Amino compounds phosphonic esters

The Kabachnik Fields reaction, which involves the hydrophosphonylation of phos phites with imines generated in situ from carbonyl compounds and amines, is an attractive method for the preparation of a amino phosphonates. Optically active a amino phosphonic acids and their phosphonate esters are an attractive class of compounds due to their potent biological activities as nonproteinogenic analogues of a amino acids. Therefore, considerable attention has been given to their enantio selective synthesis by hydrophosphonylation of preformed imines, using either metal based catalysts or organocatalysis [107]. 

It might also be noted that, coupled with the facile formation of an [amino(l-hydroxy)alkyl]phosphonic ester, there exists a tested method for the dehydroxylation of such a system this consists in acylation [PhOC(S)Cl, R3N] at OH in the A-protected compound, followed by de-0-acylation brought about with (Mc3Si)3SiH in the presence of aibn. ... 

Phosphorus-containing compounds provide useful substrates for ozonolysis reactions as well and can provide several products depending on the reaction workup. Several biological uses exist for -amino-a-hydroxy phosphonic acid derivatives and they can be readily prepared by ozonolysis of Al-(ethoxycarbonyl)-/3-amino-Q -methylene phosphonic esters after reductive workup with sodium borohydride (eq 54). When the reaction mixture is treated with sodium hydroxide in MeOH, an anomalous ozonolysis reaction occurs and cleavage of the methylene as well as the carbon-phosphorus bond occurs to yield (V-(ethoxycarbonyl)-a-amino methyl carboxylic esters. 

Antagonists of metabotropic glutamate receptors and G-protein-coupled receptors associated with various neurodegenerate diseases have been prepared by proline-catalyzed direct a-amination reactions (Scheme 2.30) [7c]. Both, indane carbaldehyde 10 and analogous compounds having an ester functionality [leading to l-aminoindan-l,5-dicarboxylic acid (AIDA)] and or a phosphonate substituent [(RS)-l-amino-5-phosphonoindan-l-carboxylic acid APICA], all reacted with di-... 

Many communications have concentrated on specific amino phosphonic acids or derivative types. Thus, esters of phosphonoaminoacetic add were obtained by the reactions between trialkyl (ethyl) phosphite and (218) and which are thought to proceed via the phosphorane (219). A sequence has been presented for the preparation of the mono- and di-benzyl esters of N-chz protected (a-aminoben-zyl)phosphonic acid. A synthesis of (aminomethylene)bisphosphonic acid from dibenzylamine, dibenzyl hydrogenphosphonate and triethyl orthoformate has been noted and the asymmetric hydrogenation of (220) in the presence of chiral phosphine catalysts yields samples of (221) with e.e.s of 63-96%. The pyrrolidine-based compound (222) has been prepared from methyl S)-N-methoxycarbonyl-4-oxo-2-pyrrolidinecarboxylate and iV-coupled 4-amino-butanal diethyl acetals were the starting materials in syntheses of the pyrrolidine-2-phosphonic add derivatives (223) in which Z represents the iV-protected amino add or peptide moiety. ... 

There are other reactions which lead from prop-2-ynyl compounds to allenic phospho-nic acid derivatives. The alkylation of diethyl hydrogenphosphonate with 3-bromopropy-ne under phase transfer conditions yields a mixture of diethylpropadienyl- and (prop-l-ynyl)-phosphonates in 85 15 ratio " The action of heat on a mixture of prop-2-ynol and a phosphoramidous ester, (RO)2PNR 2, results in elimination of R 2NH followed by its re-addition to the rearranged residue to afford a dialkyl (2-amino-prop-1-enyl)-phosphonate. ... 

The reactions between methyl 4-oxopentanoate and phosphinic esters in the presence of ammonia yield the 4-amino-4-phosphinoylpentanoic acids (218) (synthesized as analogues of phosphinothricin), although difficulties may be encountered in the purification of these compounds so prepared ". The initial adduct formation between the ketones 219, ammonia and diethyl hydrogenphosphonate can be succeded by the conversion of the products (220) into pyrrolidine- and piperidine-2-phosphonic acids (Scheme 23). ... 

Amino-l-hydroxyethyl)phosphonic acid occurs in the plasma membrane of Acanthamoeba castellani and the 2R isomer is formed, in that organism, by the hydroxy-lation of (2-aminoethvl)phosphonic acid This biosynthesis step in vitro has been studied by Hammerschmidt" who synthesized various chiral deuterium-labelled derivatives of both compounds using the isotopically labelled 2-benzyloxyethanal in Abramov reactions to obtain, initially, the dimethyl (2-benzyloxy-l-hydroxyethyl)phosphonate (362). This ester was resolved through the diastereoisomeric carbamates 363 the separated carbamates were sequentially de-l-O-protected, silylated at the a-HO group, debenzylat-ed and, by means of the Mitsunobu reaction, converted into dimethyl [2-eizido- -(tert-butyldimethylsilyloxy)ethyl]phosphonates. Subsequently, standard reactions were used to transform the latter into the diastereoisomeric, isotopically labelled (2-amino-1-hydroxy-ethyl)phosphonic acid. 

The main three compounds already used in the UK for fabric protection appear to be on the accepted list for the US standard. For cotton-based fabrics the major candidate is phosphonic acid (3-[hydroxymethyl]amino)-3-oxypropyl dimethyl ester, sold as Pyrovatex. It is already used for apparel and does not meet the definition of toxic under the Federal Hazardous Substances Act (FHSA). 

An array of 16 enantiomeric pairs of chiral phosphate, phosphonate and phosphinate esters was used to establish the breadth of stereoselective discrimination inherent within the bacterial phosphotriesterase and 15 mutant enzymes. The results demonstrate that the catal5hic properties of the wide-type of phosphotriesterases can be exploited for the kinetic resolution of a wide-range of compounds and that the active site of this enzyme is remarkably amenable to structural perturbations via amino acid substitution. The first use of dialkyl phosphates as stereodirecting... 

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