 2-D coordination polymer (CP), [Co3(btc)2(dmp)8]n (btc = 1,3,5-benzenetricarboxylate and dmp = 3,5-dimethylpyrazole) and its catalytic activity towards the oxidation reaction of 1-hexene to form oxygenated compounds under solvent free condition. Structural analysis reveals that Co(II) cations in this polymeric compound are linked by btc3- anions with alternate tetrahedral/octahedral coordination forming a two-fold interpenetrated 3-connected hcb underlying net. Electronic spectrum of the cobaltous polymer has been calculated using TDDFT/B3LYP method for making the appropriate assignments of electronic transitions. Catalytic results show good conversions of the starting material to oxygenated products with high selectivities for 1,2-epoxyhexane and 1-hexanal.
Antioxidative activity of heterocyclic compounds found in coffee volatiles produced by Maillard reaction
Yanagimoto, Kenichi,Lee, Kwang-Geun,Ochi, Hirotomo,Shibamoto, Takayuki
, p. 5480 - 5484 (2002)
Typical heterocyclic compounds substituted with various functional groups found in Maillard reaction products were examined for antioxidant activity. Pyrroles exhibited the greatest antioxidant activity among all heterocyclic compounds tested. All pyrroles inhibited hexanal oxidation by almost 100% at a concentration of 50 μg/mL over 40 days. Addition of formyl and acetyl groups to a pyrrole ring enhanced antioxidative activity remarkably. Pyrrole-2-carboxaldehyde, 2-acetylpyrrole, 1-methyl-2-pyrrolecarboxaldehyde, and 2-acetyl-1-methylpyrrole inhibited hexanal oxidation by >80% at 10 μg/mL. Unsubstituted furan exhibited the greatest antioxidant activity among furans tested. Addition of all functional groups used in this study to furan decreased antioxidative activity. The antioxidant activity of thiophene increased with the addition of methyl and ethyl groups, but the addition of formyl or acetyl groups to thiophene decreased antioxidant activity. Thiazoles and pyrazines were ineffective antioxidants at all concentrations tested. Reaction of all heterocyclic compounds with hydrogen peroxide resulted in the formation of various oxidized products.
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Gilman,Pacevitz
, p. 1301,1302 (1940)
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Biotransformation of linoleic acid into hydroxy fatty acids and carboxylic acids using a linoleate double bond hydratase as key enzyme
Oh, Hye-Jin,Kim, Sae-Um,Song, Ji-Won,Lee, Jung-Hoo,Kang, Woo-Ri,Jo, Ye-Seul,Kim, Kyoung-Rok,Bornscheuer, Uwe T.,Oh, Deok-Kun,Park, Jin-Byung
, p. 408 - 416 (2015)
Hydroxy fatty acids are used as starting materials for the production of secondary metabolites and signalling molecules as well as in the manufacture of industrial fine chemicals. However, these compounds are usually difficult to produce from renewable biomass by chemical means. In this study, linoleate double bond hydratases of Lactobacillus acidophilus NBRC 13951 were cloned for the first time. These enzymes were highly specific for the hydration of the C-9 or the C-12 double bond of unsaturated fatty acids (e.g., linoleic acid). Thereby, the enzymes allowed the selective production of hydroxy fatty acids such as 13-hydroxy- cis -9-octadecenoic acid and 10-hydroxy- cis -12-octadecenoic acid from linoleic acid. In addition, the hydroxy fatty acids were further converted into industrially relevant carboxylic acids (e.g., 12-hydroxy-cis-9-dodecenoic acid, a, w-tridec-9-enedioic acid) and lactones (i.e., d-decalactone, g-dodecelactone) via whole-cell biocatalysis using an enzyme cascade. This study thus contributes to the preparation of hydroxy fatty acids, unsaturated carboxylic acids, and lactones from renewable unsaturated fatty acids.
Farmer,Galley
, p. 60 (1933)
Electro-oxidative Neutral Deprotection of S-t-Butyl Thioates to give Carboxylic Acids
Kimura, Makoto,Matsubara, Shinichi,Sawaki, Yasuhiko
, p. 1619 - 1620 (1984)
t-Butyl thioates are proposed as a convenient protecting group for carboxylic acids, because their deprotection under neutral conditions can be attained by electro-oxidation using bromide salts as electrolytes in aqueous acetonitrile.
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Benz,Biemann
, p. 2375,2376 (1964)
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Aqueous Persistent Noncovalent Ion-Pair Cooperative Coupling in a Ruthenium Cobaltabis(dicarbollide) System as a Highly Efficient Photoredox Oxidation Catalyst
Guerrero, Isabel,Vi?as, Clara,Fontrodona, Xavier,Romero, Isabel,Teixidor, Francesc
, p. 8898 - 8907 (2021/06/28)
An original cooperative photoredox catalytic system, [RuII(trpy)(bpy)(H2O)][3,3′-Co(1,2-C2B9H11)2]2 (C4; trpy = terpyridine and bpy = bipyridine), has been synthesized. In this system, the photoredox metallacarborane catalyst [3,3′-Co(1,2-C2B9H11)2]- ([1]-) and the oxidation catalyst [RuII(trpy)(bpy)(H2O)]2+ (C2′) are linked by noncovalent interactions and not through covalent bonds. The noncovalent interactions to a large degree persist even after water dissolution. This represents a step ahead in cooperativity avoiding costly covalent bonding. Recrystallization of C4 in acetonitrile leads to the substitution of water by the acetonitrile ligand and the formation of complex [RuII(trpy)(bpy)(CH3CN)][3,3′-Co(1,2-C2B9H11)2]2 (C5), structurally characterized. A significant electronic coupling between C2′ and [1]- was first sensed in electrochemical studies in water. The CoIV/III redox couple in water differed by 170 mV when [1]- had Na+ as a cation versus when the ruthenium complex was the cation. This cooperative system leads to an efficient catalyst for the photooxidation of alcohols in water, through a proton-coupled electron-transfer process. We have highlighted the capacity of C4 to perform as an excellent cooperative photoredox catalyst in the photooxidation of alcohols in water at room temperature under UV irradiation, using 0.005 mol % catalyst. A high turnover number (TON = 20000) has been observed. The hybrid system C4 displays a better catalytic performance than the separated mixtures of C2′ and Na[1], with the same concentrations and ratios of Ru/Co, proving the history relevance of the photocatalyst. Cooperative systems with this type of interaction have not been described and represent a step forward in getting cooperativity avoiding costly covalent bonding. A possible mechanism has been proposed.
Catalytic hydrogenation of sorbic acid using pyrazolyl palladium(II) and nickel(II) complexes as precatalysts
Darkwa, James,Kumar, Gopendra,Makhubela, Banothile C. E.,Muyaneza, Apollinaire,Olaoye, Oluwasegun E.,Oyetunji, Olayinka
, p. 50 - 56 (2021/12/09)
We have prepared several pyrazolyl palladium and nickel complexes ([(L1)PdCl2] (1), [(L2) PdCl2] (2), [(L3) PdCl2] (3), [(L1) NiBr2] (4), [(L2) NiBr2] (5) and [(L3) NiBr2] (6)) by reacting 3,5-dimethyl-1H-pyrazole (L1), 3,5-di-tert-butyl-1H-pyrazole (L2) and 5-ferrocenyl-1H-pyrazole(L3) with [PdCl2(NCMe)2] or [NiBr2(DME)] to afford mononuclear palladium and nickel complexes, respectively. These complexes were then investigated as pre-catalysts in the hydrogenation of 2,4-hexadienoic acid (sorbic acid). The active catalysts from these complexes demonstrate significant activities under mild experimental conditions. Additionally, the active catalysts show that the hydrogenation of sorbic acid proceeds in a sequential manner, where the less hindered C=C bond (4-hexenoic acid) is preferentially reduced over the more hindered C=C bond (2-hexenoic acid).
