Author: Christophe Darcel

Modular P-Chirogenic Aminophosphane-Phosphinite Ligands for Rh-Catalyzed Asymmetric Hydrogenation: A New Model for Prediction of Enantioselectivity

2007

An original series of P-chirogenic aminophosphane-phosphinite (AMPP) ligands has been synthesized from (+)- or(–)-ephedrine in 23 to 61 % overall yields by a versatile three-step methodology. The AMPP ligands, bearing either one or two P-chirogenic centers, were used in the form of rhodium complexes for the catalyzed hydrogenation of α-acetamidocinnamate as a test reaction. Notably, even with AMPP ligands all derived from (+)-ephedrine, variation of the substituent on a P-center allowed the phenylalanine derivatives to be obtained in either (S) or (R) absolute configurations, with ee values ranging from 99 % (S) to 88 % (R). The asymmetric induction was analyzed with the aid of X-ray struct…

Steric effectsPhosphiniteStereochemistryLigandOrganic ChemistryAsymmetric hydrogenationCyclohexane conformationSubstituentchemistry.chemical_elementAsymmetric inductionRhodiumchemistry.chemical_compoundchemistryPhysical and Theoretical ChemistryEuropean Journal of Organic Chemistry

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Ferrocenyl glycopeptides as electrochemical probes to detect autoantibodies in multiple sclerosis patients' será

2008

Abstract Glycopeptide analogues of CSF114(Glc), modified at N-terminus with new ferrocenyl carboxylic acid and a new ferrocenyl-thiphosphino amino acid, were used to implement a new electrochemical biosensor for autoantibody detection in multiple sclerosis. The ferrocenyl moiety of these "electrochemical probes" did not affect autoantibody recognition both in SP-ELISA and in inhibition experiments. By electrochemical monitoring the interactions of the modified peptides Fc-CSF114(Glc) and 4-FcPhP(S)Abu-CSF114(Glc) with the autoantibodies, we demonstrated that autoantibodies could be detected with a sensitivity comparable to ELISA method. The new electrochemical probes can be proposed to char…

Multiple SclerosisMetallocenesCarboxylic acidBiophysics010402 general chemistry01 natural sciencesBiochemistryBiomaterialsImmunoenzyme Techniques[ CHIM.CATA ] Chemical Sciences/CatalysismedicineElectroanalytical methodElectrochemistryMoietyHumansFerrous CompoundsAntigensComputingMilieux_MISCELLANEOUSAutoantibodieschemistry.chemical_classification010405 organic chemistryChemistryMultiple sclerosisOrganic ChemistryAutoantibodyGlycopeptidesGeneral Medicine[CHIM.CATA]Chemical Sciences/Catalysismedicine.diseaseGlycopeptide0104 chemical sciences3. Good healthAmino acidSolutionsBiochemistryMolecular ProbesGoldCyclic voltammetryChromatography Liquid

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A P-chirogenic β-aminophosphine synthesis by diastereoselective reaction of the α-metallated PAMP–borane complex with benzaldimine

2004

International audience; The diastereoselective synthesis of a P-chirogenic β-aminophosphine ligand with carbon–carbon bond formation of the ethano bridge in a 3:1 ratio via reaction of an α-metallated P-chirogenic phosphine borane with a benzaldimine is described. The diastereoselectivity is attributed to a transition state where the lithium cation chelates the phosphine borane carbanion and the nitrogen of the imine and the attack of the C@N occurs on the face opposite to the P–B bond, due to its interaction with the antibonding P–B bond. The major diastereoisomeric β-aminophosphine borane was then separated and decomplexed into the corresponding β-aminophosphine under neutral conditions a…

010405 organic chemistryLigandOrganic ChemistryImineEnantioselective synthesisAsymmetric synthesisBoranesAminophosphineBoraneChiral phosphorous010402 general chemistryAntibonding molecular orbital01 natural sciencesMedicinal chemistryCatalysis0104 chemical sciencesInorganic Chemistrychemistry.chemical_compoundchemistryBoraneOrganic chemistry[CHIM.COOR]Chemical Sciences/Coordination chemistryPhysical and Theoretical ChemistryPhosphineCarbanionTetrahedron: Asymmetry

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Enantiodivergent synthesis of P-chirogenic phosphines

2010

International audience; Several approaches for the enantiodivergent synthesis of P-chirogenic mono- and diphosphines are described, using ephedrine methodology and phosphine borane chemistry. Firstly, both enantiomers of a tertiary phosphine can be obtained starting from the same oxazaphospholidine borane complex, prepared from (+)-ephedrine, when changing the order of addition of the organolithium reagents during the synthetic pathway. The second approach is based on the chlorophosphine boranes, which react with an organolithium reagent, to afford the corresponding phosphines with inversion of configuration. In the case where the chlorophosphine borane reacts with the t-butyl lithium reage…

chemistry.chemical_classification010405 organic chemistryGeneral Chemical EngineeringArylBorane complexesEnantioselective synthesisBoranesAsymmetric synthesisGeneral Chemistry[CHIM.CATA]Chemical Sciences/CatalysisBorane010402 general chemistryOrganolithium reagent01 natural sciencesMedicinal chemistry0104 chemical scienceschemistry.chemical_compound[ CHIM.CATA ] Chemical Sciences/CatalysischemistryEnantiomersDiphosphinesOrganic chemistryChiral phosphinesPhosphineAlkyl

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Design of P-Chirogenic Aminophosphine-Phosphinite Ligands at Both Phosphorus Centers: Origin of Enantioselectivities in Pd-Catalyzed Allylic Reaction…

2020

International audience; We have recently patented an unprecedented stereospecific N→O phosphinyl migration process which transforms P-chirogenic aminophosphines into phosphinites. A fine design of aminophosphine phosphinite ligands (AMPP*) derived from ephedrine and bearing a P-chirogenic center either at the aminophosphine or phosphinite moiety, was performed. The synthesis of AMPP* ligands with P-chirogenic aminophosphine moiety was based on the well-established stereospecific reaction of oxazaphospholidine-borane with organolithium reagents, followed by trapping with a chlorophosphine and borane decomplexation. Concurrently, the preparation of AMPP* ligands with P-chirogenic phosphinite …

Allylic rearrangementPhosphinite010405 organic chemistry[CHIM.ORGA]Chemical Sciences/Organic chemistryOrganic ChemistryDABCOBorane010402 general chemistry01 natural sciencesMedicinal chemistry0104 chemical scienceschemistry.chemical_compoundStereospecificityNucleophilechemistryMoiety[CHIM]Chemical SciencesConformational isomerismThe Journal of organic chemistry

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