Francoise Plenat

The preparation of phosphono peptides containing a phosphonamidate bond

Abstract The synthesis of phosphono peptides containing phosphonamidate bond by means of phosphorylation of amino acid esters with N-protected aminoalkylphosphonochloridates, is accompanied by the formation of an unidentified side-product. The factors influencing this reaction were studied in some detail.

PREPARATION OF BENZYL N-BENZYLOXYCARBONYLAMINOPHOSPHONATES AND -AMINOPHOSPHONITES-THE SCOPE AND LIMITATIONS OF O-BENZYL-N, N′-DICYCLOHEXYLOISOUREA METHOD

Abstract Protection of the amino group of aminophosphonic and aminophosphonous acids with benzyl chloro-formate followed by esterification of the TV-protected derivatives with O-benzyl-N,N′-dicyclohexylo-isoureas is described. The esterification of aminobenzylphosphonic and aminobenzylphosphonous acids was studied in some details in order to discuss the scope and limitation of this procedure. The differences in the reactions of aminoalkylphosphonic and aminoalkylphosphonous acids are pointed out.

Nouvelle synthese stereoselective de disels de botadiene-1,3 ylene-1,4 bisphosphoniums

Abstract A new way to 1,4 butadienylene bisphosphonium salts 2 is given, using a base-catalyzed double isomerization process on acetylenic precursors 3 . The precursor can be synthetized by nucleophilic substitution of 1,4-diiodo 2-butyne with triphenylphosphine. The selection of the 1,4-dihalo 2-butyne has a strong influence on the course of the reaction which, besides that, can lead to exclusive formation of a new stabilized ylid-disalt 5 . The stereoselectivity of the t.butylamine induced double isomerization allows the isolation of the kinetic product, the (Z, E) 1,4-butadienylene bisphosphoniun salt, which is then readily converted into the more stable (E, E) isomer.

Synthesis and structural studies (1H, 13C, 31P NMR and X-ray) of new C-bonded cyclotriphosphazenes with heterocyclic substituents from novel phosphinic acid derivatives

Three new C-bonded cyclotriphosphazenes, [N3P3(2-thienyl)6], 2, [N3P3(3-thienyl)6], 4, and [N3P3(3,3′-bithienyl-2,2′-ylene)3], 6, have been prepared by two new synthetic procedures and are the first examples of non-spiro and trispirocyclotriphosphazene derivatives composed of thiophene and 3,3′-dithiophene substituents, respectively. Their 1H, 13C and 31P NMR parameters are given. The solid state structures of 2, 4 and 6 have been determined by X-ray crystallography.

Use of Phosphonium Diylids in Organic Synthesis

Abstract Reactivity of phosphonium diylids towards such carbonyl compounds as ketones, esters, carbonates, amides… has been investigated. The Wittig reaction was obtained with some amides.

Reactivity of phosphonium diylids with aldehydes and ketones

Abstract Non-stabilized and semi-stabilized phosphonium diylids of the type (C 6 H 5 ) 2 P(CHR)(CHLiR) ( 5 ) show a greater nucleophilic reactivity toward carbonyl compounds than the corresponding monoylids (C 6 H 5 ) 2 P(CHR)(CH 2 R) ( 8 ). Thus diylid 5a reacts readily at room temperature with sterically hindered ketones such as fenchone or di-t-butylketone. However, the residual negative charge in the intermediate adduct 13 slows the decomposition to Wittig products, and is probably responsible for the observed changes (generally enhancement) in the E -selectivity in the case of non-stabilized as well as semi-stabilized ylids.

Synthesis of new phosphorus 2,4,5-imidazolidinetriones

Abstract Phosphorus 2,4,5-imidazolidinetriones are obtained in two different ways the synthesis of dithiophosphate and phosphomum salt derivatives involves the reaction between a common N-chloromethyl heterocycle and corresponding phosphorus partners, while the preparation of phosphonate and phosphine oxide imidazolidinetriones is done by two multi-step synthesis starting from different phosphorus phthalimides

Arylation of red phosphorus: A new way to triphenylphosphine oxide and triphenylphosphine

Abstract Nickel bromide catalyses the arylation of amorphous red phosphorus. This provides a new way to triphenylphosphine oxide and triphenylphosphine

Synthesis and X-ray structural studies of new spiro-cyclotriphosphazenes

The series of four cyclotriphosphazenes containing biphenyl and phenyl groups, [N3P3(C12H8)3- nPh2n], where n = 0–3, (1–4 respectively), has been completed by the synthesis of two new C-bonded spiro-cyclotriphosphazenes, [N3P3(C12H8)2Ph 2] 2 and [N3P3(C12H8)Ph4] 3. They have been fully characterised and X-ray structural analysis shows that both compounds have a planar cyclotriphosphazene ring with less overall molecular rigidity compared to the trispirocyclic analogue, 1.

Polarographic Investigations of Functionalized Alkanephosphonic Acids. Part II

Abstract Investigations on the polarographic activity of phosphonic acids are described. The electrochemical reduction of phosphorous acid and various phosphonic acids was studied in some details to discuss the scope and the limitation of this process. The possible course of the polarographical electroreduction of the phosphonic function is delineated.