Phosphonic acid esters phosphites

Most common is the preparation of alkyl phosphonic acid esters (phospho-nates) 4 (Z,Z = OR) from phosphorous acid esters (phosphites) 1 (Z,Z = OR). The preparation of phosphinic acid esters (Z = R, Z = OR) from phosphonous acid esters, as well as phosphine oxides (Z,Z = R) from phosphinous acid esters is also possible. 

Dibutyl phosphite reacting with 2-butenoic acid ethyl ester yields the corresponding phosphonic acid ester see Eq. (65). 

Obrycki. R.. and Griffin. C.E.. Phosphonic acids esters. Part 19. Syntheses of substimted phenyl- and arylphosphonates by the photoinitiated arylation of trialkyl phosphites, J. Org. Chem., 33, 632, 1968. Engel. R.. Synthesis of Carbon-Phosphorus Bonds, CRC Press, Boca Raton, 1988, p. 137. 

Pudovik, A.N., and Gazizov, T.K., Thennal isomerization of diethyl acetyl phosphite and reactions of dialkyl acetyl phosphites with a-oxo phosphonic acid esters, Zh. Obshch. Khim., 38, 140, 1968 J. Gen. Chem. USSR (Engl. Transl.). 38. 139. 1968. 

The formation of phosphate esters from amine-catalyzed reactions between dialkyl phosphites and ketones often accompanies the expected production of (a-hydroxyalkyl)phosphonic acid esters (see Section 2.1). It is also known that under... 

Phosphonic acid esters from phosphites Arbusov rearrangement... 

Equation 28 represents the formation of oxoalkyl phosphonic acid esters (488 R = OR) or phosphinic esters (488 R = alkyl or aryl) from phosphite or phosphonite esters and appropriate halogen-containing ketones ( > 1) or acyl halides (n = 0), and supplements the formation of the phosphonoylated or phosphinoylated alkanoic acids through reactions 21 and 22 in the previous section. 

Sodium alcohol Phosphonic acid esters from dialkyl phosphites and ethylene derivs. 

R2HP03 0 II H—P—OR phosphonate ester (phosphite) phosphonic acid, mono- and diesters exist... 

R3P03 RO—P—OR 1 OR triphosphite ester (phosphite) hypothetical phosphorous acid, P(0H)2 stmcture is isomeric with phosphonates... 

Trialkyl esters of phosphonic acid exist ia two structurally isomeric forms. The trialkylphosphites, P(OR)2, are isomers of the more stable phosphonates, 0=PR(0R)2, and the former may be rearranged to resemble the latter with catalytic quantities of alkylating agent. The dialkyl alkylphosphonates are used as flame retardants, plasticizers, and iatermediates. The MichaeUs-Arbusov reaction may be used for a variety of compound types, including mono- and diphosphites having aryl as weU as alkyl substituents (22). Triaryl phosphites do not readily undergo the MichaeUs-Arbusov reaction, although there are a few special cases. 

Although the phosphorous acid esters are often referred to as such, they are not true phosphites [72]. To be more precise, they exist almost exclusively in the phosphonate form of pentavalent phosphorus, as shown in structures (5) and (6) ... 

Various cyclic phosphonate esters 36 and 37 have been described previously as products from the HHT reaction of 25 with the appropriate cyclic phosphite. A complementary method has also been developed from the V-protected phosphonyl chloride 84, which was readily prepared from the corresponding phosphonic acid 83. Subsequent reaction of 84 with the appropriate diol produced the cyclic phosphonate esters 85 (63). Higher homologs of 85 have also been prepared from the analogous propane or butane diols. 

Olefination Reactions Involving Phosphonate Anions. An important complement to the Wittig reaction involves the reaction of phosphonate carbanions with carbonyl compounds 253 The alkylphosphonic acid esters are made by the reaction of an alkyl halide, preferably primary, with a phosphite ester. Phosphonate carbanions are generated by treating alkylphosphonate esters with a base such as sodium hydride, n-butyllithium, or sodium ethoxide. Alumina coated with KF or KOH has also found use as the base.254... 

Several methods for the preparation of the parent compound in this system, tris(trimethylsilyl)phosphite, have been reported.114 118 The application of this and related reagents in reaction with alkyl halides has been reported and used for the preparation of a variety of phosphonic acid analogues of phospholipids.114119-124 Interestingly, alkyl chlorides appear to be more reactive with the silyl reagents than do alkyl iodides, a reversal of the normally observed trend with alkyl esters of the phosphorus acids. (The particular use of silyl phosphorus reagents for the synthesis of biologically significant compounds has... 

A series of 1-aminoalkanediphosphonic acids has been reported by the treatment of the N-phenylthiourea derivatives of a>-diethoxyphos-phinoylaldehydes with triphenyl phosphite.343 This constitutes an approach toward the analogues of aspartic and glutamic acid in which both carboxylate sites have been replaced by phosphonic acid functions. A similar approach has also been reported to be of use for the preparation of (diphenyl ester) phosphonate analogues of ornithine, lysine, and homolysine.344345... 

Diethyl phosphite Phosphonic acid, diethyl ester (762-04-9), 75, 23... 

The addition of finely dispersed solid particles improves the IR absorption of the polymer and positively influences blowing of the preforms. Such solid particles can be obtained by the reduction of Sb3+ to metallic antimony during polycondensation by the addition of trivalent phosphorous compounds such as phosphonic acid or its esters (phosphites). However, only a slight improvement in properties could be achieved by this approach [35],... 

Pudovik AN (1952) Addition of dialkyl phosphites to imines. New method of synthesis of esters of amino phosphonic acids. Dokl Akad Nauk SSSR 83 865-868... 

An unusual reaction of electron-deficient acetylenes (usually DMAD is used) and triarylphosphines or -phosphites with Cjq leads to methanofullerenes that bear an a-ylidic ester (Scheme 3.11). Selective hydrolysis of the phosphite ylides yields phosphonate esters, phosphine oxides or phosphonic acids [49-51]. 

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