Józef Drabowicz

Aminophosphonic Acids - Phosphorus Analogues of Natural Amino Acids.Part 1: Syntheses of α-Aminophosphonic Acids

This review presents a comprehensive account of methods which are commonly applied for the synthesis of alpha- aminophosphonic acids. In the following order, protocols based on the methodologies listed below are discussed: a) simultaneous formation of P-C-N systems; b) nucleophilic substitution with phosphoroorganic nucleophiles; c) additions of the P-H functions to multiple C-N bonds; d) alpha-amination of phosphonates and functionalized alkylphosphonates; e) modifications of the side chain of aminoalkylphosphonates; f) modifications of phosphorus functions and h) modifications of functions containing nitrogen.

Asymmetric addition of dialkyl phosphite and diamido phosphite anions to chiral, enantiopure sulfinimines: a new, convenient route to enantiomeric α-aminophosphonic acids

Abstract Lithium or sodium dialkyl phosphites and diamido phosphites 3 undergo addition to (+)-(S)-benzylidene-p-toluenesulfinamide 2 affording N-sulfinyl-α-aminophosphonates 4 in a diastereoisomeric ratio from 63:37 to 94:6. The major diastereoisomers formed in addition of lithium dimethyl phosphite 3a and lithium bis-diethylamido phosphite 3e to (+)-(S)- 2 were separated and converted into enantiopure (+)-(R)- and (−)-(S)-α-aminobenzyl phosphonic acids 5 , respectively.

Novel approach for the simultaneous analysis of glyphosate and its metabolites

A novel approach for the simultaneous analysis of glyphosate (PMG), and aminomethylphosphonic (AMPA, GlyP), N-methylaminomethylphosphonic (MAMPA. SarP) and methylphosphonic (MPA) acids is presented. This includes a preliminary 31P NMR analysis of mixtures of PMG, MPA, AMPA and MAMPA, their further derivatization to volatile phosphonates by means of the trifluoroacetic acid-trifluoroacetic anhydride-trimethyl orthoacetate reagent and subsequent MS [chemical ionization (CI) MS, GC-CI-MS, GC-electron impact ionization MS] and/or GC-flame ionization detection (FID) analysis of the products of derivatization. The detection limits of PMG, AMPA, MAMPA and MPA by means of GC-CI-MS and GC-FID were determined. The calibration graphs (GC-FID) for these derivatives were in the range 0.1 to 100 nmol linear and sufficiently reproducible for quantitative determinations. The applicability of the method was demonstrated during the analysis of water samples fortified with PMG, AMPA and MAMPA, characterized by recoveries of >95%.

New procedures for the resolution of chiral tert-butylphenylphosphine oxide and some of its reactions

Abstract Racemic t -butylphenylphosphine oxide was resolved via formation of diastereoisomeric complexes with (+)-( R )-1,1′-binaphthalene-2,2′-diol and (+)-( S )-mandelic acid. With the latter complexing agent, separation of the essentially enantiopure (−)-( S )-enantiomer was achieved in a single complexation process. Addition of paraformaldehyde to this enantiomer gave α-hydroxymethyl- t -butylphenylphosphine oxide with high stereoselectivity and retention of configuration at phosphorus while its reaction with methyl bromoacetate in methanol/sodium methoxide resulted in the formation of methyl t -butylphenylphosphinate with inversion at phosphorus.

An Improved Method for Oxidation of Sulfides to Sulfoxides with Hydrogen Peroxide in Methanol

Abstract A variety of oxidative methods have been used for the preparation of sulfoxides from the corresponding sulfides2. However, only few of them permit the oxidation in a selective manner. These methods involve for example sodium metaperiodate3, dichloroiodobenzene4 and t-butyl hypochlorite5 as oxidising agent. It should be noted that it is necessary to use them in equivalent amounts in respect to sulfide in order to avoid the over-oxidation or α-halogenation reaction.

Chiral t-butylphenylphosphinothioic acid: A new NMR solvating agent for determination of enantiomeric excesses of sulfoxides

Abstract (−)-(S)- t -Butylphenylphosphinothioic acid forms with dialkyl andaralkyl sulfoxides diastereomeric dynamic systems the 1 H NMR spectra of which show typical anisochronism of the diastereotopic S-alkyl groups. The magnetic nonequivalence observed even for δ protons, is great enough to determine the e.e. values of sulfoxides having relatively long alkyl chains (e.g. n -butyl)

Simultaneous analysis of biologically active aminoalkanephosphonic acids

A new approach for simultaneous analysis of biologically active aminoalkanephosphonic acids, namely glyphosate, phosphonoglycine, phosphonosarcosine, phosphonoalanine, phosphono-beta-alanine, phosphonohomoalanine, phosphono-gamma-homoalanine and glufosinate, is presented. This includes a preliminary 31p NMR analysis of these amino acids, their further derivatization to volatile phosphonates (phosphinates) by means of trifluoroacetic acid-trifluoroacetic anhydride-trimethyl orthoacetate reagent and subsequent analysis of derivatization products using MS and/or GC-MS (chemical ionization and/or electron impact ionization).

Biocatalytic syntheses of chiral non-racemic 2-hydroxyalkanephosphonates

A series of 2-oxoalkanephosphonates 2 were screened for reduction with Geotrichum candidum. Only diethyl 2-oxopropanephosphonate 2a underwent asymmetric reduction to give (+)-(R)-diethyl 2-hydroxypropanephosphonate 3a with 98% e.e. In turn, a series of racemic 2-hydroxyalkanephosphonates 3 were acetylated under kinetic resolution conditions in the presence of various lipases to give the corresponding 2-acetoxyalkanephosphonates 4 and recovered alcohols 3 in good yields and with e.e. up to 93%.

Absolute configurations, predominant conformations, and tautomeric structures of enantiomeric tert-butylphenylphosphinothioic acid

Vibrational absorption and circular dichroism spectra of dextrorotatory, levorotatory, and racemic mixture of tert-butylphenylphosphinothioic acid have been measured in CCl(4) solutions in the 2000-900 cm(-1) region. The conformations for both tautomeric structures of (S)-tert-butylphenylphosphinothioic acid are investigated using the B3LYP functional with the 6-31G* basis set. For the most stable conformation, the absorption and VCD spectra are predicted ab initio using the B3LYP functional with 6-31G*, 6-311G(2d, 2p), 6-31+G, and 6-311G(3df, 3pd) basis sets. A different functional, B3PW91, was also used with the 6-31G* basis set. The predicted spectra are compared to the experimental spectra. The comparison indicates that (-)-tert-butylphenylphosphinothioic acid is of the (S)-configuration and exists in only one tautomeric structure and one conformation in CCl(4) solution.

A highly efficient asymmetric synthesis of β-aminophosphonic acids, via addition of α-phosphonate carbanions to chiral, enantiopure sulfinimines

Addition of α-phosphonate carbanions to (S)-sulfinimines 1 affords N-sulfinyl β-aminophosphonates 2 in a diastereoisomeric ratio from 5:1 to 10:1; the major diastereoisomers of 2, after separation, are converted to the corresponding β-aminophosphonates 3 or to (+)-β-amino-β-phenylethane phosphonic acid 4, whose absolute configuration was established as (R) by X-ray crystallography.