Alcohols, phosphorylation reactions

It s this ability to drive otherwise unfavorable phosphorylation reactions that makes ATP so useful. The resultant phosphates are much more reactive as leaving groups in nucleophilic substitutions and eliminations than the corresponding alcohols they re derived from and are therefore more likely to be chemically useful. 

Clear, surface-active phosphate ester compositions were prepared by heating 1 mol P4O,0 with 2-4.5 mol of a linear or branched chain C6, 8 saturated alcohol, a C4 20 mono- or dialkylphenol, or a 2- to 14-mol ethylene oxide adduct of one of these alcohols or alkylphenols at 25-110°C, and hydrolyzing the reaction product at 60-110°C with 0.5-3.0% H20. The hydrolyzed mixture had a lower Klett color value than the phosphorylation reaction mixture [21]. 

The development of monoalkyl phosphate as a low skin irritating anionic surfactant is accented in a review with 30 references on monoalkyl phosphate salts, including surface-active properties, cutaneous effects, and applications to paste and liquid-type skin cleansers, and also phosphorylation reactions from the viewpoint of industrial production [26]. Amine salts of acrylate ester polymers, which are physiologically acceptable and useful as surfactants, are prepared by transesterification of alkyl acrylate polymers with 4-morpholinethanol or the alkanolamines and fatty alcohols or alkoxylated alkylphenols, and neutralizing with carboxylic or phosphoric acid. The polymer salt was used as an emulsifying agent for oils and waxes [70]. Preparation of pharmaceutical liposomes with surfactants derived from phosphoric acid is described in [279]. Lipid bilayer vesicles comprise an anionic or zwitterionic surfactant which when dispersed in H20 at a temperature above the phase transition temperature is in a micellar phase and a second lipid which is a single-chain fatty acid, fatty acid ester, or fatty alcohol which is in an emulsion phase, and cholesterol or a derivative. 

Full details on the phosphorylation of water and alcohols by 4-nitrophenyl dihydrogen phosphate and the NfC H ) - and N(CH3) -salts of its mono- and dianion have been published 146>. Phosphoryl group transfer from the monoanion and dianion is thought to proceed via the monomeric POf ion. Addition of the sterically unhindered amine quinuclidine to an acetonitrile solution containing the phosphate monoanion and tert-butanol produces t-butyl phosphate at a faster rate than does the addition of the more hindered diisopropylethylamine. This nucleophilic catalysis of the phosphorylation reaction is also explained by the intermediacy of the POf ion. 

DNA is precipitated from aqueous solutions by ethanol or isopropanol in the presence of salt. The amount of alcohol and salt depends on the type of salt that one wishes to use (Table 6.2). The type of salt used depends largely on downstream applications for which the DNA is to be used. For example, precipitation in the presence of ammonium acetate removes small molecules such as nucleotides, and the DNA can be used for many enzymatic reactions. On the other hand, the phosphorylating enzyme, T4 kinase, is inhibited by ammonium ions, and unless DNA is reprecipitated in the presence of salts other than ammonium acetate, the phosphorylation reaction may be inhibited. For most routine purposes, alcohol precipitation of DNA with sodium acetate is preferred over sodium chloride because of the higher solubility of the acetate salt in ethanol. Selection of isopropanol or ethanol is more of a convenience than a rule. Although isopropanol precipitation requires an equal volume of isopropanol for the precipitation of DNA, that with ethanol requires 2 volumes and hence can increase the total volume... 

Givens58 and Pirrung59 used photolabile 3 3 -dimethoxybenzoin esters for the protection of phosphotriesters. A complication attending the use of racemic 3 5 dimethoxybenzoin is the generation of four diastereoisomers if the phosphate is chiral. An asymmetric synthesis of 3, 5 -dimethoxybenzoin 303 [Scheme 7.30] via the 0-trimethylsilyl-3,5-dimethoxybenzaldehyde cyanohydrin 303 minimises the number of diastereoisomers created in the phosphorylation of chiral alcohols. Thus reaction of 303 with 2 - cyanoethoxy)(NPNf-diisopropy amino)-chlorophosphine afforded the phosphoramidite 30.4 which then reacted with Boc-Ser-OMe to give the two diastereoisomeric phosphotriesters 303, Photode-... 

C-O bond and forming a carboxylic ester (Section 21.5), phosphoric anhydrides react with alcohols by breaking a P-O bond and forming a phosphate ester, ROPO ". Note that phosphorylation reactions with ATP generally require the presence of a divalent metal cation in the enzyme, usually Mg ", to form a Lewis acid/base complex with the phosphate oxygen atoms and neutralize some negative charge. 

Scheme 14 shows a proposed application in which PC is transformed into phosphatidylsolketal (PSK). This compound is hydrolyzed by PLCpc forming the OP corresponding to the alcohol acceptor in the first enzymatic reaction. The result of the sequential use of the two enzymes, one in transesterification and the second in hydrolysis, corresponds to the net phosphorylation reaction. The reaction can be of very wide applicability if the hypothesis is verified that both... 

Polyfluoroalkyl phosphorodichloridates and bis(poly-fluoroalkyl) phosphorochloridates have been prepared from the corresponding alcohols. The reactions between polychloro-1-nitrosoethanes and phosphorus(III) chlorides have provided the phosphoryl chlorides (3) and (4) whilst the same procedure... 

Phosphorylation reaction with alcohols 5, 3.3.5.5.2 HjPSi HjSiPH,... 

The one-pot radical fragmentation-phosphorylation reaction of a-amino acids or 3-amino alcohols (e.g., 619) affords a-amino phosphonates 620 in good yields (Scheme 3.243). This reaction has been applied to the synthesis of biologically active phosphonates [651]. 

The conversion of mevalonate (1) to isopentenyl pyrophosphate (IPP) (4) involves two consecutive phosphorylations at position 5 by successive action of mevalonate kinase (EC 2.7.4.2) and a decarboxylation and dehydration of the tertiary alcohol group by mevalonate 5-pyrophosphate decarboxylase (EC 4.1.1.33) (Fig. 18.4) (Crotean Johnson, 1985 Gershenzon and Croteau, 1990). One mole of ATP is required for each phosphorylation reaction. Mevalonate kinase converts mevalonic acid to (5/ )-phosphomevalonate (5). The second phosphorylation is catalyzed by phospho-mevalonate kinase. The subsequent decarboxylation and dehydration is mediated by the enzyme mevalonate diphosphate decarboxylase (di- or pyrophosphomevalonate decarboxylase EC 4,1.1.3.3) this enzyme requires Mg " or Mn + and ATP for activity (Beale and MacMillan, 1988 Harrison, 1988). All three of these enzymes are found in a number of plants. 

Glucose-l-phosphoric add will undergo tiansglucosylation with an alcohol in reaction (5.352). The reverse of this is phosphorylation (Chapter 11). This type of reversible reaction, of great importance... 

Phosphorylation is a process involved in many cellular pathways such as activation or deactivation of enzymes. An extensive study of enantioselective phosphorylation reactions was reported by Miller and coworkers using several 7i-(Me)-histidine containing peptides. The proposed catalytic cycle involves the generation of an high energy phospho-imidazoUum ion and its reaction with the alcohol substrate in a site-specific manner. Following this mechanism, regio- and enantiopure phosphorylated alcohols can be prepared (Scheme 5.8). 

The procedure described is essentially that of Shioiri and Yamada. Diphenyl phosphorazidate is a useful and versatile reagent in organic synthesis. It has been used for racemlzatlon-free peptide syntheses, thiol ester synthesis, a modified Curtius reaction, an esterification of a-substituted carboxylic acld, formation of diketoplperazines, alkyl azide synthesis, phosphorylation of alcohols and amines,and polymerization of amino acids and peptides. - Furthermore, diphenyl phosphorazidate acts as a nitrene source and as a 1,3-dipole.An example in the ring contraction of cyclic ketones to form cycloalkanecarboxylic acids is presented in the next procedure, this volume. 

Primary alcohols may be phosphorylated by use of the Mitsunobu reaction (Ph, , DEAD, HBF4, Pyr). Of several salts examined, the potassium salt of the phosphate was the best. 

Product Acceptors. Many enzyme assays use acceptors, as for instance 2-ethylaminoethanol and other aminated alcohols iihich act as acceptors for the phosphoryl product of the reaction catalyzed by alkaline phosphatase (25) (Fig. 4). Hydroxylamine can act as an acceptor for the hydroxyacetone produced by eno-lase and semicarbazide can act as an acceptor for the pyruvate produced by LD. It is necessary to optimize the concentration of such an acceptor before using it routinely as often what may be a theoretically desirable acceptor is in practice superfluous. 

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