Ph. Savignac

Les α-cuprophosphonates—iii : Application à la synthése de β-cétophosphonates

Abstract A new, practical, synthesis of β-ketophosphonates relying on the conversion of the organolithium reagent from a dialkyl methylphosphonate into the corresponding organocopper reagent, and its reaction with acyl chlorides is described. The structure of the intermediate organocopper reagents is discussed.

Conversion directe “in situ” des alkyl en vinylphosphonates

Abstract Phosphorus acyl chlorides phosphonoalkylation leads to the direct generation of alkylidenediphosphonates anions convertible into vinylphosphonates.

Préparation et conversion D' ω-formylalkylphosphonates en acides aminocarboxyalkylphosphoniques

Abstract ω-Formylalkylphosphonates by acid hydrolysis of the corresponding acetals obtained from triethylphosphite and bromoacetals has been described. In aqueous solution in the presence of cyanide and amines these compounds give aminonitriles (Strecker) or hydantoins (Bucherer). These reactions give access to a large variety of compounds which by acid hydrolysis (Strecker) or basic then acid hydrolysis (Bucherer) lead to pure aminocarboxyalkylphosphonic acids (phosphonoalanine, etc.).

Animation reductrice des β-cetophosphonates: preparation d'acides aminoalkylphosphoniques

Abstract Diethyl 2-oxo-alkylphosphonates undergo reductive amination in the presence of an amine and sodium cyanohydridoborate (NaBH3CN) in MeOH at Ph 7–7.5. Studies with a large variety of ketophosphonates show that the reaction rate is very sensitive to steric hindrance and is carried out probably via an enaminophosphonate intermediate. Acid hydrolysis of aminoalkylphosphonates gives corresponding phosphonic acids.

Preparation d'acides aminocar☐y-alkylphosphoniques optiquement actifs

Resume La preparation daminonitriles phosphoniques optiquement actifs N-benzyles est realisee en millieu aqueuxapartir daldehydes phosphoniques, dacide cyanhydrique et de (S)(-)α-methylbenzylamine. L excesenantiomerique [ee] est de 50%. Les aminonitriles phosphoniques sont hydrolyses en milieu acide, puis reesterifies et debenzyles sans aucuneepimerisation. La separationt des aminoacides N-benzyles est effectuesoit sur lacide soit sur lester. Toutes les reaction sont controlees par RMN( 1 H, 13 C, 31 P) et lorsque cest possible par CPG.

Reactions de metallation dans la serie des spirophosphoranes a liaison PH. Formation de la liaison PVC

Abstract We report here the generation and reactions of reagents such as A, in which M = Li or Na. The action of various metallation reagents (RLi, R 2 NLi, HNa, NH 2 Na) in THF at room temperature has been tested on 2,2,3,3,7,7,8,8-octamethyl-1,4,6,9-tetraoxy-5-phospha(V)[4.4]spirononane. Only R 2 NLi and NH 2 Na are effective. The metallated intermediate is probably an oxanion rather than a phosphanion. Some coupling reactions of these reagents with various RX and their use in hydroxyspirophosphorane synthesis are described.

Preparation d'acides aminoalkyl phosphoniques a l'aide d'ω-halogenoalkyl amines phosphorylees

Resume Une methode efficace de preparation des acides aminoalkyl phosphoniques simples ou substitues basee sur le principe de protection de la fonction amine par phosphorylation. Phosphorylation damines β-ou γ-bromees suive par phosphonylation de lamine halogenee par reaction dArbuzov avec le triethylphosphite donne linter-mediaire phosphoramide-phosphonate qui peut etre alkyle par divers reactifs. Lelimination du groupe protecteur est realisee par traitement a lacide chlorhydrique aqueux. Lisolement et la purification des acides amino-phosphoniques sont decrits.

AMINATION REDUCTRICE D'ALDEHYDES PHOSPHONIQUES

Abstract Nous reexaminons la reactivite des oxo-2 ethyl et oxo-3 propylphosphonates de diethyle avec lammoniac, la methyl et la dimethylamine a pH 7 en presence de cyanoborohydrure de sodium via lamination reductrice du carbonyle. Les reactions avec lammoniac conduisent a la formation dimino-bis-(alkylphosphonate); la methyl et la dimethylamine conduisent normalement a lobtention daminoalkylphosphonates N-substitues. The reactivity of diethyl-2-oxo ethyl- and 3-oxo propylphosphonates with ammonia, methyl and dimethylamine at pH 7 in the presence of sodium cyanohydridoborate via reductive amination of the carbonyl group has been rexamined. Reactions of diethyl-2-oxoethyl- and 3-oxopropylphosphonates with ammonia give imino-bis-(alkylphosphonates); methyl and dimethylamine give monocondensation products thus permitting the synthesis of N-substituted amino-alkylphosphonates.

α-Substituted Silyl and Phosphonyl Phosphonates. An Extensive Study of their Synthesis and Properties

Abstract Phosphoryl and silyl chlorides phosphonoalkylation lead to the direct generation of phosphonyl-phosphonyl and phosphonyl-silyl carbanions the properties of which are discussed.

ACCÈS [Agrave] L'ACIDE AMINO-2 PROPYLPHOSPHONIQUE OPTIQUEMENT ACTIF

Abstract The reaction of optically active α-methylbenzylamine with phosphonates containing an unsaturated carbon in the β position results in a mixture of cis- and trans-aminovinylphosphonates. Reduction with NaBH4/CH3COOH/THF produces benzylaminopropylphosphonates in good yield and stereoselectivity (72%); the selectivity is closely dependent on the phosphorus environment. Reduction with hydrogen in the presence of Pd/C as catalyst gives better selectivity (90%); however, the reaction is limited to phosphonates bearing a t-Bu substituent. After hydrolysis, debenzylation and purification, we isolated optically active 2-aminopropylphosphonic acid. The rotations are reported.