2010
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Electrochemical bromination of peracetylated d-glucal: Effect of DMSO on chemoselectivity Article de journal I Damljanović; M Vukićević; D Manojlović; N Sojic; O Buriez; R D Vukićević Electrochimica Acta, 55 (3), p. 965–969, 2010. @article{Damljanovic:2010,
title = {Electrochemical bromination of peracetylated d-glucal: Effect of DMSO on chemoselectivity},
author = {I Damljanovi\'{c} and M Vuki\'{c}evi\'{c} and D Manojlovi\'{c} and N Sojic and O Buriez and R D Vuki\'{c}evi\'{c}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-70849109027&doi=10.1016%2fj.electacta.2009.09.057&partnerID=40&md5=d753bdeed3ddcaff44a42c2a332df812},
doi = {10.1016/j.electacta.2009.09.057},
year = {2010},
date = {2010-01-01},
journal = {Electrochimica Acta},
volume = {55},
number = {3},
pages = {965--969},
abstract = {The electrochemical bromination of 3,4,6-tri-O-acetyl-d-glucal (1) has been investigated in dimethyl sulfoxide (DMSO) by cyclic voltammetry and preparative-scale electrolyses. In this solvent, the bromination involves a bromine-DMSO complex of the type [DMSO-Br]+Br- whose reactivity towards 1 was clearly evidenced by cyclic voltammetry. Importantly, only the monobrominated glucose and mannose derivatives were obtained from electrolyses. This specific behavior was attributed to the nucleophilicity of DMSO that may react with the oxocarbenium intermediate preventing thus a possible second bromination of the transient species. The gluco/manno ratio, roughly equal to 30/70, indicated an electrophilic attack by [DMSO-Br]+Br- preferentially from the β side of the starting glycal for steric reasons. The treatment of the crude product obtained after the end of the electrolyses with acetic anhydride allowed the preparation of derivatives in which the anomeric carbon bears an acetoxy group. Based on both the cyclic voltammetry experiments and preparative-scale electrolyses, a mechanism is proposed for the bromination of peracetylated d-glucal in DMSO. These new and original results are of high interest in carbohydrate chemistry and especially for the preparation of new valuable oligosaccharides. © 2009 Elsevier Ltd. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The electrochemical bromination of 3,4,6-tri-O-acetyl-d-glucal (1) has been investigated in dimethyl sulfoxide (DMSO) by cyclic voltammetry and preparative-scale electrolyses. In this solvent, the bromination involves a bromine-DMSO complex of the type [DMSO-Br]+Br- whose reactivity towards 1 was clearly evidenced by cyclic voltammetry. Importantly, only the monobrominated glucose and mannose derivatives were obtained from electrolyses. This specific behavior was attributed to the nucleophilicity of DMSO that may react with the oxocarbenium intermediate preventing thus a possible second bromination of the transient species. The gluco/manno ratio, roughly equal to 30/70, indicated an electrophilic attack by [DMSO-Br]+Br- preferentially from the β side of the starting glycal for steric reasons. The treatment of the crude product obtained after the end of the electrolyses with acetic anhydride allowed the preparation of derivatives in which the anomeric carbon bears an acetoxy group. Based on both the cyclic voltammetry experiments and preparative-scale electrolyses, a mechanism is proposed for the bromination of peracetylated d-glucal in DMSO. These new and original results are of high interest in carbohydrate chemistry and especially for the preparation of new valuable oligosaccharides. © 2009 Elsevier Ltd. All rights reserved. |
Synthesis and electrochemical study of an original copper(II)-capped salen-cyclodextrin complex Article de journal E Deunf; E Zaborova; S Guieu; Y Blériot; J -N Verpeaux; O Buriez; M Sollogoub; C Amatore European Journal of Inorganic Chemistry, (29), p. 4720–4727, 2010. @article{Deunf:2010,
title = {Synthesis and electrochemical study of an original copper(II)-capped salen-cyclodextrin complex},
author = {E Deunf and E Zaborova and S Guieu and Y Bl\'{e}riot and J -N Verpeaux and O Buriez and M Sollogoub and C Amatore},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78349284824&doi=10.1002%2fejic.200901208&partnerID=40&md5=c49a97fb828e67d03424443181136cc8},
doi = {10.1002/ejic.200901208},
year = {2010},
date = {2010-01-01},
journal = {European Journal of Inorganic Chemistry},
number = {29},
pages = {4720--4727},
abstract = {A new metallocapped cyclodextrin (CD) was synthesized by the regioselective debenzylation, induced by diisobutylaluminium hydride (DIBAL-H), of perbenzylated cyclodextrins. This reaction allowed for the efficient preparation of an unprecedented CD-salen type copper(II) complex. The electrochemical behavior of both the bound and unbound CD-salen compounds was investigated by cyclic voltammetry. Notably, it was shown that the presence of tert-butyl groups at the ortho- and para-positions of the salen aromatic rings stabilized the copper(II) phenoxyl radical species that was generated upon the one-electron oxidation of the starting compound. Importantly, this stabilization remained effective when the salen-type ligand was covalently attached to the CD. This allowed for investigations of the reactivity of the copper(II) phenoxyl radical complex towards a primary alcohol to be performed by cyclic voltammetry. This reaction can be considered as mimicking the behavior of galactose oxidase. However, under these conditions, no reactivity was observed in the presence of benzyl alcohol. This may be due to distortion, either of the initially square planar salen ligand after its grafting to the CD primary face, and/or of the CD itself. On the other hand, the electrochemical reduction of the un-grafted copper(II) salen-type ligand led to a transient anionic species that exhibited significant stability on the time-scale of the slow cyclic voltammetry measurement in the absence of the CD, but was unstable in the presence of the CD. In the latter case, it was demonstrated that the anionic species was protonated by the CD. Importantly, this protonation was not fast enough to prevent catalytic activation of iodomethane by the electro-generated copper(I)-capped salen CD complex. A new metallocapped cyclodextrin was synthesized by a regioselective debenzylation reaction that was induced by diisobutylaluminium hydride (DIBAL-H). The electrochemical investigation of this original complex demonstrated that grafting of a copper salen-type complex to a cyclodextrin leads to changes in the reactivity of the intermediary species. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A new metallocapped cyclodextrin (CD) was synthesized by the regioselective debenzylation, induced by diisobutylaluminium hydride (DIBAL-H), of perbenzylated cyclodextrins. This reaction allowed for the efficient preparation of an unprecedented CD-salen type copper(II) complex. The electrochemical behavior of both the bound and unbound CD-salen compounds was investigated by cyclic voltammetry. Notably, it was shown that the presence of tert-butyl groups at the ortho- and para-positions of the salen aromatic rings stabilized the copper(II) phenoxyl radical species that was generated upon the one-electron oxidation of the starting compound. Importantly, this stabilization remained effective when the salen-type ligand was covalently attached to the CD. This allowed for investigations of the reactivity of the copper(II) phenoxyl radical complex towards a primary alcohol to be performed by cyclic voltammetry. This reaction can be considered as mimicking the behavior of galactose oxidase. However, under these conditions, no reactivity was observed in the presence of benzyl alcohol. This may be due to distortion, either of the initially square planar salen ligand after its grafting to the CD primary face, and/or of the CD itself. On the other hand, the electrochemical reduction of the un-grafted copper(II) salen-type ligand led to a transient anionic species that exhibited significant stability on the time-scale of the slow cyclic voltammetry measurement in the absence of the CD, but was unstable in the presence of the CD. In the latter case, it was demonstrated that the anionic species was protonated by the CD. Importantly, this protonation was not fast enough to prevent catalytic activation of iodomethane by the electro-generated copper(I)-capped salen CD complex. A new metallocapped cyclodextrin was synthesized by a regioselective debenzylation reaction that was induced by diisobutylaluminium hydride (DIBAL-H). The electrochemical investigation of this original complex demonstrated that grafting of a copper salen-type complex to a cyclodextrin leads to changes in the reactivity of the intermediary species. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
2009
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Electrochemical behavior of nanoelectrode ensembles in the ionic liquid [BMIm][BF4] Article de journal M De Leo; L M Moretto; O Buriez; P Ugo Electroanalysis, 21 (3-5), p. 392–398, 2009. @article{DeLeo:2009,
title = {Electrochemical behavior of nanoelectrode ensembles in the ionic liquid [BMIm][BF4]},
author = {M De Leo and L M Moretto and O Buriez and P Ugo},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-60549112441&doi=10.1002%2felan.200804414&partnerID=40&md5=632103a63314de43db5fbad40963633e},
doi = {10.1002/elan.200804414},
year = {2009},
date = {2009-01-01},
journal = {Electroanalysis},
volume = {21},
number = {3-5},
pages = {392--398},
abstract = {The electrochemical behavior of nanoelectrode ensembles (NEEs), prepared by electroless plating of Au using microporous polycarbonate membranes as template, is tested in the ionic liquid [BMIm][BF4]. The accessible potential window is significantly wider in [BMIm][BF4] than in water, extending approximately, for 3.4 V vs. 1 V, respectively. The voltammetric behavior at NEEs of two redox probes, namely butyl viologen (BV2+) and (ferrocenylmethyl) trimethylammonium (FA+) are examined at different scan rates. In both cases, at scan rates higher than 200 mV/s sigmoidally shaped voltammograms typical of a pure radial diffusion regime are observed. At lower scan rates the voltammograms are peak shaped, as expected for total overlap diffusion conditions. This is the first time that the pure radial regime is obtained with NEEs made using commercially available polycarbonate templates, since in water solution only the total overlap regime is typically observed. This is explained as a consequence of the high viscosity of [BMIm][BF4] which reflects in lowering of diffusion coefficients and smaller thickness of diffusion layers, for the same time scale, with respect to water solutions, but also the fact that the nanoelectrodes are slightly recessed helps in observing the pure radial regime. In order to make operative the pure radial condition it is indeed required that the thickness of diffusion layer at individual nanoelectrodes be smaller than the hemi-distance between neighboring nanoelectrodes. Examining the analytical performances achievable with NEEs in [BMIm][BF4], it is shown that a limit is given by the decreased diffusion coefficients. Detection limits at NEEs in the ionic liquid are indeed higher than those obtained in water solutions. This notwithstanding, detections limits at NEEs in [BMIm][BF4] are always improved with respect to those at conventional electrodes. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The electrochemical behavior of nanoelectrode ensembles (NEEs), prepared by electroless plating of Au using microporous polycarbonate membranes as template, is tested in the ionic liquid [BMIm][BF4]. The accessible potential window is significantly wider in [BMIm][BF4] than in water, extending approximately, for 3.4 V vs. 1 V, respectively. The voltammetric behavior at NEEs of two redox probes, namely butyl viologen (BV2+) and (ferrocenylmethyl) trimethylammonium (FA+) are examined at different scan rates. In both cases, at scan rates higher than 200 mV/s sigmoidally shaped voltammograms typical of a pure radial diffusion regime are observed. At lower scan rates the voltammograms are peak shaped, as expected for total overlap diffusion conditions. This is the first time that the pure radial regime is obtained with NEEs made using commercially available polycarbonate templates, since in water solution only the total overlap regime is typically observed. This is explained as a consequence of the high viscosity of [BMIm][BF4] which reflects in lowering of diffusion coefficients and smaller thickness of diffusion layers, for the same time scale, with respect to water solutions, but also the fact that the nanoelectrodes are slightly recessed helps in observing the pure radial regime. In order to make operative the pure radial condition it is indeed required that the thickness of diffusion layer at individual nanoelectrodes be smaller than the hemi-distance between neighboring nanoelectrodes. Examining the analytical performances achievable with NEEs in [BMIm][BF4], it is shown that a limit is given by the decreased diffusion coefficients. Detection limits at NEEs in the ionic liquid are indeed higher than those obtained in water solutions. This notwithstanding, detections limits at NEEs in [BMIm][BF4] are always improved with respect to those at conventional electrodes. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. |
2007
|
Electrochemical activation of β-lapachone in β-cyclodextrin inclusion complexes and reactivity of its reduced form towards oxygen in aqueous solutions Article de journal F C de Abreu; D C M Ferreira; M O F Goulart; O Buriez; C Amatore Journal of Electroanalytical Chemistry, 608 (2), p. 125–132, 2007. @article{deAbreu:2007,
title = {Electrochemical activation of β-lapachone in β-cyclodextrin inclusion complexes and reactivity of its reduced form towards oxygen in aqueous solutions},
author = {F C de Abreu and D C M Ferreira and M O F Goulart and O Buriez and C Amatore},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548644479&doi=10.1016%2fj.jelechem.2007.05.020&partnerID=40&md5=8ed62bd89e5795ebf0a17117cd46d1dc},
doi = {10.1016/j.jelechem.2007.05.020},
year = {2007},
date = {2007-01-01},
journal = {Journal of Electroanalytical Chemistry},
volume = {608},
number = {2},
pages = {125--132},
abstract = {β-Lapachone (1) is a natural ortho-naphthoquinone that has been shown to have a variety of pharmacological effects, mainly anticancer activity. As a single agent, β-lapachone has demonstrated significant antineoplastic activity against several human cancer cell lines at concentrations typically in the range of 1-10 μM (IC50). The use of cyclodextrins is useful to overcome solubility and bioavailability problems. In the present case, cyclic voltammetry and UV/vis spectroscopy have been used to monitor the inclusion phenomena of β-lapachone within the cavity of β-cyclodextrin, together with studies concerning the competitive effects of ethanol concentration on this behavior. A value of 15 ± 5 M-1 was found for the association constant between β-lapachone and β-cyclodextrin in phosphate buffer, in the presence of 5% ethanol. The electrochemical behavior of the β-lapachone reduced form suggests external interactions between the hydroquinone and β-cyclodextrin via the formation of hydrogen bonds. Electrochemical studies were also performed in the presence of oxygen, since the redox environment of β-lapachone biological targets is considered very important for its therapeutical efficiency. In the presence of O2, β-lapachone has shown a catalytic reduction wave, related probably to an electron transfer to oxygen, generating oxygen reactive species and giving back the parent quinone, leading thus to a redox cycle, with a kinetic apparent constant of 40 s-1. These in vitro results correlate with in vivo activities. © 2007 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
β-Lapachone (1) is a natural ortho-naphthoquinone that has been shown to have a variety of pharmacological effects, mainly anticancer activity. As a single agent, β-lapachone has demonstrated significant antineoplastic activity against several human cancer cell lines at concentrations typically in the range of 1-10 μM (IC50). The use of cyclodextrins is useful to overcome solubility and bioavailability problems. In the present case, cyclic voltammetry and UV/vis spectroscopy have been used to monitor the inclusion phenomena of β-lapachone within the cavity of β-cyclodextrin, together with studies concerning the competitive effects of ethanol concentration on this behavior. A value of 15 ± 5 M-1 was found for the association constant between β-lapachone and β-cyclodextrin in phosphate buffer, in the presence of 5% ethanol. The electrochemical behavior of the β-lapachone reduced form suggests external interactions between the hydroquinone and β-cyclodextrin via the formation of hydrogen bonds. Electrochemical studies were also performed in the presence of oxygen, since the redox environment of β-lapachone biological targets is considered very important for its therapeutical efficiency. In the presence of O2, β-lapachone has shown a catalytic reduction wave, related probably to an electron transfer to oxygen, generating oxygen reactive species and giving back the parent quinone, leading thus to a redox cycle, with a kinetic apparent constant of 40 s-1. These in vitro results correlate with in vivo activities. © 2007 Elsevier B.V. All rights reserved. |
Electrochemical aerobic oxidation of aminocyclopropanes to endoperoxides Article de journal C Madelaine; Y Six; O Buriez Angewandte Chemie - International Edition, 46 (42), p. 8046–8049, 2007. @article{Madelaine:2007,
title = {Electrochemical aerobic oxidation of aminocyclopropanes to endoperoxides},
author = {C Madelaine and Y Six and O Buriez},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-35649020765&doi=10.1002%2fanie.200702903&partnerID=40&md5=3fcf75ce883463516bde923eb9437745},
doi = {10.1002/anie.200702903},
year = {2007},
date = {2007-01-01},
journal = {Angewandte Chemie - International Edition},
volume = {46},
number = {42},
pages = {8046--8049},
abstract = {(Chemical Equation Presented) Electrical synthesizer: Results of cyclic voltammetric studies on a range of aminocyclopropanes in the absence or in the presence of oxygen are in full agreement with the currently accepted autocatalytic mechanism for the aerobic oxidation of these compounds. A simple and efficient procedure was developed for the electrosynthesis of the corresponding endoperoxides (see scheme), some of which exhibit moderate antimalarial activity. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
(Chemical Equation Presented) Electrical synthesizer: Results of cyclic voltammetric studies on a range of aminocyclopropanes in the absence or in the presence of oxygen are in full agreement with the currently accepted autocatalytic mechanism for the aerobic oxidation of these compounds. A simple and efficient procedure was developed for the electrosynthesis of the corresponding endoperoxides (see scheme), some of which exhibit moderate antimalarial activity. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA. |
2005
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Co-I and Co-0-bipyridine complexes obtained by reduction of CoBr(2)bpy: Electrochemical behaviour and investigation of their reactions with aromatic halides and vinylic acetates Article de journal L Polleux; E Labbe; O Buriez; J Perichon Chemistry-a European Journal, 11 (16), p. 4678-4686, 2005. @article{RID:0721150706479-4,
title = {Co-I and Co-0-bipyridine complexes obtained by reduction of CoBr(2)bpy: Electrochemical behaviour and investigation of their reactions with aromatic halides and vinylic acetates},
author = {L Polleux and E Labbe and O Buriez and J Perichon},
year = {2005},
date = {2005-01-01},
journal = {Chemistry-a European Journal},
volume = {11},
number = {16},
pages = {4678-4686},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
On the reactivity of the electrogenerated cobalt(I) species towards aryl halides in the presence of allylethers Article de journal K Kecili; O Buriez; E Labbe; J Perichon Electrochimica Acta, 50 (12), p. 2377-2384, 2005. @article{RID:0721150706480-9,
title = {On the reactivity of the electrogenerated cobalt(I) species towards aryl halides in the presence of allylethers},
author = {K Kecili and O Buriez and E Labbe and J Perichon},
year = {2005},
date = {2005-01-01},
journal = {Electrochimica Acta},
volume = {50},
number = {12},
pages = {2377-2384},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
2004
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Mechanism(s) of the cobalt-catalyzed electrochemical coupling between aromatic halides and allylic acetates Article de journal P Gomes; O Buriez; E Labbe; C Gosmini; J Perichon Journal of Electroanalytical Chemistry, 562 (2), p. 255-260, 2004. @article{RID:0721150706480-12,
title = {Mechanism(s) of the cobalt-catalyzed electrochemical coupling between aromatic halides and allylic acetates},
author = {P Gomes and O Buriez and E Labbe and C Gosmini and J Perichon},
year = {2004},
date = {2004-01-01},
journal = {Journal of Electroanalytical Chemistry},
volume = {562},
number = {2},
pages = {255-260},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
2003
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Electroanalytical investigation of the cobalt-catalyzed electrochemical dimerization of allylic acetates. Role played by iron(II) ions Article de journal O Buriez; E Labbe; J Perichon Journal of Electroanalytical Chemistry, 543 (2), p. 143-151, 2003. @article{RID:0721150706480-19,
title = {Electroanalytical investigation of the cobalt-catalyzed electrochemical dimerization of allylic acetates. Role played by iron(II) ions},
author = {O Buriez and E Labbe and J Perichon},
year = {2003},
date = {2003-01-01},
journal = {Journal of Electroanalytical Chemistry},
volume = {543},
number = {2},
pages = {143-151},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
