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Simanenko, Yu. S.; Popov, A. F.; Prokop’eva, T. M.; Karpichev, Yevgen; Belousova, І. A.; Savëlova, V. A.

doi:10.1023/a:1020515831658

Cited by 18 publications

(44 citation statements)

References 6 publications

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“…This conclusion is also valid for the other acyl-containing substrates, in particular, for 4-nitrophenyl acetate (IV) [13,14], 4-nitrophenyl diphenylphosphate [10] etc. [3,8]. Secondly, Bro \ nsted relationships for oximate and amidoximate ions virtually coincide (Fig.…”

Section: ) O-nucleophilic Features Of Amidoximesmentioning

confidence: 66%

“…Therefore the Scheme 6. Tables 2 and 3, for oximate ions are taken from [8,15,31]. Bro \ nsted parameters for all relations are given in Table 4.…”

Section: ) O-nucleophilic Features Of Amidoximesmentioning

confidence: 99%

“…Amidoximes are oxime derivatives, but both their neutral and anionic form operate as acyl group acceptor [1014]. The kinetic behavior of amidoximes resembles in this respect rather that of hydroxylamine which also is capable to react with an acylating agent in neutral and anionic form [15,16] and is a unique a-nucleophile ensuring high reaction rates in basic, neutral, and acidic media. The hydroxylamine anion is a leader with respect to the O-nucleophilic reactivity in the series of known classes of the a-nucleophiles [15].…”

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confidence: 99%

“…The kinetic behavior of amidoximes resembles in this respect rather that of hydroxylamine which also is capable to react with an acylating agent in neutral and anionic form [15,16] and is a unique a-nucleophile ensuring high reaction rates in basic, neutral, and acidic media. The hydroxylamine anion is a leader with respect to the O-nucleophilic reactivity in the series of known classes of the a-nucleophiles [15]. Aiming at development of systems for cleavage of ecotoxic substrates [9,17] we measured in this study the reaction rates between the neutral and anionic forms of amidoximes and 4-nitrophenyl esters of 4-toluenesulfonic (I), diethylphosphoric (II), and diethylphosphonic (III) acids,* estimated the a-effect value, revealed the factors controlling the O-nucleophilic features of the amidoximes, and the place these a-nucleophiles occupy among the known supernucleophiles.…”

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O-nucleophilic features of amidoximes in acyl group transfer reactions

et al. 2004

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Analysis of kinetic behavior of isomeric Z-amidoximes and their Z-ions in reactions with 4-nitrophenyl-4-toluenesulfonate, diethylphosphate, and diethylphosphonate was performed in the framework of Bro \ nsted relationship. The reactivity of amidoximate anions with respect to the mentioned substrates is comparable to that of typical a-nucleophiles, oximate ions. The a-effect decreased with the growing basicity of amidoximate ions, and for compounds with pK a >12.0 it was totally lacking. The high nucleophilic activity of neutral amidoximes and their anionic forms was ascribed to the cyclic structure of the transition state involving two kinds of assistance: general acidic, and basic catalysis. A unique feature of amidoximes as a-nucleophiles consists in their ability to perform efficient cleavage of ecotoxic substrates in a wide pH range, from basic to acid media.Hydroxylamine oximes, amidoximes, and hydroxamic acids [19] occupy a special place in the series of typical a-nucleophiles for just among them efficient reactivators of cholinesterase has been found that are still required and whose preparation is attempted up till now [2,3,9]. The main attention nowadays in this field of research is attracted by the nature of the factors providing the abnormally high reactivity of a-nucleophiles [28]. Nonetheless, the O-nucleophilic characteristics of amidoximes in acyl transfer reactions were not subjected to detailed kinetic investigation. Amidoximes are oxime derivatives, but both their neutral and anionic form operate as acyl group acceptor [1014]. The kinetic behavior of amidoximes resembles in this respect rather that of hydroxylamine which also is capable to react with an acylating agent in neutral and anionic form [15,16] and is a unique a-nucleophile ensuring high reaction rates in basic, neutral, and acidic media. The hydroxylamine anion is a leader with respect to the O-nucleophilic reactivity in the series of known classes of the a-nucleophiles [15]. Aiming at development of systems for cleavage of ecotoxic substrates [9, 17] we measured in this study the reaction rates between the neutral and anionic forms of amidoximes and 4-nitrophenyl esters of 4-toluenesulfonic (I), diethylphosphoric (II), and diethylphosphonic (III) acids,* estimated the a-effect value, revealed the factors controlling the O-nucleophilic features of the amidoximes, and the place these a-nucleophiles occupy among the known supernucleophiles. 2 0H 6 2 12 2 , (W2 2 (W 2 3 3 (W2 2 12 (W2 2 ,, ,,,Isomerism and acid-base properties of amidoximes. The reactivity of typical a-nucleophiles, oximate ions, depends on the definite configuration (Z-or E-) that they take in the reaction with the acylating agents. As an example a Bro \ nsted relationship may be cited for reactions of substituted benzaldoximate ions with 4-nitrophenyl acetate (IV) and thioacetate: the E-isomers of * Esters II and III known under the names paraoxone and armin are typical cholinesterase inhibitors, belong to the class of stable ecotoxic substrates, and are only a little...

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Section: ) O-nucleophilic Features Of Amidoximesmentioning

confidence: 66%

“…Therefore the Scheme 6. Tables 2 and 3, for oximate ions are taken from [8,15,31]. Bro \ nsted parameters for all relations are given in Table 4.…”

Section: ) O-nucleophilic Features Of Amidoximesmentioning

confidence: 99%

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O-nucleophilic features of amidoximes in acyl group transfer reactions

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“…The classical method for the synthesis of imidazole [78][79][80] and pyrazole [81,82] derivatives of aldoximes and ketoximes is based on the reaction of the aldehyde or ketone with hydroxylamine hydrochloride in the NaOAc/MeOH [83], NaOAc/H 2 O/MeOH [84], MeOH [85], EtOH/pyridine [86], or NaHCO 3 /EtOH [87] systems. In a few papers the synthesis of aldoximes and ketoximes imidazolium salts was described [87,88]. It was established that the reaction of the nitrone 92 with hydroxylamine leads to the oxime 93 with a yield of 30% [89].…”

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Oximes of five-membered heterocyclic compounds with two heteroatoms. 1. Synthesis and structure (Review)

Абеле

Lukevics

2007

Chem Heterocycl Compd

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Data on the production and structure of oxazole, thiazole, and imidazole aldoximes, ketoximes, and amidoximes and their derivatives are reviewed.The oximes of five-membered heterocyclic compounds with two heteroatoms are widely used as intermediates in fine organic synthesis. The principal methods for the production of oxazole, thiazole, and imidazole aldoximes, ketoximes, amidoximes, and their derivatives are summarized in this review. The principal methods of investigation of the structure of the oximes of five-membered heterocyclic compounds with two heteroatoms in relation to their isomerism are examined briefly. The characteristics of the reactions and biological activity of the oximes of five-membered heterocyclic compounds with two heteroatoms will be presented in the second part of the review.

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Micellar effects of surfactants in cleavage of 4-nitro-phenyl diethyl phosphonate by hydroperoxide anion

et al. 2006

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We have studied the nucleophilicity of the hydroperoxide anion relative to 4-nitrophenyl diethyl phosphonate (NPDEPS) in the presence of cetyltrimethylammonium bromide (water, 25°C) while varying the acidity of the medium and the hydroperoxide anion concentration over a broad range. The increase in the reaction rate when the reaction is transferred to a micellar pseudophase is as high as~10-fold, which is explained by concentration effects. In CTAB micelles, as in water, the hydroperoxide ion is one of the most effective a-nucleophiles, and the size of the a-effect, characterized by the ratio of the second-order rate constants for reactions of HOO -and OH -anions with NPDEPS, remains practically constant and reaches a value of 50-fold. Key words: nucleophilic substitution, 4-nitrophenyl diethyl phosphonate, hydroperoxide anion, cetyltrimethylammonium bromide, micellar effects.Rapid and irreversible cleavage of different types of ecotoxin substrates requires design of "green" soft systems with a broad spectrum of action [1,2]. Of special interest from this standpoint are microheterogeneous systems based on hydrogen peroxide and surfactants [2][3][4]. The advantages of such systems are obvious: the surfactant ensures effective solubilization of the substrate, the hydroperoxide anion is a typical a-nucleophile, HOOH is an oxidizing agent, i.e., the HOO -/HOOH pair represents a universal system [2, 5]. However, hydrogen peroxide is a relatively weak oxidizing agent. In order to enhance the oxidizing properties of HOOH, we can use acidic activators, leading to formation of peroxy acids [2-6]. The prospects for such an approach are clearly demonstrated by creation of the Decon Green formula [2], effectively destroying not only organophosphorus compounds (OPCs) but also sulfide derivatives (for example, mustard agent).The aim of this work was to study the nucleophilic reactivity of the hydroperoxide anion in cleavage of 4-nitrophenyl diethyl phosphonate (NPDEPS) in the presence of a cationic detergent: cetyltrimethylammonium bromide (CTAB). This reaction series will be considered as standard in studying the effect of hydrogen peroxide activators on the nucleophilicity and oxidizing ability of the HOO -/HOOH system in degradation of organophosphorus compounds and sulfide derivatives in microheterogeneous media.The CTAB micelles catalyze cleavage of NPDEPS by the hydroperoxide anion, and the dependence of the observed pseudo-first order rate constants k obs , s -1 on C 0 (the analytical concentration of CTAB) is typical for a second order reaction in the presence of a surfactant (Fig. 1a). The kinetic curves k obs vs. C 0 pass through a maximum at C 0 = C opt , the position of which 364 0040-5760/06/4206-0364

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Cited by 18 publications

References 6 publications

O-nucleophilic features of amidoximes in acyl group transfer reactions

O-nucleophilic features of amidoximes in acyl group transfer reactions

Oximes of five-membered heterocyclic compounds with two heteroatoms. 1. Synthesis and structure (Review)

Micellar effects of surfactants in cleavage of 4-nitro-phenyl diethyl phosphonate by hydroperoxide anion

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