Phosphorus compounds phosphorylation

Phosphorus. Eighty-five percent of the phosphoms, the second most abundant element in the human body, is located in bones and teeth (24,35). Whereas there is constant exchange of calcium and phosphoms between bones and blood, there is very Httle turnover in teeth (25). The Ca P ratio in bones is constant at about 2 1. Every tissue and cell contains phosphoms, generally as a salt or ester of mono-, di-, or tribasic phosphoric acid, as phosphoHpids, or as phosphorylated sugars (24). Phosphoms is involved in a large number and wide variety of metaboHc functions. Examples are carbohydrate metaboHsm (36,37), adenosine triphosphate (ATP) from fatty acid metaboHsm (38), and oxidative phosphorylation (36,39). Common food sources rich in phosphoms are Hsted in Table 5 (see also Phosphorus compounds). 

In the course of the tempestuous development of organophosphorus chemistry, interest has only recently been focused on compounds of formally quinquevalent phosphorus having coordination number 3, such as 1, 2, or 3, although one of the other species of this kind has long been postulated as reactive intermediate of solvolysis of phosphorylation reactions. Definite evidence of even proof of the existence of such coordinatively unsaturated phosphorus compounds, however, has been obtained only recently in mechanistic studies, by trapping reactions with suitable cycloaddends, or actually by direct isolation. 

It is possible to speculate on a situation analogous to that shown in fig. 19(6) or fig. 20(a) for certain anticholinesterases such as T.E.P.P. or p-nitrophenyl esters (fig. 21). Here a H 0 bonding may perhaps be envisaged in place of the H F bonding. Whatever the precise mechanism of attack by the phosphorus compound on the enzyme, the fact is that the latter is phos-phorylated in contradistinction to normal acetylation. Whereas the acetyl group is readily removed by hydrolysis under normal conditions, the phosphoryl group is usually firmly attached. 

Further use has been made of the reaction of disulphides with tervalent phosphorus compounds in phosphorylation reactions, e.g. in the synthesis of (57).68... 

Phosphoryl radicals [10, 18, 38-42] tend to add to double bonds. Owing to the exceptionally high constants of hyperfine coupling of the unpaired electron with the phosphorus nucleus, phosphoryl radicals can be utilized as paramagnetic reporters [10]. Phosphoryl radicals have been prepared by photolysis of diphosphoryl mercury compounds (Scheme 6.5). 

The irreversible inhibition of cholinesterases by organic phosphorus compounds and demonstration of the fact that a phosphoryl residue of the form (ltO)2P+ combines with the enzyme opened a new approach to the... 

The second group of the reactions resulting in the formation of phosphorylated ketenes is based on the specific properties of trivalent phosphorus compounds (2 -- ).The Phosphines bearing an activated hydrogen atom in oC -position readily react with carbon tetrahalides... 

An important aspect of this paper is the demonstrated facile formation of the P-O-P system by nucleophilic attack of phosphoryl oxygen on the four-coordinated phosphorus center. This result confirms the reaction schemes proposed earlier for a number of reactions, important from the synthetic point of view of organo-phosphorus compounds (9-13) and polymers (1 A). 

Zwitterionic cr-Complexes Their Role as Intermediates in Phosphorylation of Aromatics by Phosphorus Compounds... 

The extraction ability of neutral organophosphorus compounds closely related to the charge density of phosphoryl oxygen (qo) and phosphorus atom(qp). It was found that the distribution ratio of cerium enhanced as the qo and qp values was increased. Meanwhile a linear free energy relationship exists between the 2A.i values and the Kabachnik constant for substituents of phosphorus compounds. As estimated by least squares method, an empirical equation v° =-3.84+0.1682Ai was deduced... 

Different OP compounds have structural similarities within classes. The phosphorus compounds have the characteristic phosphoryl bond, P=0. Most OP compounds have a phosphoryl bond or a thiophosphoryl bond (P=S). All OP compounds are esters of phosphorus with varying combinations of oxygen, carbon, sulfur, and nitrogen attached. These are classified as (1) phosphates (2) phos-phonates (3) phosphorothioates (4) phosphorodithioates (5) phosphorothiolates and (6) phosphoramidates. Further, the OP compounds are categorized as (1) aliphatic (2) phenyl and (3) heterocyclic derivatives. The aliphatic are carbon chainlike in structure. TEPP, which was used in agriculture for the first time in 1946, is a member of this group. Others include malathion, trichlorfon, monocrotophos, dimethoate, oxydemetonmethyl, dimethoate, dicrotophos, disulfoton, dichlorvos, mevinphos, methamidophos, and acephate. 

Silane reductions of phosphorus compounds are listed in Table 1. Mono- or dichlorophosphines and phosphoryl compounds react with Ph SiH, e.g. ... 

Arseno-phosphorus compounds have been obtained by treating m-amino-p-hydroxyphenylarsinic acid with phosphoryl chloride in the presence of aqueous sodium hydroxide and subsequently reducing the mixture with sodium hydrosmphite. The compounds arc soluble in dilute sodium carbonate and in hydrochloric acid, their alkaline solutions reducing Fehling s solution and Nessler s and Tollen s reagents. ... 

Pentavalent phosphorus compounds with a suitable leaving group, listed below, serve effectively as phosphorylating agents for some protic substrates such as alcohols, phenols, primary and secondary amines, thiols, phosphates, etc. 

The year s reviews cover phosphorylated indoles, phosphorus-selenium compounds, phosphoryl carbenes, phosphorus-sulphur compounds, and steroid phosphates, as well as the synthesis of phosphorus esters via oxyphosphoranes. A review on phosphonates contains many interesting applications of some of the well-tried syntheses of these as analogues of natural phosphates. ... 

Borowitz and his co-workers have carried out a detailed comparative study of the reactions of phosphinites, phosphonites, and phosphites with -halogenoketones. The balance between keto-phosphorylation and enol-phosphorylation favours the former with increasing oxygen content of the phosphorus compound, higher temperature, more polar solvents, and bromo-rather than chloro-ketones. a -Dibromobiacetyl reacts with two moles of phosphite to give the double Perkow product (43) and no trace of the alternative Arbusov product or of the phosphorane (45). The rate of the first Perkow... 

Phosphorus-containing enamines have been prepared by phosphorylation of N-vinyl substituted tertiary amides, lactams and cyclic imides with phosphorus pentachloride ". Addition of amines to diphosphoryl alkynes has been described. Addition of RR NH [R = H, Ri = Me, cyclohexyl, PhCH2 RR = (CHj) to (Et0)2P(0)C=CP(0K0Et2)2 in CH2CI2 at 25 °C gave 93-100% of (Et0)2P(0)C(NRRi)=CHP(0)(0Et2)2 . Speziale and coworkers have studied the reactions of phosphorus compounds with trichloroacetamides. 

To compare the ability of different compounds to transfer a phosphoryl group, phosphorylation of water was chosen as a standard reaction[17]. The free energy of hydrolysis of a phosphorus compound (AGhydr) is called its phosphorylating potential. Table 13-2 summarizes the phosphorylating potentials of the most important biological compounds (Fig. 13-3) having phosphoryl donor abilities. 

The ester fluorides of phosphoric acid and phosphonic adds were the earliest known examples of biologically active phosphorus compounds. Sarin (2) and soman (3), previously mentioned, did not attain practical importance because of their high toxicity, but they were the starting point for the development of other derivatives more suitable for agricultural purposes. Within this framework Schrader developed N,N,N, N -tetramethyl phosphorodiamidofluoridate (14), which is used under the name dimefox. It is produced by the reaction of phosphoryl chloride with dimethylamine and the subsequent interaction of the phosphoro-chloridate formed with sodium fluoride (Schrader, 1947). 

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