Phosphonic acid, diesters

Phosphonous acid diesters undergo the Arbusov reaction with a wide variety of organic halides, giving esters of secondary phosphinic acids, as is demonstrated in Eq. (88) ... 

In turn, for the phosphonic acid diester 95, stereoselectivity of the native phosphodiesterase was enhanced by over three orders of magnitude by alteration of the pA a values of the leaving group phenol. Eor example, for X = C02Me, Y = H the stereoselectivity was 5000 higher than for X = NO2, Y = 2-F. ... 

Firestone, R.A.. Hydroxy- and imino-containing phosphonic acid diesters, Merck, U.S. Patent Appl. US 3784590, 1974 Chem. Abstr. 80. 60031, 1974. 

Arylhydrazones of 1- and (2-oxoalkyl)phosphonic acid diesters cyclize in polyphosphoric acid to give indolephosphonic acid diesters e.g., (277) from (276), and (279) from (278),... 

The synthesis of phosphonic acid derivatives by the direct oxidation of those of the corresponding phosphonous acid has been afforded very little interest (Chapter 2, Section VI.c), unlike the more controllable synthesis of derivatives of the thio- or seleno-phos-phonic acid derivatives (Chapter 5, Section II.B.4). In the present instance, the oxidation of A -protected (fmoc) (l-aminoalkyl)phosphinic esters has been carried out with NaI04 with high yields. Quantitative yields of (aminoalkyl)phosphonic acids were obtained in oxidation reactions with bromine water and with HgCl2-H20. In an alternative approach (Scheme 59), the A -protected (cbz) ethyl(l-aminoalkyl)phosphinate is initially converted into a (l-aminoalkyl)phosphonous acid diester, which is then subjected to the Atherton procedure to achieve change in valence at phosphorus. ... 

Alkene-,alkyne-,aryl-phosphonic and phosphinic acids.-(of-Stannylalkyl)phosphonic acid diesters have been employed to prepare alkenylphosphonic diesters. Treatment of the tin compounds (251) (generated in situ) with an aldehyde R CHO at -70 yielded a mixture of ( ) and (Z) isomers of (252), the proportions being controlled essentially by... 

Physical constants of some H-phosphonic acid diesters... 

The vibrational frequencies that correspond to these absorption bands for H-phosphonic acid diesters as well as the characteristic absorption bands of some of their representatives are summarized in Table Al. 

It has been established that the hydrolysis of dialkyl H-phosphonates is general-base and general-acid catalyzed [18]. The hydrolysis of phosphonic acid diesters is facilitated significantly under basic conditions. The mechanism of the base-catalyzed hydrolysis of dimethyl H-phosphonate has been proposed to take place according to the following scheme [19] ... 

The addition of H-phosphonic acid diesters neat or in solvent to the aryUdenalkylamines [45] or to the Schiff base precursors (readily available by the condensation of primary with aldehydes) is one of the best synthetic routes to a-aminophosphonic acids [15,46-50],... 

A kinetic study of the reaction of parasubstituted A-benzylidene methylamines with dialkyl phosphonates reveals that below the isokinetic temperature P (where for a given azomethine the rates of addition for the different phosphonic acid diesters are equal), the following order of reactivity is observed, depending on the type of the alkoxy substituents at the phosphorus atom [51] ... 

A-(phosphonomethyl) glycine is obtained in a good yield by reacting the sodium salt of tris-(carboxymethyl)-hexahydro-5-triazine with phosphonic acid diesters [83]. 

AT-(phosphonomethyl) glycine has been obtained from diketopiperazine, formaldehyde, and H-phosphonic acid diesters followed by hydrolysis [85]. 

Heating various H-phosphonic acid diesters with a hydroxyalkylcarbamate mixture [87,88] yielded 3-ethyl-2-hydroxy-2-oxo-l,4,2-oxazaphosphorinane 1, which is water--soluble and hydrolytically stable. 

It has been established that silicon-containing phosphonic acid diesters having the general fonnula have fungicidal and bactericidal properties [8], Fungicide products developed on... 

Internal salts of H-phosphonic acid diesters with the general formula given below possess plant preservative properties against pathogenesis caused by fungicides [12]. 

Chiral phosphonous acid diester induces the kinetic resolution of racemic a-substituted y-unsaturated carboxylic acids through asymmetric protolac-tonization (Scheme 53) (130L2838). Dinamic kinetic resolution with Candida antartica lipase B and the ruthenium catalyst [RuCl(CO)2(T -C5Ph5)] of several homoallylic alcohols is applied in the key step to the synthesis of enantiomericaUy pure 5,6-dihydro-2ff-pyran-2-ones ( [13CEJ13859]). 

---