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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STRONGLY LEWIS ACIDIC METAL-ORGANIC FRAMEWORKS FOR CONTINUOUS FLOW CATALYSIS
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, (2021/02/26)
Lewis acidic metal-organic framework (MOF) materials comprising triflate-coordinated metal nodes are described. The materials can be used as heterogenous catalysts in a wide range of organic group transformations, including Diels-Alder reactions, epoxide-ring opening reactions, Friedel-Crafts acylation reactions and alkene hydroalkoxylation reactions. The MOFs can also be prepared with metallated organic bridging ligands to provide heterogenous catalysts for tandem reactions and/or prepared as composites with support particles for use in columns of continuous flow reactor systems. Methods of preparing and using the MOF materials and their composites are also described.
An Anionic, Chelating C(sp3)/NHC ligand from the Combination of an N-heterobicyclic Carbene and Barbituric Heterocycle
Benaissa, Idir,Gajda, Katarzyna,Vendier, Laure,Lugan, No?l,Kajetanowicz, Anna,Grela, Karol,Michelet, Véronique,César, Vincent,Bastin, Stéphanie
, p. 3223 - 3234 (2021/09/30)
The coordination chemistry of the anionic NHC1-based on an imidazo[1,5-a]pyridin-3-ylidene (IPy) platform substituted at the C5 position by an anionic barbituric heterocycle was studied with d6(Ru(II), Mn(I)) and d8(Pd(II), Rh(I), Ir(I), Au(III)) transition-metal centers. While the anionic barbituric heterocycle is planar in the zwitterionic NHC precursor 1·H, NMR spectroscopic analyses supplemented by X-ray diffraction studies evidenced the chelating behavior of ligand 1-through the carbenic and the malonic carbon atoms in all of the complexes, resulting from a deformation of the lateral barbituric heterocycle. The complexes were obtained by reaction of the free carbene with the appropriate metal precursor, except for the Au(III) complex 10, which was obtained by oxidation of the antecedent gold(I) complex [AuCl(1)]?with PhICl2as an external oxidant. During the course of the process, the kinetic gold(I) intermediate 9 resulting from the oxidation of the malonic carbon of the barbituric moiety was isolated upon crystallization from the reaction mixture. The νCOstretching frequencies recorded for complex [Rh(1)(CO)2] (5) demonstrated the strong donating character of the malonate-C(sp3)/NHC ligand 1-. The ruthenium complex [Ru(1)Cl(p-cymene)] (11) was implemented as a precatalyst in the dehydrogenative synthesis of carboxylic acid derivatives from primary alcohols and exhibited high activities at low catalyst loadings (25-250 ppm) and a large tolerance toward functional groups.