Kinetics and mechanism of triphenylphosphine quarternization with unsaturated carboxylic acids in the medium of acetic acid

Kinetics of reaction of triphenylphosphine with a series of unsaturated carboxylic acids and related esters in the medium of acetic acid as well as in mixtures of acetic acid and acetonitrile was studied by spectrophotometry. The data obtained show that the process of quarternization should be described by kinetic equation of third order, the proton transfer occurs from the solvent. A stepwise mechanism of interaction including formation of prereaction complex on the reaction pathway is proposed. © 2009 Pleiades Publishing, Ltd

Synthesis of carboxylate arsenobetaines based on (carboxyalkyl)triphenylarsonium halides

© 2015 Pleiades Publishing, Ltd. It has been found that the reaction of triphenylarsine with unsaturated carboxylic acids (acrylic, maleic, and itaconic ones) supposed to yield the arsenobetaines does not occur, in contrast to similar reactions of carboxylic acids with tertiary phosphines. However, the interaction of tertiary arsines with the halogenated carboxylic acids has resulted in the corresponding tertiary arsonium salts, dehydrohalogenation of the latter affording the target carboxylate betaines in the quantitative yield; the products structure has been elucidated using a set of chemical, physical, and physico-chemical methods. Antibacterial activity of the prepared compounds has been studied

5-Amino-Substituted Derivatives of 4-Nitrofurazane: Synthesis, Structure, and Biological Activity

© 2018, Pleiades Publishing, Ltd. New amination reactions of 5-chloro-4-nitrobenzofurazane with different amines were studied. The reactions of 5-chloro-4-nitrobenzofurazane with 2,4,6-trichloro-, para-acetyl-, and para-carboxyethylanilines gave the products of aromatic nucleophilic substitution of the chlorine substituent in the nitrogenous heterocycle, the composition and structure of which was established by chemical, physical, and physicochemical methods and X-ray diffraction analysis. The thermal stability was studied by synchronous thermogravimetry and differential scanning calorimetry (TG‒DSC). The synthesized compounds showed a high antibacterial and antimycotic activity against human and animal pathogenic microflora

Kinetic study of the reaction of triphenylphosphine with acrylic acid in alcohol media

Kinetic study of the reaction of triphenylphosphine with acrylic acid in alcohol media was carried out by spectrophotometric method. Use of alcohols as solvents is shown to introduce a specific feature in the kinetic picture of the reaction due to the appearance of parallel channels of proton transfer: from alcohol and from another molecule of acrylic acid in the solution. © 2010 Pleiades Publishing, Ltd

C→N migration of methoxycarbonyl and acetyl groups in reactions of functionally substituted carbanions with aryl isocyanates. Kinetics and mechanism of the reactions

The kinetics and mechanism of C→N migrations of methoxycarbonyl and acetyl groups in the reactions of the sodium derivative of methyl (2-cyano-2-phenyl)acetate and 1,1-diacetyl-2-phenyl-2-tributylphosphonioethanide with aryl isocyanates were studied by spectrophotometry. The reactions afford a prereaction complex via a concerted mechanism, according to which the nucleophilic attack of the carbanionic center to the carbon atom of the isocyanate group and the subsequent nucleophilic attack of the nitrogen atom to the carbonyl carbon atom, resulting in the C-C bond cleavage, occur almost simultaneously in the framework of the same transition state. © Springer Science+Business Media, Inc. 2006

Kinetics and mechanism of quaternization of tertiary phosphines with unsaturated carboxylic acids. Kinetic studies of the reactions in aprotic solvents

Data obtained while studying the kinetics of quaternization of tertiary phosphines with the unsaturated carboxylic acids in the series of aprotic solvents indicate the participation of a second molecule of acid playing the part of the external proton donor in this process. Quantitative analysis of the effect of solvent within the frames of the Koppel-Palm equation showed that the main contribution in the reaction rate belongs to the nucleophilicity of medium while the effects of polarity and electrophilicity are smaller. The results obtained suggest the step-by-step mechanism of interaction including the formation of the zwitterionic intermediate on the reaction pathway common for the solvents with different proton activity. © Pleiades Publishing, Ltd., 2011

The synthesis and reactions of betaines formed in reactions of tertiary phosphines with unsaturated carboxylic acids and their derivatives

On the basis of our systematic investigations, the main trends concerning synthesis, structure, and reactivity of carboxylate phosphabetaines - phosphorus analogs of organic aminoacids - are considered and analyzed. A wide series of phosphabetaines has been obtained in reactions of tertiary phosphines with unsaturated mono- and dicarboxylic acids, and also with their derivatives - esters and amides. By a plethora of experimental and theoretical methods, it has been shown that the thermodynamic stability of carboxylate phosphabetaines essentially depends on the structure of the initial phosphine and carboxylic acid. In some cases, the reaction between them is equilibrated. On the other hand, for a number of synthesized betaines, it is reliably established that these exist in equilibrium with isomeric phosphoranes. The extremely important condition for stabilization of phosphabetaine structures is the presence of proton-donating reagents, which are included in their crystal lattice. In the series of symmetrically substituted derivatives, the interesting phenomenon of phosphorotropy of the phosphonium group is established. The reactivity of phosphabetaines in reactions with electrophilic reagents (haloid alkyls and acyls, isocyanates, corbodiimides) has been investigated. The majority of key structures have been confirmed by the direct X-ray method. © 2006 Wiley Periodicals, Inc

Synthesis and antimicrobial activities of phosphonium salts on basis of triphenylphosphine and 3,5-di-tert-butyl-4-hydroxybenzyl bromide

We report the structures of two new phosphonium salts prepared via the reaction of (substituted)benzyl bromides with triphenylphosphine. The antibacterial and antifungal activities are reported. © 2013 Copyright Taylor and Francis Group, LLC

New di- and tricarboxylate phosphabetaines

© 2016, Springer Science+Business Media New York.New stable tricarboxylate phosphabetaines were synthesized based on 3-(diphenylphosphino)propionic acid and unsaturated dicarboxylic acids (maleic and itaconic). A new dicarboxylate phosphabetaine was synthesized based on 1,3-bis(diphenylphosphino)propane, which did not contain any proton-donor reagents in its crystal lattice

Synthesis of carboxylate phosphabetaines from 3-(diphenylphosphino)propanoic acid and unsaturated monocarboxylic acids

© 2015 Pleiades Publishing, Ltd. Stable dicarboxylate phosphabetaines were synthesized by the phosphorylation of a series of unsaturated monocarboxylic acids (acrylic, crotonic, methacrylic, and cinnamic) with 3-(diphenylphosphino)-propanoic acid. The structure of the products was assessed by chemical, physical, and physicochemical methods. Alkylation of 3-(diphenylphosphino)propanoic acid with methyl iodide was studied for the first time to show that the reaction proceeds smoothly and yields the corresponding quaternary phosphonium salt