Henri-Jean Cristau

Regio- and stereoselective synthesis of 2-amino-1-hydroxy-2-aryl ethylphosphonic esters

Abstract A highly regio- and diastereoselective synthesis of 2-amino-1-hydroxy-2-aryl ethylphosphonic esters was achieved by opening trans 1,2-epoxy-2-aryl ethylphosphonic esters with 28% NH 3(aq.) in methanol.

A convenient one-pot synthesis of phosphino-dipeptide analogs

Abstract A general one-pot synthesis is described for the preparation, in good overall yields, of phosphinopeptides as building blocks for peptide synthesis in the field of new enzyme inhibitors. This method, consisting of the addition of alkyl hypophosphites to imines and then in the Michael-addition of the resulting alkyl α-aminophosphonites on acrylates, affords the possibility of variations for the substituents in α and β position to the phosphorus atom and in α position to the nitrogen atom.

Preparation of phosphinodipeptide analogs as building blocks for pseudopeptides synthesis

A simple and effective preparation of phosphinodipeptides, in good overall yields, has been developed. This one pot procedure, allowing the variation of the substituents in α and/or β position to the phosphorus atom and also in α position to the nitrogen atom, consists in the addition of alkyl hypophosphites to imines, followed by Michael-addition on acrylates. To show the value of phosphinodipeptides analogs 1 as synthetic intermediates, selective deprotections of the three functional groups are described.

Synthesis of bis(hydroxymethyl)phosphorylated compounds, analogs of α-aminophosphonic acids or alkylidenebisphosphonic acids

Abstract The synthesis of two new series of functional phosphines oxides is described: analogs of glyphosate [α-aminomethylbis(hydroxymethyl)phosphine oxide] and bisphosphonic acids [bis(hydroxymethyl)phosphoryl methylphosphonic acid] substituting the phosphonic group [–P(O)(OH) 2 ] by the bis(hydroxymethyl)phosphoryl group [–P(O)(CH 2 OH) 2 ], have been synthesized in good yields, using the bis(benzyloxymethyl)chloromethyl phosphine oxide as a common precursor. The further purpose of this work is to evaluate the biological interest of the bis(hydroxymethyl)phosphoryl group in comparison to the phosphonic group present in a wide range of biological molecules.

A convenient synthesis of tetrazole, precursors of α-dialkylated α-amino acids, by reaction of trimethylsilyl azide with α-dialkylated β-ketoesters

The Schmidt rearrangement using trimethylsilyl azide with various α-dialkylated β-keto esters affords a convenient synthesis of tetrazole, precursors of α-dialkylated α-amino acids.

Unexpected Rearrangement of Diethyl (±)(S,S)-1,2-epoxy-2-Phenylpentylphosphonate by NH 3(aqu.) : An Easy Entry to Ethyl 1-Formyl-1-Phenylbutylphosphonate

A simple reaction of diethyl ( - )(S,S)-1,2-epoxy-2-phenylpentylphosphonate with 28% NH 3(aqu.) in MeOH led to the ethyl 1-formyl-1-phenylbutylphosphonate in excellent yield. The procedure consists simply in stirring the substrate and 28% NH 3(aqu.) in MeOH, at 40;C.

Regio- and Stereoselective Synthesis, Solution Conformations of 2-Amino-1-hydroxy-2-arylethylphosphonic Esters and Acids

Phosphonic acids with heteroatoms in the α and/or β positions have attracted considerable interests because of their use as inhibitors of proteolytic enzymes or agents affecting the growth of plants. According to this fact, we have developed new, highly regioand diastereoselective way of synthesis of 2-amino-1-hydroxy-2arylethylphosphonic esters1 and acids by opening of trans 1,2-epoxy2-arylethylphosphonic esters with 28% NH3(aqu.) in methanol. Concerning the diastereoselectivity, the obtained esters and acids are probably the unlike diastereoisomers. Conformational studies (NMR, IR) confirm SN2 mechanism and show the formation of hydrogen bond between (NH2). . . (OH) moieties in case of esters, whereas for acids formation of hydrogen bond between (NH2). . . (P O) predominate.2

FORMATION OF AMINOMETHYLPHOSPHONIC ACIDS AND MONOESTERS FROM AMINOMETHYLPHOSPHONATES

Abstract Correcting a previous preliminary communication, the reaction between diethyl N-benzoyl α-aminomethylphosphonate and PCl5, is shown to afford the corresponding aminomethylphosphonic acids and monoesters instead of the previous mentioned oxazaphospholene.

Synthesis of New Cα,α-Diarylaminomethylphosphonic Acids and their Esters

Abstract A procedure for the preparation of N-protected 1 or unprotected Ca,a-disubstituted (diarylaminomethyl)-phosphonic acids and their esters is reported.1 This method is a generalisation of the Kabachnik-Fields method described in the literature.2