Marie-Paule Teulade

Alkylidènediphosphonates et vinylphosphonates: une démarche synthétiques sélective par voie carbanionique

Abstract Phosphonoalkylation of acylchloro-phosphates or -phosphinates in the presence of excess lithium diisopropylamide leads to direct generation of lithiated methylene-diphosphonate anions. This stable type of anion can be either protonated in acidic medium to provide tetrasubstituted methylenediphosphonate or alkylatd. When aliphatic or aromatic aldehydes are added spontaneous formation of vinyl-phosphonates is observed. This process is a simple and convenient route to diphosphonic as well as to vinylphosphonic compounds.

Conversion directe “in situ” des alkyl en vinylphosphonates

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

Carbanions phosphonates α-lithiés: synthèse, basicité comparée et stabilité à l'autocondensation

Abstract Non stabilized α-lithio-α-substituted alkanephosphonates (RO)2P(O)CHR1Li (R1 = H, alkyl, C1) are commonly used as phosphonoalkylating agents. The strength of the conjugated acids (RO)2P(O)CH2R1 is estimated by concurrent metallation. The data checked range from phenylacetylene to toluene in relation with the inductive electronic effects of R and R1. Most of the α-phosphonyl carbanions give stable dimers via thermal self-condensation which is steric (R) and electronic (R1) effects dependent. In addition preparative conditions for some phosphonate precursors are reexamined.

Conversion directe par les alkyllithiens des phosphates en phosphonates α -lithies

Resume Trialkylphosphates (RO) 3 P(O) can be converted into α-lithioalkanephosphonates by treatment with alkyllithiums (R 1 CH 2 Li) in two fold excess.

Synthesis of 1-Formyl 1,1-Dialkylmethylphosphonates

Abstract Preparation of 1-formyl 1,1-dialkylmethylphosphonates is described. A carbanionic route is provided by the condensation of α-lithio α,α-disubstituted methylphosphonates with ethylformate whereas a carbocationic route provided by the acid catalyzed rearrangement of β,β-disubstituted epoxyethylphosphonates is re-evaluated.

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.

A Conveniant Preparation of γ-Formylalkanephosphonates

Abstract Despite their obvious potential as synthetic intermediate, relatively little attention has been directed to the preparation of γ-formylalkane phosphonates. Because of our interest in the possible utilisation of these compounds as starting materials for the preparation of aminophosphonic acids a new approach has been devised.