Phosphorus acid esters

The reaction of the end OH group of the oleylamide of A-hydroxyethyl-diethylentriamine with phosphorus trichloride and water in the presence of carbon tetrachloride yielding a primary phosphorus acid ester [63], as is shown in Eq. (74), is a typical reaction of this type. 

Phosphotriesterase from P. diminuta (PTE) was found to exhibit high hydrolytic activity towards various types of tetracoordinated phosphorus acid esters. Apart from the phosphonothionate 92, phosphoric acid triesters 94 (Equation 45), °" benzenephosphonic acid diester 95 (Equation 46) ° and methyl-phenylphosphinic acid ester 96 (Equation 47) were also stereoselectively hydrolysed under kinetic resolution conditions. Of course, in the case of the latter three kinds of substrates, half of the reacting ester was irreversibly lost due to the formation of achiral phosphorus acids. 

Mikolajczyk, M., Optically active trivalent phosphorus acid esters synthesis, chirality at phosphorus and some transformations, Pure Appl. Chem., 52, 959, 1980. 

Trivalent phosphorus compounds are capable of removing vicinal halogens from organic compounds and thus represent a useful alternative method to dehalogenations with metals. Phosphorus agents employed include triphenylphosphane,112 and phosphorus acid esters (triethyl phosphite154 and tributyl phosphite155) and amides [tris(dimethylamino)phosphane 56 and tris(diethylamino)phosphane 57,158]. 

Plasticizers include the esters of a few aliphatic and aromatic mono and dicarboxylic acids, aliphatic and aromatic phosphorus acid esters, ethers, alcohols, ketones, amines, amides, and non-polar and chlorinated hydrocarbons. These additives are used in various mixtures. For their separation and qualitative detection, thin-layer chromatography (TLC) is preferred. Usually Kieselgur plates, 0.25 mm thick, activated at 110°C for 30 min, in the saturated vapor are used. Methylene chloride and mixtures of diisopropyl ether/petether at temperatures between 40 to 60°C have been successfully used as the mobile phase. Refer to Table 1. 

Ketelaar, J.A.A., Gersmann, H.R. (1958) Chemical studies on insecticides. VI. The rate of hydrolysis of some phosphorus acid esters. Rev. Trav. Chim. 77, 973-981. 

Attack on Unsaturated Carbon.- A versatile route to phosphinic acids (15) is the 1,4-addition of bis(trimethylsilyl) phosphonite (16) to a,p-unsaturated esters.The pyrophoric (16) was prepared in s/fu from triethylammonium phosphinate silylation and 1,4-addition can be repeated to give (17), or performed in one step if symmetrical phosphinic acids (17) are wanted. Tervalent phosphorus acid esters (18) react with dialkyl acetylenedicarboxylates in the presence of carbon dioxide to give 1,2-oxa-phospholenes (19) these reacted further with an excess of the phosphorus reagent to give different ylids, (20) or (21), dependant on the number of methoxy groups in (18). 

Abramov nucleophilic addition of various phosphorus acid esters to nucleoside aldehyde derivatives yielded the phosphonate-based iso-polar, non-iso-steric 5 -nucleotide analogues (28) containing a geminal hydroxy phosphonate moiety on the 5 -carbon of the pentofuranose ring. The enantiomerically pure D- and l- 2, 3, 5 -trideoxy-4 -[(ethoxyphosphoryl) difluoromethyl] thymidine analogues(29) have been synthesized from (i 5)-( )-2-methyl-5-(4-methyl-phenyl-sulfinyl)pent-2-ene and ethyl 2-(diethoxyphosphoryl)-2,2-difluoro-acetate in 45% overall yield over seven steps. ... 

Tervalent phosphorus acid esters, and triphenylphosphine, attack 2-bromothiazole (34) at bromine in alcoholic solvents to give thiazole and the oxidised phosphorus compounds. A similar attack of tris(diethylamino)phosphine on the bromine atom of bromopentafluorobenzene was used to prepare a series of main-group-four pentafluorophenyl derivatives, e.g. (35). A full paper has appeared on the fluoridation of trimethylsilyl phosphites, or phosphoramidites, with sulphury chloride fluoride. The mild conditions allowed the preparation of sensitive nucleoside derivatives, e.g. (36) and (37). 

While cyclizing amidation of amino A 5 -phosphorus acid/esters (e.g., 23) remains a powerful method, there have been now examples of cyclizing amidation of azido A fi -phosphorus esters (e.g., 24) (Scheme 18) <2001SL473, 2004AGE3471>. 

Table 15,1 The results of quantitative treatment of kinetic data for nucleophilic substitution in phosphorus acid esters in terms of equation i5.r... 

L. Ya. Zakharova, A. R. Ibragimova, F. G. Valeeva, V. M. Zakharov, L. A. Kudryavtseva, A. I. Konovalov, N. L. Zakharchenko, Yu. F. Zuev, Influence of temperature on the reactivity of phosphorus acid esters in reverse micellar systems based on sodium bis(2-ethylhexyl)sulfo-succinate, Russ. Chem. Bull, 2005, 54, 1449-1557. 

Within the last two decades, a number of chemical structures have been proposed as metal deactivators for polyolefins. These include carboxylic acid amides of aromatic mono- and di-carboxylic acids and N-substituted derivatives such as N,N -diphenyloxamide, cyclic amides such as barbituric acid, hydrazones and bishydrazones of aromatic aldehydes such as benzaldehyde and salicylaldehyde or of o-hydroxy-arylketones, hydrazides of aliphatic and aromatic mono- and di-carboxylic acids as well as N-acylated derivatives thereof, bisacylated hydrazine derivatives, polyhydrazides, and phosphorus acid ester of a thiobisphenol. An index of trade names and suppliers of a few commercial metal deactivators is given in Appendix A4. 

Phosphorus acid esters with at least one oxirane substituent [19]... 

Chiral silylphosphite esters have been prepared and silylated triphosphites RSi[OP(OR)2l3 readily complex catechol phosphorus acid esters result from 3,5-t-Bu2-o-benzoquinone... 

The PH wagging vibration is probably involved in medium-to-strong bands in R2-P(=0)-H at 990-965 cm and R2-P(=S)-H at 950-910 cm where R= alkyl or phenyl groups. Phosphorus acid esters (R0)2 - P(=0)—H have a very strong band at 980-960 cm" which is some-... 

Phosphorus acid esters are very well-known antioxidants, mainly for polyolefins, but as mentioned previously, they also find application as PVC stabilizers (see Section 10.2.2). Good examples are tri(nonylphenyl) phosphite (Santowhite TNPP). 

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