Aurelio Munoz

Spirophosphoranylation d'α-aminoacides—I : Preparation et tautomerie1

Resume Une vingtaine de spirophosphoranes nouveaux (Tableaux 1 et 2) ont ete prepares en faisant reagir les &alpha-aminoacides sur des composes du phosphore tricoordine possedant un groupement partant convenable. Dans le cas du compose 1i , un equilibre chaǐne-cycle P III P v a ete mis en evidence.

Esters boriques d'alditols. Synthèse, structure et stabilité en solutions dans l'eau

Abstract Borate esters were obtained by treating d,l -threitol, xylitol, l -arabinitol, 1,2:5,6-di- O -isopropylidene- d -mannitol, d -mannitol, d -glucitol, galacitol, and l-deoxy-1-methylamino- d -glucitol with boric acid in water solution and in the presence of potassium hydroxide. Their structures were established by 11 B- and 13 -C-n.m.r. spectroscopy. Spiranes obtained with glycerol, erythritol, and ribitol are unstable in water solution.

Per - bicyclophosphoranylation d'alditols

Abstract Reaction of bicyclophosphane 1 with glycol 2 , glycerol 3 , erythritol 4 , L(-)arabitol 5 and dulcitol 6 leads to the corresponding per-alkoxybicyclophosphoranes 2p - 6p which are in tautomeric equilibrium with the phosphates forms 2p ′ - 6p ′.The amount of these latters increases regularly from traces to 24%.

Un exemple d'equilibre tautomere phosphite phosphorandure

Resume A compound has been isolated whose elemental analysis, nmr and IR data are consistent with an equilibrium phosphoranide phosphite.

Les phosphoranes à liaison P-H acides de Bronsted - réactivité de leurs bases conjuguées - synthèse de nouveaux phosphoranes ioniques

Abstract Hydridophosphoranes prepared from α-hydroxyacids, react in presence of triethylamine, on sulfur, selenium, Lawessons reagent, tosylazide giving triethylammonium salts of phosphoranes with exocyclic anionic group: [sbnd]S−, [sbnd]Se−, [sbnd]PS2[sbnd]C6H4[sbnd]OCH3(p), [sbnd]N[dbnd]SO2[sbnd]C6H4[sbnd]CH3(p). The compounds obtained with sulfur and selenium represent good models of intermediates of substitution reactions on thio or (and) seleno phosphoric (phosphonic) esters. Reacting with trimethylchlorosilane, conjugated bases of the preceeding hydridophosphoranes, gave instead of the corresponding trimethyl silyl phosphoranes, the isomeric phosphorous ester. Les phosphoranes a liaison P[sbnd]H prepares a partir des α-hydroxyacides reagissent en preence de triethylamine, sur le soufre, le selenium, le reactif de Lawesson, 1′ azoture de tosyle pour conduire a des phosphoranes portant les groupements anioniques: [sbnd]S−, [sbnd]Se−, [sbnd]PS2[sbnd]C6H4[sbnd]OCH3SO2[sbnd]C6H4[sbnd]CH3(p). Les compose...

Epimerization of an optically active hexaco-ordinated phosphorus compound: kinetic studies

The phenomenon of second-order asymmetric transformation often encountered for optically active spirophosphoranes has made possible the isolation of the optically pure hexaco-ordinate phosphorus compound (2). It was possible to follow the epimerization of the hexaco-ordinate phosphorus atom by n.m.r. spectroscopy and polarimetry for dimethyl sulphoxide solutions. The values of ΔG‡(21.3 kcal mol–1) are very close to those observed for pentaoxyspirophosphoranes.

Stabilisation de cations oxophosphenium par liaisons datives P←N

Resume Phosphorochloridites prepared from 8-hydroxyquinolines exist in equilibrium with phosphenium cations stabilized by one or two P←N bonds.

Stabilisation d'ozonides du phosphore

Abstract We have obtained phosphorus ozonides ( 3b , 4b and 5b ) in which phosphorus atom is hexacoordinated. In solution, these adducts are more stable than pentacovalent phosphorus homologs (ΔC* = 23 kcal.mole−1 for 4b )

Synthesis of salts of a pentaoxyspirophosphorane having a P–OH bond

The pentaoxyspirophosphorane (1) having a P–OH bond was prepared from the reaction of POCl3 with benzilic acid and isolated as its triethylammonium salt: this compound and the corresponding NN-dimethylformamidinium salt have also been synthesised from the spriophosphorane (2), having a P–H bond, by oxidation with Me2SO.

SYNTHESE ET MECANISME DE FORMATION D'AMINOPHOSPHONATES SOUS ULTRASONS

Abstract Phosphonates 1a, 1b, 1c react with imine 2 following a polar mechanism without any ultrasonic effect. Starting with phosphonate 1d, a more complex (polar and radical) mechanism has been pointed out. This latter reaction was accelerated under ultrasound.