Trivalent phosphoric acid esters

The Arbuzov reaction,also called the Michaelis-Arbuzov reaction, allows for the synthesis of pentavalent alkyl phosphoric acid esters 4 from trivalent phosphoric acid esters 1 (Z,Z = R,OR) by treatment with alkyl halides 2. 

Examples of the synthesis of phosphite and phosphate esters of sugars are included in a review on trivalent phosphorous acids (Scheme 5). The synthesis of an oxyphosphorane has also been reported (Scheme 6). A strategy for regioselective phosphorylation of aldoses in aqueous solution involves reversible attachment of activated diamidophosphate (DAP). The carbonyl addition prod-... 

The intracellular and plasma membranes have a complex structure. The main components of a membrane are lipids (or phospholipids) and different proteins. Lipids are fatlike substances representing the esters of one di- or trivalent alcohol and two aliphatic fatty acid molecules (with 14 to 24 carbon atoms). In phospholipids, phosphoric acid residues, -0-P0(0 )-O-, are located close to the ester links, -C0-0-. The lipid or phospholipid molecules have the form of a compact polar head (the ester and phosphate groups) and two parallel, long nonpolar tails (the hydrocarbon chains of the fatty acids). The polar head is hydrophihc and readily interacts with water the hydrocarbon tails to the... 

Act to decompose hydroperoxides into stable molecules such as alcohols and ethers, before they can react with light to form free radicals. Main chemical classes are trivalent phosphorous compounds and thio-synergists (esters of thiodipropionic acid). Sulfur-based organic antioxidants decompose hydroperoxides by non-radical reactions. Typical peroxide decomposers are Irgafos 168, Ultranox 626, Irganox PS 800 and others. 

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],... 

Mitsunobu, O., Yamada, M., Mukaiyama, T. Preparation of esters of phosphoric acid by the reaction of trivalent phosphorus compounds with diethyl azodicarboxylate in the presence of alcohols. Bull. Chem. Soc. Jpn. 1967,40, 935-939. 

Some trivalent pyramidal molecules exist in tautomeric equilibrium with tetrahedral forms. Phosphorous acid, for example, may be written as (3.37). This compound exists in tetrahedral form in the solid state or in aqueous solution, although in many of its reactions it behaves as a molecule containing trivalent P. Derivatives obtained by replacing the hydrogen by varions atoms or groups R, can usually be isolated only in one form, depending on the nature of R. Tri-esters with 3 H atoms replaced, exist only in pyramidal form (Chapter 6.8). 

Phosphate fas- fat [F, fr. acide phosphori-qwe phosphoric acid] (1795) n. (1) A salt or ester of a phosphoric acid. (2) The trivalent anion P04 derived from phosphoric acid H3PO4. (3) An organic compound of phosphoric acid in which the acid group is bound to nitrogen or a carboxyl group in a way that permits useful energy to be released. 

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