Hydrolysis of diphenyl

Poly(methyl 3-(l-oxypyridinyl)siloxane) was synthesized and shown to have catalytic activity in transacylation reactions of carboxylic and phosphoric acid derivatives. 3-(Methyldichlorosilyl)pyridine (1) was made by metallation of 3-bromopyridine with n-BuLi followed by reaction with excess MeSiCl3. 1 was hydrolyzed in aqueous ammonia to give hydroxyl terminated poly(methyl 3-pyridinylsiloxane) (2) which was end-blocked to polymer 3 with (Me3Si)2NH and Me3SiCl. Polymer 3 was N-oxidized with m-ClC6H4C03H to give 4. Species 1-4 were characterized by IR and H NMR spectra. MS of 1 and thermal analysis (DSC and TGA) of 2-4 are discussed. 3-(Trimethylsilyl)-pyridine 1-oxide (6), l,3-dimethyl-l,3-bis-3-(l-oxypyridinyl) disiloxane (7) and 4 were effective catalysts for conversion of benzoyl chloride to benzoic anhydride in CH2Cl2/aqueous NaHCC>3 suspensions and for hydrolysis of diphenyl phosphorochloridate in aqueous NaHCC>3. The latter had a ti/2 of less than 10 min at 23°C. 

Hydrolysis of diphenyl phosphorochloridate (DPPC) in 2.0 M aqueous sodium carbonate is also believed to be a two-phase process. DPPC is quite insoluble in water and forms an insoluble second phase at the concentration employed (i.e. 0.10 M). It seems highly significant that the hydrophobic silicon-substituted pyridine 1-oxides (4,6,7) are much more effective catalysts than hydrophilic 8 and 9. In fact, 4 is clearly the most effective catalyst we have examined for this reaction (ti/2 < 10 min). Since derivatives of phosphoric acids are known to undergo substitution reactions via nucleophilic addition-elimination sequences 1201 (Equation 5), we believe that the initial step in hydrolysis of DPPC occurs in the organic phase. Moreover, the... 

As the Ca2+ concentration is lowered, the rate of the uncatalyzed hydrolysis decreases more rapidly than the catalyzed process, producing an increase in the rate acceleration ratio. For example, as the ratio of Ca2+ to cycloheptaamylose is decreased from 1 1 to 0.33 1, the rate acceleration for the hydrolysis of diphenyl pyrophosphate increases from 4.4 to 27. At lower Ca2+ concentrations, catalysis by the cycloamyloses was described as absolute catalysis since the rate of the spontaneous hydrolysis could not be measured. The term absolute catalysis is misleading, however, since the uncatalyzed rate, no matter how slow, must be finite. 

Diphenylacetic acid has been obtained by the reduction of benzilic acid with hydriodic acid and red phosphorus 1 by the treatment of phenylbromoacetic acid with benzene and zinc dust,2 or with benzene and aluminum chloride 3 by the hydrolysis of diphenylacetonitrile 4 by heating a-diphenyldichloroethyl-ene with alcoholic sodium ethylate 5 by heating benzilic acid 6 from diphenylmethane, mercury diethyl, sodium and carbon dioxide 7 by the oxidation of a,a,5,S-tetraphenyl- 8-butine 8 by the decomposition of some complex derivatives obtained from diphenylketene 9 by the hydrolysis of diphenyl-5,5-hydan-toin 10 by the treatment of diphenylbromoacetic acid with copper 11 by the oxidation of dichlorodiphenylcrotonic acid.12... 

Benzilic acid has been made by the action of potassium hydroxide on benzil, either in concentrated aqueous solution 1 (described first in a paper by M. Bosler and later in papers by H. Klinger and by H. Staudinger) or in alcoholic solution2 (described by J. Liebig, N. Zinin, A. Jena and H. v. Liebig) and either one of these processes furnishes a method for producing benzilic acid cheaply and in large amounts. The other methods by which it may be made are the action of alcoholic potash upon isobenzil 3 the hydrolysis of diphenyl-bromoacetic acid 4 the action of alkalies upon benzoin 5 the action of sodium on benzo-phenone.6... 

Scheme 1 Hydrolysis of diphenyl-carbonate (1) to give 4-nitro-phenol (2), 4-acetamido-phenol and carbon dioxide. The diphenyl-phosphate (4) was used as TSA to mimic the tetrahedral transition state formed during the hydrolysis...

Menger et al. synthesized a Ci4H29-attached copper(II) complex 3 that possessed a remarkable catalytic activity in the hydrolysis of diphenyl 4-nitrophenyl phosphate (DNP) and the nerve gas Soman (see Scheme 2) [21], When 3 was used in great excess (ca. 1.5 mM, which is more than the critical micelle concentration of 0.18 mM), the hydrolysis of DNP (0.04 mM) was more than 200 times faster than with an equivalent concentration of the nonmicellar homo-logue, the Cu2+-tetramethylethylenediamine complex 9, at 25°C and pH 6 (Scheme 4). The DNP half-life is calculated to be 17 sec with excess 1.5 mM 3 at 25°C and pH 6. The possible reasons for the rate acceleration with 3 were the enhanced electrophilicity of the micellized copper(II) ion or the acidity of the Cu2+-bound water and an intramolecular type of reaction due to the micellar formation. On the basis of the pH(6-8.3)-insensitive rates, Cu2+-OH species 3b (generated with pK3 < 6) was postulated to be an active catalytic species. In this study, the stability constants for 3 and 9 and the thermodynamic pvalue of the Cu2+-bound water for 3a —> 3b + H+ were not measured, probably because of complexity and/or instability of the metal compounds. Therefore, the question remains as to whether or not 3b is the only active species in the reaction solution. Despite the lack of a detailed reaction mechanism, 3 seems to be the best detoxifying reagent documented in the literature. 

Recently, Bunton et al. synthesized the Ci6H33-attached triamine copper(II) complex 8b [26], which promoted the hydrolysis of diphenyl 4-nitrophenyl phosphate (DNP) at alkaline pH. The catalytic activity was almost the same as that for Menger s previously reported comicellar system with 3b. The active species was proposed to be the hydroxide-bound copper(II) complex 8b. The pvalue of the copper(II)-bound water molecule was speculated to be about 8 from the fact that the nonalkylated and tetradecyl homologous copper(II) complexes have a pvalue of 8 (determined by DNP hydrolysis kinetics). Since the micellar metal complex 8b was not fully characterized either in the solid state or in a micellar solution, its hydrolysis mechanism remains to be elucidated. 

Monamidophosphoric Acid, NH2PO(OH)2, has been obtained by several reactions, among which are the hydrolysis of diphenyl amidophosphate by means of alkali, thus... 

Similar to catalytic antibodies, we observed some product inhibition. In the case mentioned, the reaction rate was calculated from the amount of released acid. If the calculation is based on phenol release, the rate enhancement turned out to be nearly doubled. Hydrolysis of carbonates should avoid this difficulty. Therefore, diphenyl phosphate was used as template, and the hydrolysis of diphenyl carbonate was then investigated [13]. Compared to solution an enhancement of 982-fold was obtained and typical Michaelis-Menten kinetics were observed (K ,ax = 0.023 mM/min, = 5.01 mM, = 0.0115/min, kaalK = 2.30/min/M). 

Strikovsky AG, Kasper D, Grun M, Green BS, Hradil J, Wulff G (2000) Catalytic molecularly imprinted polymers using conventional bulk polymerization or suspension polymerization Selective hydrolysis of diphenyl carbonate and diphenyl carbamate. J Am Chem Soc 122 6295... 

Attachment of a cyclodextrin unit to an N-CH3 form of the CR macrocycle (Fig. 39) yielded a zinc complex with only modestly improved effectiveness (k2 = 21.7x 10 2M 1s 1) over the mononuclear system (k2 — (3.80 + 0.05) x 10 2M 1s 1) for the hydrolysis of diphenyl 4-nitrophenyl phosphate under identical conditions.109 This enhancement is proposed to be due to binding of 4-nitrophenolate moiety in the cyclodextrin cavity. 

Several multinuclear zinc complexes that exhibit phosphate diester and triester reactivity have been reported. A binuclear analog of [(CR)Zn]2+ (Fig. 6a) in which two [(CR)Zn]2+ units are linked by an aromatic spacer was found to be 4.4 times more effective in terms of the hydrolysis of diphenyl 4-nitrophenyl phosphate in CH3CN H20 at 25 °C than its mononuclear analog.204... 

In these reactions, hydrolysis of diphenyl and triaryl phosphites to monoaryl phosphites and phenol was coupled by dehydration between carboxylic acids and amines or alcohols to the corresponding amides and esters. Therefore, the reaction can be generalized as a hydrolysis-dehydration reaction (Scheme 2). The concept of the hydrolysis-dehydration reaction using phosphites has been drown to be applicable also to reactions with other phosphorus compounds such as phosphinites, phos-phonites and phosphorates s Aryl esters of these phosphorus compounds are effective as condensing agents in the production of carboxylic amides and esters (from carboxylic acids and amines or alcohols, respectively) whereas alkyl esters are ineffective (Eqs. (1-3)) ... 

Diphenyl phosphate N,N -diethyl(4-vinylphenyl)amidine MMA EDMA MeCN, cyclohexanol+dodecanol or toluene Using transition state analog selective hydrolysis of diphenyl carbonate and diphenyl carbamate bulk and suspension polymerization [174)... 

Breslow and co-workers (64) studied the hydrolysis of diphenyl-4-nitro-phenylphosphate (DPNPP) by the Zn complex of macrocyclc 5 (112). Wooley had studied this complex and found that it catalyzed the hydration... 

Kinetic studies of the aminolysis of bis(Y-phenyl) chlorophosphates ([YCgH40]2 (P=0)C1 Y = H, 4-Me, 4-MeO, 3-MeO) by anilines and deuterated anilines showed that the reaction proceeded via a stepwise mechanism, with rate-determining breakdown of the trigonal bipyramidal intermediate. The effects of solvents and solvent mixtures upon the rates of hydrolysis of diphenyl and bis-(2,4-dichlorophenyl) chlorophosphate showed that there were large sensitivities towards changes in solvent nucleophilicity, consistent with an 5 ivf2(P) process. ... 

To avoid the issne of product inhibition, Wnlff etal. investigated the hydrolysis of carbonates and carbamates, which release prodncts with no significant affinity for the amidine active site. Rate enhancements for the hydrolysis of diphenyl carbonate and diphenyl carbamate were fonnd to be 588 and 1435, respectively, compared to the nncatalyzed reaction. ... 

An associative A2 mechanism is operative for the hydrolysis of diphenyl-phosphinic amide Ph2P(0)NH2 and some analogs in dilute perchloric acid-dioxan, as shown by the retardation of rate produced by the presence of ortho-methyl substituents in the aryl groups... 

Phosphorus-Oxygen-Nitrogen Compounds. The alkaline hydrolysis of diphenyl-amidophosphate occurs by a bimolecular addition of hydroxide ion at phosphorus. 

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