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Khadijah M. Al-zaydi - One of the best experts on this subject based on the ideXlab platform.
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Arylhydrazononitriles as precursors to 2-substituted 1,2,3-triazoles and 4-amino-5-cyano-pyrazole derivatives utilizing microwave and ultrasound irradiation
Green Chemistry Letters and Reviews, 2012Co-Authors: Khadijah M. Al-zaydi, Rita M. Borik, Mohamed Hilmy ElnagdiAbstract:Abstract Cyanoacetamides 3a–d were prepared by reacting ethyl cyanoacetate with primary aliphatic amines 2a–d. The formed cyanoacetamides 3a–d were coupled with aromatic diazonium salts to give the corresponding arylhydrazones 4a–i which were used as precursors to title triazoles and pyrazoles by reacting with hydroxylamine and Chloroacetonitrile. Yields of products formed by conventional heating are compared with those of microwave and ultrasound irradiation
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A simplified green chemistry approaches to synthesis of 2-substituted 1,2,3-triazoles and 4-amino-5-cyanopyrazole derivatives conventional heating versus microwave and ultrasound as ecofriendly energy sources.
Ultrasonics sonochemistry, 2009Co-Authors: Khadijah M. Al-zaydiAbstract:Cyanoacetamides 3 were prepared via reacting ethyl cyanoacetate with benzylamine. Yields and reaction times needed for reaction completion at room temperature, by microwaves (μω) heating and under ultrasound (US) irradiations are compared. The formed cyanoacetamides were coupled with aromatic diazonium salts and the formed arylhydrazones were used as precursors to title triazoles and pyrazoles via reacting the former with hydroxylamine and Chloroacetonitrile. Yields of products formed via conventional heating are compared with those of μω and US irradiation.
O. Reynes - One of the best experts on this subject based on the ideXlab platform.
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Electrocatalytic carboxylation of Chloroacetonitrile mediated by a Co(I) phenanthroline complex: Mechanistic and spectroscopic studies
Journal of Electroanalytical Chemistry, 2013Co-Authors: P.-l. Fabre, Dancheng Chen, O. Reynes, Nadia Chouini-lalanne, Valérie SartorAbstract:Abstract Mechanisms implied in the electrocarboxylation of Chloroacetonitrile (Cl–CH 2 –CN, noted RCl) mediated by [Co(II)(phen) 3 ] 2+ have been investigated by cyclic voltammetry and spectroelectrochemistry (UV–Visible and e.p.r.). The studies showed that the oxidative addition of Chloroacetonitrile on the electrogenerated [Co(I)(phen) 2 ] + yields an alkyl-cobalt R-Co(III) complex. This complex can either be reduced into an alkyl-cobalt(II) or undergoes a homolytic cobalt–carbon bond cleavage to form the organic radical R and the [Co(II)(phen) 2 ] 2+ complex. Whatever the process, R − and [Co(I)(phen) 2 ] + were produced. In presence of free phenanthroline, the catalytic behaviour of the complex was strongly vanished because the formation of the active complex [Co(I)(phen) 2 ] + is restricted. Under CO 2 atmosphere, the catalytic electrocarboxylation of Chloroacetonitrile was observed. Bulk electrolyses showed that the carboxylated and faradic yields depended on the applied electrolysis potential and free phenanthroline concentration.
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Electrocarboxylation of Chloroacetonitrile by a Cobalt(I) complex of terpyridine
Electrochimica Acta, 2011Co-Authors: Dancheng Chen, P.-l. Fabre, O. ReynesAbstract:The electrocarboxylation of Chloroacetonitrile (NC–CH2–ClRCl) mediated by [CoIIL2]2+ (L = terpyridine) was investigated by cyclic voltammetry. Electrochemical studies under argon atmosphere showed that the monoelectronic reduction of [CoIIL2]2+ yielded a Cobalt(I) complex which after the loss of a terpyridine ligand reacted with Chloroacetonitrile. The oxidative addition of Chloroacetonitrile on [CoIL]+ gave an alkylCobalt(III) complex [R–CoIIIL]2+ which was reduced into an alkylCobalt(II) complex, highly unstable and decomposed into an alkyl anion and a Cobalt(II) complex. Under carbon dioxide atmosphere, Cobalt(I) complex was shown to be unreactive towards CO2 but CO2 insertion was observed in the alkylCobalt(III) complex [R–CoIIIL] 2+ giving probably a CO2 adduct [R–CoIIIL(CO2)]2+. This adduct presented a strong adsorption at the carbon electrode and was reduced at potential less cathodic than the one of alkylCobalt(III) complex. After reduction, the carboxylate RCO2− (NC–CH2–CO2−) was released and a catalytic bielectronic carboxylation of Chloroacetonitrile took place. Controlled potential electrolyses confirmed the catalytic process and gave for cyanoacetic acid faradic yields up to 60% under low overpotential conditions.
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Electrocarboxylation of Chloroacetonitrile mediated by electrogenerated cobalt(I) phenanthroline
Elsevier, 2010Co-Authors: P.-l. Fabre, O. ReynesAbstract:The electrocarboxylation of Chloroacetonitrile mediated by [Co(II)(phen)3]2+ has been investigated. Cyclic voltammetry studies of [Co(II)(phen)3]2+ have shown that [Co(I)(phen)3]+, an 18 electron complex, activates Chloroacetonitrile by an oxidative addition through the loss of a phenanthroline ligand to give [RCo(III)(phen)2Cl]+. The unstable one-electron-reduced complex underwent Co–C bond cleavage. In carbon dioxide saturated solution, CO2 insertion proceeds after reduction of the alkylcobalt complex. A catalytic current is observed which corresponds to the electrocarboxylation of Chloroacetonitrile into cyanoacetic acid. Electrolyses confirmed the process and gave faradic yield of 62% in cyanoacetic acid at potentials that are about 0.3 V less cathodic than the one required for Ni(salen). Keywords: Electrocarboxylation, Cobalt tris (phenanthroline), Electrocatalysis, Chloroacetonitrile, Cyanoacetic aci
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Electrocarboxylation of Chloroacetonitrile mediated by electrogenerated cobalt(I) phenanthroline
Electrochemistry Communications, 2010Co-Authors: P.-l. Fabre, O. ReynesAbstract:Abstract The electrocarboxylation of Chloroacetonitrile mediated by [Co(II)(phen)3]2+ has been investigated. Cyclic voltammetry studies of [Co(II)(phen)3]2+ have shown that [Co(I)(phen)3]+, an 18 electron complex, activates Chloroacetonitrile by an oxidative addition through the loss of a phenanthroline ligand to give [RCo(III)(phen)2Cl]+. The unstable one-electron-reduced complex underwent Co–C bond cleavage. In carbon dioxide saturated solution, CO2 insertion proceeds after reduction of the alkylcobalt complex. A catalytic current is observed which corresponds to the electrocarboxylation of Chloroacetonitrile into cyanoacetic acid. Electrolyses confirmed the process and gave faradic yield of 62% in cyanoacetic acid at potentials that are about 0.3 V less cathodic than the one required for Ni(salen).
Mohsin Ahmad Bhat - One of the best experts on this subject based on the ideXlab platform.
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Ionic Liquid Induced Enhancement in the Stickiness of Sticky Dissociative Electroreductive CCl Bond Cleavage: A Key to Eco-Green Detoxification of Chloroacetonitrile
Electrochimica Acta, 2016Co-Authors: Sarwar Ahmad Pandit, Mudasir Ahmad Rather, Sajad Ahmad Bhat, Khaliquz Zaman Khan, Pravin P. Ingole, Mohsin Ahmad BhatAbstract:Abstract Detailed voltammetric investigations that demonstrate the potential of 1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM][BF 4 ]), a commonly used room-temperature ionic liquid (RTIL), to enhance the stickiness in the sticky dissociative electrodetoxification pathway for Chloroacetonitrile are presented. Convolution analysis of the voltammetric data in light of the Marcus-Hush formulation reveals that electroreductive cleavage of the C Cl bond of Chloroacetonitrile (ClCH 2 CN) in [BMIM][BF 4 ] follows a sticky dissociative pathway like that in conventional organic solvents. Interestingly the interaction energy between Cl and CNCH 2 (radical) in [BMIM][BF 4 ] is observed to be almost ten times higher than that reported for the same species in N,N -dimethylformamide (DMF). This RTIL-induced enhancement in the interaction energy among the electrochemically generated fragments reduces the kinetic barrier and hence the overpotential required for heterogeneous electroreduction of ClCH 2 CN. The lower overpotential that implies lesser energy consumption for the electroreduction and the green features of [BMIM][BF 4 ] jointly support the use of imidazolium-based RTILs for eco-green electrodetoxification of halohydrocarbons like Chloroacetonitrile.
P.-l. Fabre - One of the best experts on this subject based on the ideXlab platform.
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Electrocatalytic carboxylation of Chloroacetonitrile mediated by a Co(I) phenanthroline complex: Mechanistic and spectroscopic studies
Journal of Electroanalytical Chemistry, 2013Co-Authors: P.-l. Fabre, Dancheng Chen, O. Reynes, Nadia Chouini-lalanne, Valérie SartorAbstract:Abstract Mechanisms implied in the electrocarboxylation of Chloroacetonitrile (Cl–CH 2 –CN, noted RCl) mediated by [Co(II)(phen) 3 ] 2+ have been investigated by cyclic voltammetry and spectroelectrochemistry (UV–Visible and e.p.r.). The studies showed that the oxidative addition of Chloroacetonitrile on the electrogenerated [Co(I)(phen) 2 ] + yields an alkyl-cobalt R-Co(III) complex. This complex can either be reduced into an alkyl-cobalt(II) or undergoes a homolytic cobalt–carbon bond cleavage to form the organic radical R and the [Co(II)(phen) 2 ] 2+ complex. Whatever the process, R − and [Co(I)(phen) 2 ] + were produced. In presence of free phenanthroline, the catalytic behaviour of the complex was strongly vanished because the formation of the active complex [Co(I)(phen) 2 ] + is restricted. Under CO 2 atmosphere, the catalytic electrocarboxylation of Chloroacetonitrile was observed. Bulk electrolyses showed that the carboxylated and faradic yields depended on the applied electrolysis potential and free phenanthroline concentration.
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Electrocarboxylation of Chloroacetonitrile by a Cobalt(I) complex of terpyridine
Electrochimica Acta, 2011Co-Authors: Dancheng Chen, P.-l. Fabre, O. ReynesAbstract:The electrocarboxylation of Chloroacetonitrile (NC–CH2–ClRCl) mediated by [CoIIL2]2+ (L = terpyridine) was investigated by cyclic voltammetry. Electrochemical studies under argon atmosphere showed that the monoelectronic reduction of [CoIIL2]2+ yielded a Cobalt(I) complex which after the loss of a terpyridine ligand reacted with Chloroacetonitrile. The oxidative addition of Chloroacetonitrile on [CoIL]+ gave an alkylCobalt(III) complex [R–CoIIIL]2+ which was reduced into an alkylCobalt(II) complex, highly unstable and decomposed into an alkyl anion and a Cobalt(II) complex. Under carbon dioxide atmosphere, Cobalt(I) complex was shown to be unreactive towards CO2 but CO2 insertion was observed in the alkylCobalt(III) complex [R–CoIIIL] 2+ giving probably a CO2 adduct [R–CoIIIL(CO2)]2+. This adduct presented a strong adsorption at the carbon electrode and was reduced at potential less cathodic than the one of alkylCobalt(III) complex. After reduction, the carboxylate RCO2− (NC–CH2–CO2−) was released and a catalytic bielectronic carboxylation of Chloroacetonitrile took place. Controlled potential electrolyses confirmed the catalytic process and gave for cyanoacetic acid faradic yields up to 60% under low overpotential conditions.
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Electrocarboxylation of Chloroacetonitrile mediated by electrogenerated cobalt(I) phenanthroline
Elsevier, 2010Co-Authors: P.-l. Fabre, O. ReynesAbstract:The electrocarboxylation of Chloroacetonitrile mediated by [Co(II)(phen)3]2+ has been investigated. Cyclic voltammetry studies of [Co(II)(phen)3]2+ have shown that [Co(I)(phen)3]+, an 18 electron complex, activates Chloroacetonitrile by an oxidative addition through the loss of a phenanthroline ligand to give [RCo(III)(phen)2Cl]+. The unstable one-electron-reduced complex underwent Co–C bond cleavage. In carbon dioxide saturated solution, CO2 insertion proceeds after reduction of the alkylcobalt complex. A catalytic current is observed which corresponds to the electrocarboxylation of Chloroacetonitrile into cyanoacetic acid. Electrolyses confirmed the process and gave faradic yield of 62% in cyanoacetic acid at potentials that are about 0.3 V less cathodic than the one required for Ni(salen). Keywords: Electrocarboxylation, Cobalt tris (phenanthroline), Electrocatalysis, Chloroacetonitrile, Cyanoacetic aci
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Electrocarboxylation of Chloroacetonitrile mediated by electrogenerated cobalt(I) phenanthroline
Electrochemistry Communications, 2010Co-Authors: P.-l. Fabre, O. ReynesAbstract:Abstract The electrocarboxylation of Chloroacetonitrile mediated by [Co(II)(phen)3]2+ has been investigated. Cyclic voltammetry studies of [Co(II)(phen)3]2+ have shown that [Co(I)(phen)3]+, an 18 electron complex, activates Chloroacetonitrile by an oxidative addition through the loss of a phenanthroline ligand to give [RCo(III)(phen)2Cl]+. The unstable one-electron-reduced complex underwent Co–C bond cleavage. In carbon dioxide saturated solution, CO2 insertion proceeds after reduction of the alkylcobalt complex. A catalytic current is observed which corresponds to the electrocarboxylation of Chloroacetonitrile into cyanoacetic acid. Electrolyses confirmed the process and gave faradic yield of 62% in cyanoacetic acid at potentials that are about 0.3 V less cathodic than the one required for Ni(salen).
Christian Bruneau - One of the best experts on this subject based on the ideXlab platform.
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Imidazolium-oxazoline salts in ruthenium catalysed allylic substitution and cross metathesis of formed branched isomers
European Journal of Inorganic Chemistry, 2010Co-Authors: H. Ben Ammar, B. Ben Hassine, Cédric Fischmeister, Pierre H. Dixneuf, Christian BruneauAbstract:Imidazolium-oxazoline chlorides have been prepared from Chloroacetonitrile and used to generate bidentate mixed NHC-oxazoline ligands for ruthenium-catalyzed substitution of cinnamyl chloride by phenols. These ligands associated to [RuCp*(MeCN)3][PF6] promote allylic substitution reactions at room temperature with high regioselectivity in favour of the branched isomers giving terminal alkenes. These allylic ethers have been involved in further ruthenium-catalyzed cross metathesis reactions with electron-deficient olefins to give unsaturated esters and aldehydes.