Phosphonic acid derivatives

Synthesis of a water-soluble, phosphonic acid derivatized, polythiophene, poly(3-(3 -thienyloxy)propanephosphonate) has been reported by Viinikanoja et al. [55]. The polymerizations of both 3-(3 -thienyloxy) propanephosphonic acid and its sodium salt were unsuccessful however an ethyl ester form was electropolymerized in 0.1 M lithium perchlorate/acetonitrilerdichloromethane (1 1) at 1.8 V vs sodium SCE. 

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Because fatty alcohols can easily be converted to the corresponding chlorides or bromides, they are a useful starting material for surface-active phosphonic acid derivatives. A variety of n-alkoxymethylphosphonic acids possessing surface-active properties were synthesized from fatty alcohols having an even number of carbon atoms (Cl2-C18) [98] see Eqs. (34)-(36). 

Additionally, the sequestering ability of polyphosphoric acid and phosphonic acid derivatives as well is a valuable property for their use as dispersants. The main task of dispersants is to suspend solid particles in water or organic solvents and avoid their coalescence and precipitation. This complex plays an important role in many processes and as a result dispersants are used in many technical fields. 

Other cyclizations at phosphorus have been observed when certain phosphinates were used in the acid-catalyzed Mannich reaction. As observed previously with various phosphonous acid derivatives, reaction of aliphatic phosphinic acids with primary amines favored the formation of 2 1 adducts (73). Thus, glycine and other a-amino acids reacted under the typical conditions with excess formaldehyde and alkyl phosphonous acids to give the bis-phosphinylmethyl adducts 125. 

The acid strengths of a series of phosphonic acid derivatives in a variety of solvents have also been used to estimate Hammett constants. In contrast to carboxylic acids, the phosphonic acids are stronger in ketonic solvents than in hydroxylic solvents, which may be attributed to the dissociation of phosphonic acids without the necessity to disrupt the dimeric nature of the acid (see Scheme 3). 

Phosphonic acid derivatives are also well represented. 

Redmore, D., Phosphorus derivatives of nitrogen heterocycles. 2. Pyridine-phosphonic acid derivatives, /. Org. Chem., 35, 4114, 1970. 

Fluorinated phosphinic and phosphonic acid derivatives Perfluoro derivatives of alkyl phosphonic acid CnF2n+1-P(0)(0H)2 and alkyl phosphinic acid CnF2n+i(CmF2m+1)-P(0)0H (n = m or n m) shown with their general structural formulae in Fig. 2.11.29(1) and (II) were examined by negative ESI- and APCI-FIA-MS. These anionic surfactant compounds contained perfluoro alkyl chains [2,22,25]. By analogy with their behaviour in the TSI-FIA-MS(—) process [25], the phosphonic acid formed [M — H] ions at m/z 399 and 499... 

Phosphonic and Phosphinic Acids and their Derivatives.—Further fundamental information on important reactions for preparing phosphonic acid derivatives has... 

In their attempts to prepare aminomethanebis- and tris-phosphonic acid derivatives, Gross et a/.60 have observed the same phenomena. Both groups conclude that... 

If desired, aminoalkylphosphinic acids may be readily oxidized to the phosphonic acid derivatives.[56,63] In fact, some care needs to be taken to exclude air when working with or storing phosphinic acids to prevent this oxidation. 

Compounds containing phosphorus can be both valuable synthetic intermediates and target compounds of solid-phase synthesis. Important synthetic intermediates include phosphonium salts and phosphorus ylides, which are key intermediates in carbonyl olefinations. Their preparation is discussed in Section 5.2.2.1. The preparation of oligonucleotides, these being the most important phosphorus-containing target molecules in solid-phase synthesis, is considered in Section 16.2. In this chapter, the preparation of phosphines, phosphonic acid derivatives, and phosphinic acid derivatives is discussed. 

Phosphonic Acid Derivatives. Very important in this category of proprietary compounds are Trichlorfnn (C hlorophos, Dipterex. Dyloxt and Trichloronatc. 

A more generalized structure (XI) takes into account phosphonic acid derivatives such as Trichlorfon (III) ... 

Phosphinic acid derivatives, Phosphonic acid derivatives, Phosphoric acid derivatives... 

Stable compounds which resemble the transition-state structure of a substrate in an enzymatic reaction are expected to behave as potent reversible inhibitors (1 ). Based on the X-ray crystallographic structure of the active site of carboxypeptidase A (CPA) (2), a mechanism was proposed in which a water molecule adds directly to the scissile carbonyl group of the substrate to give the tetrahedral intermediate 1, which collapses to products (3). We proposed to mimic this tetrahedral intermediate, similar to the transition state, with the stable tetrahedral phosphonic acid derivatives 2,... 

Hydrophilic surface active agents containing C1-C4 phosphoric acid derivatives provide limited benefits because of their short aliphatic chain. To address this concern, hydrophilic phosphonic acid derivative containing an oligomeric ethylene glycol component has been prepared. 

The discovery of the statin mevalonic acid synthesis inhibitors focused new attention on control of blood lipid levels as a measure to stave off heart disease. A number of compounds have been found that treat elevated lipid levels by other diverse mechanisms. The phosphonic acid derivative ibrolipim (9) is believed to lower those levels by accelerating fatty acid oxidation. The phosphoms-containing starting material 7 can in principle be obtained by the Arbuzov reaction of a protected from of p-bromomethylbenzoic acid (6) with triethyl phosphate. Removal of the protecting group and conversion of the acid to an acyl chloride then affords 7. Condensation of this intermediate with substituted aniline 8 leads to the hypolipidemic agent (9). ... 

In other developments, Lecat and Devaud ° have proposed an electrochemical reduction (Scheme 4) to recover triphenylphosphine from triphenylphosphine oxide produced, for example, in the Wittig reaction. Yields of up to 86% were obtained. Engel and Chakrabarty have reduced phosphoric and phosphonic chlorides to the corresponding monobasic phosphorous and phosphonous acid derivatives (equations 23 and 24), using NaBH4 in refluxing dioxane. Triphenylphosphine oxide is reportedly reduced to triphenylphosphine in 75% yield by the electron-transfer system Smh-THF-HMPA, at 65 °C. 

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