title: Stereospecific Synthesis of α- and β-Hydroxyalkyl P-Stereogenic Phosphine-Boranes and Functionalized Derivatives: Evidence of the P=O Activation in the BH3 -Mediated Reduction.
abstract: Access to hydroxy-functionalized P-chiral phosphine-boranes has become an important field in the synthesis of P-stereogenic compounds used as ligands in asymmetric catalysis. A family of optically pure α and β-hydroxyalkyl tertiary phosphine-boranes has been prepared by using a three-step procedure from readily accessible enantiopure adamantylphosphinate, obtained by semi-preparative HPLC on multigram scale. Firstly, a two-step one-pot transformation affords the enantiopure hydroxyalkyl tertiary phosphine oxides in good yields and enantioselectivities. The third step, BH3 -mediated reduction, allows the formation of the desired phosphine-boranes with excellent stereospecifity. The mechanistic study of this reduction provides new evidence to elucidate the crucial role of the pendant hydroxy group and the subsequent activation of the P=O bond by the boron atom.
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France).
authors.forename: Sébastien
authors.initials: S
authors.lastname: Lemouzy
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France).
authors.forename: Duc Hanh
authors.initials: DH
authors.lastname: Nguyen
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France).
authors.forename: Valentine
authors.initials: V
authors.lastname: Camy
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France).
authors.forename: Marion
authors.initials: M
authors.lastname: Jean
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France).
authors.forename: David
authors.initials: D
authors.lastname: Gatineau
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France).
authors.forename: Laurent
authors.initials: L
authors.lastname: Giordano
authors.affiliation: Spectropole Aix Marseille Université, 13397, Marseille (France).
authors.forename: Jean-Valère
authors.initials: JV
authors.lastname: Naubron
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France).
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vanthuyne
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France). damien.herault@centrale-marseille.fr.
authors.forename: Damien
authors.initials: D
authors.lastname: Hérault
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France). gerard.buono@centrale-marseille.fr.
authors.forename: Gérard
authors.initials: G
authors.lastname: Buono
keywords: boranes; phosphanes; reduction; stereospecificity; vibrationsl spectroscopy