Phosphoryl phenoxide

Phosphoryl Phenoxides and Related Compounds 2.8.2.6 Vinyl Phosphates and Related Compounds... 

The rate of reaction of phosphorus oxychloride with phenols to produce triaryl phosphates is increased by the addition of quaternary ammonium salts and the reaction temperature can be reduced without loss of overall yield [1,2]. The analogous reaction between phenoxide anions and thiophosphoryl chloride produces aryl phosphoro-dichloridothoates [3]. As with the acylation of enolizable (3-dicarbonyl compounds (3.3.12), phosphorylation leads to the predominant formation of the E-O-phos-phoryiated derivatives [4,5]. 

Recently interest has been shown in studies of the biochemical processes, which include the action of enzymes with vanadium-containing centers (like those of serine or tyrosine) that catalyze or inhibiting the redox and phosphorylation reactions, and the alkoxides were investigated as the structural models for the latter [1319, 424], A bimetallic phenoxide of vanadium (II, HI) was found to be an efficient reducive agent for molecular nitrogen in the methanol solutions [1034],... 

Phosphorylation of alcohols by the reagents (9 R=Oalkyl) in aprotic solvents is catalysed by acetate ion, probably through penta- and hexa-co-ordinate intermediates (Scheme 1) that by the corresponding aryl esters is catalysed by phenoxide... 

Phosphate esters are produced by reaction of phosphoryl chloride with phenols or alcohols, or, less commonly, sodium phenoxides/alkoxides, as Reaction (2.12) ... 

A related procedure giving a 90% yield has been described in which phosphorus oxychloride in chloroform was added to a stirred paste of chloroform, water and sodium phenoxide containing a catalytic quantity of polyethyleneglycol 400 (ref.36). L-Tyrosine has been phosphorylated quantitatively by addition to a stirred mixture of phosphorus pentoxide and 85% orthophosphoric acid followed by heating at 80°C for 24 hours, after which water was introduced, the mixture was cooled, diluted with n-butanol and kept at 0°C for 3 hours to precipitate the product (ref.37). 

A study of the reaction of phenylethynyl halides with methoxide anion revealed a complex addition-elimination mechanism for this substitution. Such reactions require application of DMSO as a solvent and afford alkynyl ethers only in 42-46% yield. Reactions of phosphorylated chloroacetylenes 74 with alkoxide anions are even less selective and afford products of nucleophilic addition to the triple bond as major products. However, analogous reaction of 74 with phenoxide anion gives phenoxyacetylenes 75 in moderate yield (equation 46). ... 

Triaiyl phosphates are prepared by phosphorylation of alkyl phenols without phosphorylation catalyst. This simplifies purification of the plasticizer by eliminating the need to withdraw the pirrified product as a distillate. Mixed alkyl diaiyl esters are produced in the presence of a catalytic amoimt of an alkali metal phenoxide. The plasticizer needs to be separated by distillation. Figure 2.39 shows the distillation process of pmifi-cation of triaryl phosphates. A crude triaryl phosphate ester reaction mixtrrre is passed... 

Phenols have been phosphorylated under phase transfer conditions in the presence of a nucleophilic catalyst [31, 32]. The reaction of 4-nitrophenol with dimeth-oxythiophosphoryl chloride is ordinarily slow and leads to a mixture of the desired methyl parathion and hydrolysis products. Addition of N-methylimidazole enhanced the rate but the best results were obtained when both the imidazole and a quaternary ammonium salt (TBAB) were used at the same time. The co-catalysis was accounted for in terms of nucleophilic activation of the acylating agent by imidazole and solubilization of the phenoxide by ion pairing with the quaternary ion. The overall transformation is formulated in equation 6.13. 

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