Alkaline Hydrolysis of Diethyl Esters of Alkylphosphonic Acids and Some Chloro-substituted Derivatives.

Aksnes, Gunnar; Songstad, Jon; Juvvik, Paul; Thelin, Hugo; Sjöberg, Berndt; Larsen, Erik

doi:10.3891/acta.chem.scand.19-0893

Cited by 17 publications

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“…When comparing phosphoryl and carbonyl compounds, the steric requirements for approach to a tetrahedral molecule are more exacting than for approach to a planar molecule, and one would expect to obtain more negative AS* values for phosphoryl compound^.^"' This has been observed in comparing AS* values for the alkaline hydrolysis of carboxylic acid esters3"' to that for the alkaline hydrolysis of phosphonate esters. 39 In addition, large negative AS* values have been reported for other reactions involving ammoniated electron^.^^,^^ It has been suggested that collapse of the cavity of the ammoniated electron can result in large negative AS* values." The increasing (more positive) values of AS* with increasing size of the alkyl substituent has been suggested to be associated with an increased dispersion of charge in the activated complex.…”

Section: Lowing Stoichiometric Reactionmentioning

confidence: 98%

Kinetic study of the reduction of trimethyl phosphate, triethyl phosphate, and tributyl phosphate by sodium in liquid ammonia

Isbell¹,

Dewald²

1987

J. Phys. Chem.

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6695water structure around the 0-group (Scheme 11), which leads to an increase in the activation entropy (A,Seb'(HA-) < a f , b * (A2-)).The inflection observed in Arrhenius plot (Figure 3) would be explainable in two ways. One is due to the conformational change of the reactants in lower temperature range. The other is due to the change of rate-determining step in the reaction in lower temperature range. The "guest-free" water complex of a-CDx as observed in the crystalline stateh will also be present in aqueous sol~tion.'~ In this complex, the-cavity of a-CDx is not "round" owing to the distortion of one of its six glucose units and causes high-energy, "tense" conformation.2b In aqueous solution, however, the dynamic structural interconversion such as a-CDx.2H20-(tense) + a-CDx.2H20(relaxed) would exist.2b This conformational change was confirmed only in a-CDx system by ultrasonic relaxation technique at 25 O C . % If the "tense" conformation is more stable at lower temperature, the binding would be sterically more hindered. Presumably, a conformational change also occurs when the binding with the "tense"-structured a-CDx occurs. Thus, one might expect that the AHf' and A S P ' at lower temperatures are larger than those at higher temperatures (Scheme 111). It is reasonable to guess that the inflection is observed only in the binding process and at about 15 OC irrespective of the kind of the guest molecule, whereas in the dissociation process no inflection is observed.The sharp kinetic anomalies observed in Arrhenius plots for the binding with a-CDx of the guest molecule would be explainable in another way. The second possibility is that the inflection is due to a change in rate-determining step in the binding process with a-CDx. These phenomena have been observed in many enzymatic reactions.21 The third possibility is the change in local order of the hydration structures in the vicinity of the host and the guest molecules. At the present stage of kinetic studies, it is still indefinite whether the sharp anomalies observed in Arrhenius plot are due to the conformational change of a-CDx or to the change of the rate-determining step in the reaction mechanism in the lower temperature range. However, as we shall describe in a future communication, the kinetic studies using the chemically modified a-CDx and some a-naphthylazo derivatives as guest molecule would enable us to advance our knowledge about the temperature dependence of the rate constants, kf and kb, of the inclusion reactions with a-CDx. Registry NO. 1, 98928-28-0; 2, 110773-10-9; 3, 98928-32-6; 4, 98928-34-8; 5, 98928-36-0. (21) Kaplan, H.; Laidler, K. J. Can. J. Chem. 1967, 45, 547. Adams, P. A,; Swart, E. R. Biochem. J. 1977, 161, 83. A sharp kinetic anomaly in Arrhenius plots is observed for the binding and acylation stage of the achymotrypsin-catalyzed hydrolysis of nonspecific p-nitrophenol esters, but not for the deacylation stage.The reactions of trimethyl phosphate, triethyl phosphate, and tributyl phosphate with sodium in liquid ammonia were fo...

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Section: Lowing Stoichiometric Reactionmentioning

confidence: 98%

Kinetic study of the reduction of trimethyl phosphate, triethyl phosphate, and tributyl phosphate by sodium in liquid ammonia

Isbell¹,

Dewald²

1987

J. Phys. Chem.

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“…It was observed that the rate of the hydrolysis was greatly influenced by the nature of the leaving group and the substituents on the phosphorus atom. Aksnes et al studied the alkaline hydrolysis of various diethyl alkyl-, chloromethyl- and dichloromethylphosphonates ( 65 ) in an acetone–water solvent-mixture ( Scheme 39 ) [ 120 ]. The presence of the chloromethyl or dichloromethyl substituents increased the reaction rate.…”

Section: Alkaline and Basic Hydrolysismentioning

confidence: 99%

The Hydrolysis of Phosphinates and Phosphonates: A Review

Harsági

Keglevich

2021

Molecules

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Phosphinic and phosphonic acids are useful intermediates and biologically active compounds which may be prepared from their esters, phosphinates and phosphonates, respectively, by hydrolysis or dealkylation. The hydrolysis may take place both under acidic and basic conditions, but the C-O bond may also be cleaved by trimethylsilyl halides. The hydrolysis of P-esters is a challenging task because, in most cases, the optimized reaction conditions have not yet been explored. Despite the importance of the hydrolysis of P-esters, this field has not yet been fully surveyed. In order to fill this gap, examples of acidic and alkaline hydrolysis, as well as the dealkylation of phosphinates and phosphonates, are summarized in this review.

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“…Some of them require drastic experimental conditions limiting the reaction to molecules with no unstable links. [41][42][43][44] Mild reaction conditions are generally preferred. 45,46 In the present work, even if the methacrylamide function proved to be very stable, deprotection of the phosphonated methyldiester into a diacid form was achieved under mild Fig.…”

Section: Deprotection Of Polymers Bearing Phosphonated Methyldiester ...mentioning

confidence: 99%

Synthesis of fatty phosphonic acid based polymethacrylamide by RAFT polymerization and self-assembly in solution

et al. 2014

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Alkaline Hydrolysis of Diethyl Esters of Alkylphosphonic Acids and Some Chloro-substituted Derivatives.

Cited by 17 publications

References 0 publications

Kinetic study of the reduction of trimethyl phosphate, triethyl phosphate, and tributyl phosphate by sodium in liquid ammonia

Kinetic study of the reduction of trimethyl phosphate, triethyl phosphate, and tributyl phosphate by sodium in liquid ammonia

The Hydrolysis of Phosphinates and Phosphonates: A Review

Synthesis of fatty phosphonic acid based polymethacrylamide by RAFT polymerization and self-assembly in solution

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