A-Hydroxyphosphinic acids

Yamagishi, T., Yokonatsu, T., Suemune, K., and Shibuya, S., Enantioselective synthesis of a-hydroxyphosphinic acid derivatives through hydrophosphi-nylation of aldehydes catalyzed by Al-Li-BINOL complex, Tetrahedron, 52, 11725, 1996. 

All the substances 104-110 were evaluated as ATCase inhibitors, using E. coli Histidine-tagged C3 ATCase [100]. All inhibition constants ranging from 190 to 3,600 nM were at least ten times higher than the value of 16 nM of the reference molecule PALA. The best inhibition constant was found for the a-hydroxyphosphinic acid 105 = 190 nM). The cyclic azaphosphinanes 106... 

Diastereoselective reaction of the chiral aldehyde (Fig. 8.3) with diethylphos-phife was mediated by LLB catalytic system (Ln/Li/BINOL) with the diastereoi-somers ratio 75 25, same transformation catalyzed by ALB system gave 80 20 ratio of the diastereoisomers [173]. Synthesized j -amino-a-hydroxyphosphinic acids were considered as key intermediates in the preparation of potential inhibitors of human renin and HIV-protease. 

Yamagishi T, Suemune K, Yokomatsu T, Shibuya S (2002) Asymmetric synthesis of /J-amino-a-hydroxyphosphinic acid derivatives through hydrophosphinylation of a-amino aldehydes. Tetrahedron 58 2577-2583... 

Similar treatment of 1.1-spiro compounds leads to different results depending upon the number of atoms in the iro ring. The fivemiembered compound 207 a yields the cyclic 2-oxyphosphinic acid ester 208 a (60%) and only 8% of the 4-hydroxyphosphinic acid ester 209a (R = H). Acetic acid ist not necessary for these transformations. 207b and c (R = D, CH3) react in a similar manner ... 

Reaction of olefins with P, Oj and H2O yields /3-hydroxyphosphinic acids in a complex reaction ... 

New y-ethoxycarbonyl- and ot-amino-alkyl-hydroxyphosphinic acid derivatives (366) and (367) were conveniently prepared by Michael addition or Kabachnik-Fields reaction of a new precursor, benzyloxymethyl hydrogen-phosphinate (368), with a,p-unsaturated esters or imines (Scheme 94). " Phosphinic acid inhibitors (369) of Cathepsin C were synthesized by addition of methyl acrylate to the appropriate a-amino phosphinic acid and by... 

The amount of chlonon thus produced is obviously a measure of the amount of acid chloride present in the mixture. The acid is isolated in the form of an insoluble barium salt, the structure of wliich follows from the fact that the acid is monobasic and on boiling with water is converted into the hydroxyphosphinic acid ... 

NMR spectroscopy was applied in the enantiomeric excess determination of (iV,iV-dimethyl-(2,2,2-trifluoro-l-phenylethyl)amine-C,A)palladium complexes of a-amino acids.Dunina et al. used NMR spectroscopy and a P -chiral phosphapalladacycle for the enantiomeric purity determination of a-amino acids. P NMR spectroscopy was also used in the enantiomeric excess determination of N,C o///5< -palladated complexes of P-chiral phosphines. A ferrocene-based reagent (i p,successfully designed for the chiral recognition of /3-hydroxyphosphines and the discrimination of ( )-bis(diphenylphosphino)-1,1 -binaphthyl. 

Sodium iodide acetic acid a-Hydroxyphosphine oxides from 0X0 compds. 

The electrochemical reduction of mono- and bis(acyl)phosphine oxides was observed to lead to the corresponding radical anions/ In the field of optically active phosphine oxides, the resolution of l-butyl-3-methyl-3-phospholene oxide with TADDOL derivatives was described/ The preparation of the enantiomers of BINAP and its derivatives was summarized in a review/ The deracemization of tert-butyl-phenylphosphine oxide using dibenzoyltartaric acid afforded one enantiomer in a configurationally stable form, in contrast to suggestions in the literature and to general opinion. The enantiomer of the secondary phosphine oxide was utilized in the preparation of a-hydroxyphosphine oxides (Scheme 64). The adducts were obtained in >95% ee and in >95% de. °... 

The desired acids 31 were obtained by simply bubbling CO2 through a solution of the deprotonated phosphine boranes 4 and could be quantitatively reduced to (3-hydroxyphosphines 32. The hydroxyl group of 32 was then mesylated or tosylated in good yields to alford compounds 33, which were employed to prepare other compounds like P/N and P/S bidentate ligands (see later in this section) and unsymmetric BisP ligands (Section 5.2.1.3). The yields of compounds 31-33 are listed in Table 5.7. 

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