The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Sylvain Juge - One of the best experts on this subject based on the ideXlab platform.
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Designing Silylated l -Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and 18 F-Labelling
European Journal of Organic Chemistry, 2017Co-Authors: Baptiste Rugeri, Hassib Audi, Raluca Malacea-kabbara, Pawel Jewula, Radouane Koudih, Delphine Vimont, Jürgen Schulz, Philippe Fernandez, Sylvain JugeAbstract:An efficient semisynthesis of silylated l-amino acids by reaction of silylated benzaldehydes with a phosphonium l-amino acid used as a Wittig Reagent is described. The efficiency of the silylated l-amino acids in peptide synthesis was investigated by coupling both the carboxylic acid and the amino moiety with l-alanine and phenylalanine derivatives, respectively. The silylated derivatives were treated with KF or tetrabutylammonium fluoride to give the corresponding fluorosilyl derivatives without racemization. The hydrolysis of the fluorosilylated derivatives in phosphate buffer at pH 7.2 was checked. Finally, the 18F-labelling of di-tert-butylsilylated saturated and unsaturated dipeptides was achieved in hot DMSO with a mixture of K[18F]/cryptand (K2.2.2) and acetic acid. The 18F-labelled dipeptides were obtained with radiochemical yields and molar activities of up to 31 % and 410 GBq/µmol, respectively. Consequently, this semisynthesis involving a Wittig reaction offers a new and efficient route for the design and 18F-labelling of Si-based amino acids and peptide derivatives, which may find applications in PET imaging.
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Designing Silylated l‐Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and 18F‐Labelling
European Journal of Organic Chemistry, 2017Co-Authors: Baptiste Rugeri, Hassib Audi, Raluca Malacea-kabbara, Pawel Jewula, Radouane Koudih, Delphine Vimont, Jürgen Schulz, Philippe Fernandez, Sylvain JugeAbstract:An efficient semisynthesis of silylated l-amino acids by reaction of silylated benzaldehydes with a phosphonium l-amino acid used as a Wittig Reagent is described. The efficiency of the silylated l-amino acids in peptide synthesis was investigated by coupling both the carboxylic acid and the amino moiety with l-alanine and phenylalanine derivatives, respectively. The silylated derivatives were treated with KF or tetrabutylammonium fluoride to give the corresponding fluorosilyl derivatives without racemization. The hydrolysis of the fluorosilylated derivatives in phosphate buffer at pH 7.2 was checked. Finally, the 18F-labelling of di-tert-butylsilylated saturated and unsaturated dipeptides was achieved in hot DMSO with a mixture of K[18F]/cryptand (K2.2.2) and acetic acid. The 18F-labelled dipeptides were obtained with radiochemical yields and molar activities of up to 31 % and 410 GBq/µmol, respectively. Consequently, this semisynthesis involving a Wittig reaction offers a new and efficient route for the design and 18F-labelling of Si-based amino acids and peptide derivatives, which may find applications in PET imaging.
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Modular Hemisyntheses of Boronato‐ and Trifluoroborato‐Substituted L‐NHBoc Amino Acid and Peptide Derivatives.
ChemInform, 2014Co-Authors: Hassib Audi, Emmanuelle Rémond, Marie-joëlle Eymin, Arnaud Tessier, Raluca Malacea-kabbara, Sylvain JugeAbstract:Modular hemisyntheses of boronato- and trifluoroborato-substituted amino acid derivatives are achieved based on the reaction of Wittig Reagent (I) with aldehydes followed by Ir-catalyzed boronation.
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Modular Hemisyntheses of Boronato‐ and Trifluoroborato‐Substituted L‐NHBoc Amino Acid and Peptide Derivatives
European Journal of Organic Chemistry, 2013Co-Authors: Hassib Audi, Emmanuelle Rémond, Marie-joëlle Eymin, Arnaud Tessier, Raluca Malacea-kabbara, Sylvain JugeAbstract:Modular hemisyntheses of boronato- and trifluoroborato-substituted amino acid and peptide derivatives by using Wittig and C–H iridium-catalyzed borylation as key reactions, are described. Amino ester precursors bearing an aromatic moiety on a lateral chain were prepared by reaction of a new L-NHBoc-amino acid Wittig Reagent with the corresponding aromatic aldehydes. After esterification and hydrogenation, the borylation of amino esters was achieved with yields up to 82 % by using the catalysed reaction of bis(pinacolato) diborane Reagent (B2Pin2) in the presence of an iridium complex. Interestingly, this iridium-catalyzed borylation was also performed with a dipeptide in 78 % yield. Finally, reaction of the boronato amino acids with KHF2 or NaI in the presence of chloramine led to the corresponding trifluoroborato or iodo derivatives in good to excellent yields. A study of the hydrolysis of the trifluoroborates in buffer solution by using 19F NMR monitoring, showed an excellent stability for the 3-methylthien-2-yl amino acid derivative. Consequently, this hemisynthesis offers an efficient route for the modular preparation of boron amino acid derivatives that are useful for the synthesis of modified peptides and the fluoride labelling of peptides.
Hassib Audi - One of the best experts on this subject based on the ideXlab platform.
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Designing Silylated l -Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and 18 F-Labelling
European Journal of Organic Chemistry, 2017Co-Authors: Baptiste Rugeri, Hassib Audi, Raluca Malacea-kabbara, Pawel Jewula, Radouane Koudih, Delphine Vimont, Jürgen Schulz, Philippe Fernandez, Sylvain JugeAbstract:An efficient semisynthesis of silylated l-amino acids by reaction of silylated benzaldehydes with a phosphonium l-amino acid used as a Wittig Reagent is described. The efficiency of the silylated l-amino acids in peptide synthesis was investigated by coupling both the carboxylic acid and the amino moiety with l-alanine and phenylalanine derivatives, respectively. The silylated derivatives were treated with KF or tetrabutylammonium fluoride to give the corresponding fluorosilyl derivatives without racemization. The hydrolysis of the fluorosilylated derivatives in phosphate buffer at pH 7.2 was checked. Finally, the 18F-labelling of di-tert-butylsilylated saturated and unsaturated dipeptides was achieved in hot DMSO with a mixture of K[18F]/cryptand (K2.2.2) and acetic acid. The 18F-labelled dipeptides were obtained with radiochemical yields and molar activities of up to 31 % and 410 GBq/µmol, respectively. Consequently, this semisynthesis involving a Wittig reaction offers a new and efficient route for the design and 18F-labelling of Si-based amino acids and peptide derivatives, which may find applications in PET imaging.
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Designing Silylated l‐Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and 18F‐Labelling
European Journal of Organic Chemistry, 2017Co-Authors: Baptiste Rugeri, Hassib Audi, Raluca Malacea-kabbara, Pawel Jewula, Radouane Koudih, Delphine Vimont, Jürgen Schulz, Philippe Fernandez, Sylvain JugeAbstract:An efficient semisynthesis of silylated l-amino acids by reaction of silylated benzaldehydes with a phosphonium l-amino acid used as a Wittig Reagent is described. The efficiency of the silylated l-amino acids in peptide synthesis was investigated by coupling both the carboxylic acid and the amino moiety with l-alanine and phenylalanine derivatives, respectively. The silylated derivatives were treated with KF or tetrabutylammonium fluoride to give the corresponding fluorosilyl derivatives without racemization. The hydrolysis of the fluorosilylated derivatives in phosphate buffer at pH 7.2 was checked. Finally, the 18F-labelling of di-tert-butylsilylated saturated and unsaturated dipeptides was achieved in hot DMSO with a mixture of K[18F]/cryptand (K2.2.2) and acetic acid. The 18F-labelled dipeptides were obtained with radiochemical yields and molar activities of up to 31 % and 410 GBq/µmol, respectively. Consequently, this semisynthesis involving a Wittig reaction offers a new and efficient route for the design and 18F-labelling of Si-based amino acids and peptide derivatives, which may find applications in PET imaging.
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Modular Hemisyntheses of Boronato‐ and Trifluoroborato‐Substituted L‐NHBoc Amino Acid and Peptide Derivatives.
ChemInform, 2014Co-Authors: Hassib Audi, Emmanuelle Rémond, Marie-joëlle Eymin, Arnaud Tessier, Raluca Malacea-kabbara, Sylvain JugeAbstract:Modular hemisyntheses of boronato- and trifluoroborato-substituted amino acid derivatives are achieved based on the reaction of Wittig Reagent (I) with aldehydes followed by Ir-catalyzed boronation.
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Modular Hemisyntheses of Boronato‐ and Trifluoroborato‐Substituted L‐NHBoc Amino Acid and Peptide Derivatives
European Journal of Organic Chemistry, 2013Co-Authors: Hassib Audi, Emmanuelle Rémond, Marie-joëlle Eymin, Arnaud Tessier, Raluca Malacea-kabbara, Sylvain JugeAbstract:Modular hemisyntheses of boronato- and trifluoroborato-substituted amino acid and peptide derivatives by using Wittig and C–H iridium-catalyzed borylation as key reactions, are described. Amino ester precursors bearing an aromatic moiety on a lateral chain were prepared by reaction of a new L-NHBoc-amino acid Wittig Reagent with the corresponding aromatic aldehydes. After esterification and hydrogenation, the borylation of amino esters was achieved with yields up to 82 % by using the catalysed reaction of bis(pinacolato) diborane Reagent (B2Pin2) in the presence of an iridium complex. Interestingly, this iridium-catalyzed borylation was also performed with a dipeptide in 78 % yield. Finally, reaction of the boronato amino acids with KHF2 or NaI in the presence of chloramine led to the corresponding trifluoroborato or iodo derivatives in good to excellent yields. A study of the hydrolysis of the trifluoroborates in buffer solution by using 19F NMR monitoring, showed an excellent stability for the 3-methylthien-2-yl amino acid derivative. Consequently, this hemisynthesis offers an efficient route for the modular preparation of boron amino acid derivatives that are useful for the synthesis of modified peptides and the fluoride labelling of peptides.
Raluca Malacea-kabbara - One of the best experts on this subject based on the ideXlab platform.
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Designing Silylated l -Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and 18 F-Labelling
European Journal of Organic Chemistry, 2017Co-Authors: Baptiste Rugeri, Hassib Audi, Raluca Malacea-kabbara, Pawel Jewula, Radouane Koudih, Delphine Vimont, Jürgen Schulz, Philippe Fernandez, Sylvain JugeAbstract:An efficient semisynthesis of silylated l-amino acids by reaction of silylated benzaldehydes with a phosphonium l-amino acid used as a Wittig Reagent is described. The efficiency of the silylated l-amino acids in peptide synthesis was investigated by coupling both the carboxylic acid and the amino moiety with l-alanine and phenylalanine derivatives, respectively. The silylated derivatives were treated with KF or tetrabutylammonium fluoride to give the corresponding fluorosilyl derivatives without racemization. The hydrolysis of the fluorosilylated derivatives in phosphate buffer at pH 7.2 was checked. Finally, the 18F-labelling of di-tert-butylsilylated saturated and unsaturated dipeptides was achieved in hot DMSO with a mixture of K[18F]/cryptand (K2.2.2) and acetic acid. The 18F-labelled dipeptides were obtained with radiochemical yields and molar activities of up to 31 % and 410 GBq/µmol, respectively. Consequently, this semisynthesis involving a Wittig reaction offers a new and efficient route for the design and 18F-labelling of Si-based amino acids and peptide derivatives, which may find applications in PET imaging.
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Designing Silylated l‐Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and 18F‐Labelling
European Journal of Organic Chemistry, 2017Co-Authors: Baptiste Rugeri, Hassib Audi, Raluca Malacea-kabbara, Pawel Jewula, Radouane Koudih, Delphine Vimont, Jürgen Schulz, Philippe Fernandez, Sylvain JugeAbstract:An efficient semisynthesis of silylated l-amino acids by reaction of silylated benzaldehydes with a phosphonium l-amino acid used as a Wittig Reagent is described. The efficiency of the silylated l-amino acids in peptide synthesis was investigated by coupling both the carboxylic acid and the amino moiety with l-alanine and phenylalanine derivatives, respectively. The silylated derivatives were treated with KF or tetrabutylammonium fluoride to give the corresponding fluorosilyl derivatives without racemization. The hydrolysis of the fluorosilylated derivatives in phosphate buffer at pH 7.2 was checked. Finally, the 18F-labelling of di-tert-butylsilylated saturated and unsaturated dipeptides was achieved in hot DMSO with a mixture of K[18F]/cryptand (K2.2.2) and acetic acid. The 18F-labelled dipeptides were obtained with radiochemical yields and molar activities of up to 31 % and 410 GBq/µmol, respectively. Consequently, this semisynthesis involving a Wittig reaction offers a new and efficient route for the design and 18F-labelling of Si-based amino acids and peptide derivatives, which may find applications in PET imaging.
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Modular Hemisyntheses of Boronato‐ and Trifluoroborato‐Substituted L‐NHBoc Amino Acid and Peptide Derivatives.
ChemInform, 2014Co-Authors: Hassib Audi, Emmanuelle Rémond, Marie-joëlle Eymin, Arnaud Tessier, Raluca Malacea-kabbara, Sylvain JugeAbstract:Modular hemisyntheses of boronato- and trifluoroborato-substituted amino acid derivatives are achieved based on the reaction of Wittig Reagent (I) with aldehydes followed by Ir-catalyzed boronation.
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Modular Hemisyntheses of Boronato‐ and Trifluoroborato‐Substituted L‐NHBoc Amino Acid and Peptide Derivatives
European Journal of Organic Chemistry, 2013Co-Authors: Hassib Audi, Emmanuelle Rémond, Marie-joëlle Eymin, Arnaud Tessier, Raluca Malacea-kabbara, Sylvain JugeAbstract:Modular hemisyntheses of boronato- and trifluoroborato-substituted amino acid and peptide derivatives by using Wittig and C–H iridium-catalyzed borylation as key reactions, are described. Amino ester precursors bearing an aromatic moiety on a lateral chain were prepared by reaction of a new L-NHBoc-amino acid Wittig Reagent with the corresponding aromatic aldehydes. After esterification and hydrogenation, the borylation of amino esters was achieved with yields up to 82 % by using the catalysed reaction of bis(pinacolato) diborane Reagent (B2Pin2) in the presence of an iridium complex. Interestingly, this iridium-catalyzed borylation was also performed with a dipeptide in 78 % yield. Finally, reaction of the boronato amino acids with KHF2 or NaI in the presence of chloramine led to the corresponding trifluoroborato or iodo derivatives in good to excellent yields. A study of the hydrolysis of the trifluoroborates in buffer solution by using 19F NMR monitoring, showed an excellent stability for the 3-methylthien-2-yl amino acid derivative. Consequently, this hemisynthesis offers an efficient route for the modular preparation of boron amino acid derivatives that are useful for the synthesis of modified peptides and the fluoride labelling of peptides.
Baptiste Rugeri - One of the best experts on this subject based on the ideXlab platform.
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Designing Silylated l -Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and 18 F-Labelling
European Journal of Organic Chemistry, 2017Co-Authors: Baptiste Rugeri, Hassib Audi, Raluca Malacea-kabbara, Pawel Jewula, Radouane Koudih, Delphine Vimont, Jürgen Schulz, Philippe Fernandez, Sylvain JugeAbstract:An efficient semisynthesis of silylated l-amino acids by reaction of silylated benzaldehydes with a phosphonium l-amino acid used as a Wittig Reagent is described. The efficiency of the silylated l-amino acids in peptide synthesis was investigated by coupling both the carboxylic acid and the amino moiety with l-alanine and phenylalanine derivatives, respectively. The silylated derivatives were treated with KF or tetrabutylammonium fluoride to give the corresponding fluorosilyl derivatives without racemization. The hydrolysis of the fluorosilylated derivatives in phosphate buffer at pH 7.2 was checked. Finally, the 18F-labelling of di-tert-butylsilylated saturated and unsaturated dipeptides was achieved in hot DMSO with a mixture of K[18F]/cryptand (K2.2.2) and acetic acid. The 18F-labelled dipeptides were obtained with radiochemical yields and molar activities of up to 31 % and 410 GBq/µmol, respectively. Consequently, this semisynthesis involving a Wittig reaction offers a new and efficient route for the design and 18F-labelling of Si-based amino acids and peptide derivatives, which may find applications in PET imaging.
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Designing Silylated l‐Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and 18F‐Labelling
European Journal of Organic Chemistry, 2017Co-Authors: Baptiste Rugeri, Hassib Audi, Raluca Malacea-kabbara, Pawel Jewula, Radouane Koudih, Delphine Vimont, Jürgen Schulz, Philippe Fernandez, Sylvain JugeAbstract:An efficient semisynthesis of silylated l-amino acids by reaction of silylated benzaldehydes with a phosphonium l-amino acid used as a Wittig Reagent is described. The efficiency of the silylated l-amino acids in peptide synthesis was investigated by coupling both the carboxylic acid and the amino moiety with l-alanine and phenylalanine derivatives, respectively. The silylated derivatives were treated with KF or tetrabutylammonium fluoride to give the corresponding fluorosilyl derivatives without racemization. The hydrolysis of the fluorosilylated derivatives in phosphate buffer at pH 7.2 was checked. Finally, the 18F-labelling of di-tert-butylsilylated saturated and unsaturated dipeptides was achieved in hot DMSO with a mixture of K[18F]/cryptand (K2.2.2) and acetic acid. The 18F-labelled dipeptides were obtained with radiochemical yields and molar activities of up to 31 % and 410 GBq/µmol, respectively. Consequently, this semisynthesis involving a Wittig reaction offers a new and efficient route for the design and 18F-labelling of Si-based amino acids and peptide derivatives, which may find applications in PET imaging.
Tayebeh Momeni - One of the best experts on this subject based on the ideXlab platform.
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Recent applications of the Wittig reaction in alkaloid synthesis
The Alkaloids. Chemistry and biology, 2020Co-Authors: Majid M. Heravi, Vahideh Zadsirjan, Hoda Hamidi, Mansoureh Daraie, Tayebeh MomeniAbstract:The Wittig reaction is the chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide (the Wittig Reagent) to afford an alkene and triphenylphosphine oxide. Noteworthy, this reaction results in the synthesis of alkenes in a selective and predictable fashion. Thus, it became as one of the keystone of synthetic organic chemistry, especially in the total synthesis of natural products, where the selectivity of a reaction is paramount of importance. A literature survey disclosed the existence of vast numbers of related reports and comprehensive reviews on the applications of this important name reaction in the total synthesis of natural products. However, the aim of this chapter is to underscore, the applications of the Wittig reaction in the total synthesis of one the most important and prevalent classes of natural products, the alkaloids, especially those showing important and diverse biological activities.
