INFLUENCE OF SUBSTITUTES ON THE RATE OF THE REACTION OF META- АND PARASUBSTITUTED  BENZOIC  ACIDS  WTH ANILINE, CATALYZED BY POLYBUTOXYTITANATES

The polybutoxytitanates catalysis of acylation of anilines by meta- and parasubstituted benzoic acid results in substituted benzanilides. The rate constants of this second-order reaction (the first in terms of aniline and substituted benzoic acid; boiling ortho-xylene, 145 °С) correlates well according to the Hammett equation with two straight lines for individual groups of substituents with ρ = 1.76 (electron donors) and 0.12 (electron acceptors). Oxybenzoic and phthalic acids, that do not react with aniline and inhibit the interaction of the latter with benzoic acid, fall out of this dependence. Based on these data, as well as the results of a previous studies of the interaction of substituted anilines with a benzoic acid made under comparable conditions, a mechanism of bifunctional catalysis due to the formation of titanium polybutoxybenzoates in the first minutes of the reaction in situ — the true catalysts of the process, is proposed. The nucleophilic center of the catalyst can be represented by the carbonyl group of a substituted benzoate bound to a titanium atom, forming an H-bond with hydrogen atoms of the amino group of aniline, thus activated to react with a substituted benzoic acid. The titanium atoms of polytitanate (coordination catalysis) and their complexes with the resulting substituted benzanilides (acid catalysis) can act as the electrophilic center of a catalyst that activates the carbonyl group of a substituted benzoic acid to nucleophilic attack by aniline. A titanium atom bound to a substituted benzoate exhibits, depending on the nature of the substituent, various catalytic activity.

Download Full-text

INFLUENCE OF SUBSTITUTES ON THE RATE OF THE REACTION OF ORTHOSUBSTITUTED BENZOIC ACIDS WTH ANILINE, CATALYZED BY POLYBUTOXYTITANATES

Ukrainian Chemistry Journal ◽

10.33609/2708-129x.87.03.2021.18-40 ◽

2021 ◽

Vol 87 (3) ◽

pp. 18-40

Author(s):

Leon Shteinberg

Keyword(s):

Benzoic Acid ◽

Rate Constants ◽

Nucleophilic Attack ◽

Benzoic Acids ◽

Substituted Anilines ◽

Hydrogen Atoms ◽

Active Centers ◽

Straight Line ◽

Catalytically Active ◽

Substituted Benzoic Acids

The polybutoxytitanates catalysis of aniline acylation by orthosubstituted benzoic acids leads to the production of substituted benzanilides. Catalytic rate constants of the second order reaction (the first with respect to aniline and ortho-substituted benzoic acid; boiling ortho=xylene, 145°C) correlate well according to the Hammett and Bronsted equations with straight line segments with ρ=1.93 and α=0.66, in contrast to the reaction of aniline with meta- and parasubstituted benzoic acids and substituted anilines with benzoic acid. This dependence drops out 2=nitrobenzoic and 1=naphthoic acids, which have relatively low reactivity and the greatest steric hindrances both for nucleophilic attack by aniline and for possible coordination with catalytically active centers of the corresponding ortho-substituted titanium polybutoxybenzoates formed in situ. Based on these data, the previously proposed mechanism of bifunctional catalysis due to titanium polybutoxybenzoates and their complexes with meta- and parasubstitutedbenzanilides was supplemented by the possibility of the steric inhibition of reaction by the most bulky substituents and chelate structures formation of orthosubstituted benzoic acids and their anilides with individual titanium atoms of the catalyst, as well as the simultaneous H-bonding of the amino group hydrogen atoms of aniline, which leads to its activation to a nucleophilic attack, with a carbonyl group and an orthopositioned substituent of the orthobenzoate ligand in the coordination sphere of titanium. Taking into account such chelation and steric barriers, as well as inhibition of acid catalysis due to the formation of the imide form of anilides, containing electron-withdrawing substituents, the equations for the rate constants of the catalytic reaction of ortho-substituted benzoic acids with aniline are derived, corresponding to the experimentally obtained Hammett dependence.

Download Full-text

INFLUENCE OF SUBSTITUTES ON THE RATE OF REACTION OF SUBSTITUTED ANILINES WITH A BENZOIC ACID, CATALYZED BY POLYBUTOXYTITANATES

Ukrainian Chemistry Journal ◽

10.33609/0041-6045.86.1.2020.36-59 ◽

2020 ◽

Vol 86 (1) ◽

pp. 36-59

Author(s):

Leon Shteynberg

Keyword(s):

Benzoic Acid ◽

Rate Constants ◽

Atmospheric Oxygen ◽

Titanium Atom ◽

Electron Acceptors ◽

Hammett Equation ◽

Substituted Anilines ◽

Strong Electron ◽

Oxidation Processes ◽

Carbonyl Bond

The catalytic production of benzanilide by the interaction of benzoic acid with aniline is an important model process recently intensively developed in the field of the concept of «green chemistry», direct catalytic amidation, and its study is an urgent scientific and practical task. To solve this problem, the effect of substituents in the aniline core on the catalysis by polybut-oxytitanates on acylation of substituted anilines by benzoic acid was studied. The rate constants of this the second-order reaction (the first with respect to substituted aniline and benzoic acid; boiling ortho-xylene, 145 °С, nitrogen flow) are well correlated according to the Hammett equation with three straight lines for individual groups of substituents with ρ = –0.86 (electron donors), 1.12 (weak electron acceptors), –2.83 (strong electron acceptors). To explain this dependence, a variant of the catalytic amidation mechanism is proposed, which takes into account the formation of titanium butoxybenzoates in the first minutes of the reaction — a true amidation catalyst; coordination (polarization of the carbonyl bond in the interaction with the catalyst titanium atom) and acid (polarization of the carbonyl bond in the interaction with the complex of the formed substitu- ted benzanilide with the titanium butoxyben-zoates) catalysis routes. Inhibition of the catalytic reaction is associated with the presence in the mass of water, relative excess of benzoic acid and a possible amide–imide tautomerism of substituted benzanilides, accompanied by the interaction of the imide form of the latter with titanium butoxybenzoates, which does not lead to the route of acid catalysis. The rate constants for catalytic acylation of substituted anilines, containing electron-donating substituents, with benzoic acid in the air are correlated according to the Hammett equation by a straight line segment with ρ = 0.99, which is associated with the predominant influence of the oxidation processes of the corresponding amines. Catalytic acylation under comparable conditions of substituted anilines, containing electron-withdrawing substituents, oxidation processes due to atmospheric oxygen have little effect on.

Download Full-text

EFFECT OF SUBSTITUTED BENZANILIDES ADDITIVES ON THE SPEED OF CATALYZED BY TETRABUTOXYTIITANE AND POLYBUTOXYTIТANATE REACTION OF ANILINE WITH BENZOIC ACID

Ukrainian Chemistry Journal ◽

10.33609/0041-6045.85.1.2019.19-31 ◽

2019 ◽

Vol 85 (1) ◽

pp. 19-31

Author(s):

Leon Yakovlevich Shteinberg

Keyword(s):

Benzoic Acid ◽

Carbonyl Group ◽

Titanium Atom ◽

Partial Hydrolysis ◽

Strong Electron ◽

Reaction Rate Constants ◽

Straight Line ◽

Conjugate Acid ◽

Urgent Task ◽

Electron Withdrawing Substituents

The catalytic synthesis of benzanilide by the interaction of benzoic acid with aniline is an important model reaction of direct catalytic amidation that has been intensively developed recently in the field of the concept of «green chemistry», and its study is an urgent task. In the framework of solving this problem the effect of the final product - benzanilide, and its substituted on catalysis by tetrabutoxytitanium and its partial hydrolysis products (polybutoxytitanates) was studied. With an increase in the concentration of the preliminary addition of benzanilide, the initial rate of catalytic interaction of benzoic acid with aniline decreases monotonically. Benzanilide itself does not catalyze the amidation process, does not hydrolyze under reaction conditions by water, and does not undergo other changes in the reaction mass. The kinetics of the formation of benzanylide in the presence of additives of a number of substituted benzanilides, containing electron-withdrawing substituents, showed higher values of the reaction rate constants as compared to that for the formation of benzanilide in the absence of any additives. This suggests the presence of two routes of catalysis: the coordination route (polarization of the carbonyl group of the benzoic acid due to the interaction with the atom of titanium) and acid route. The latter can be associated with the formation of complexes due to the coordination of the titanium atom of the catalyst with the carbonyl group of the substituted benzanilide, the appearance of a relatively acidic NH=group and catalysis of conjugate acid: the titanium-containing catalyst + the corresponding substituted benzanilide. The formation of such a catalytic complex, by the example of a pair of benzanilide + tetrabutoxytitanium, was confirmed by the NMR 1H spectroscopy method. Catalysis of aniline acylation with benzoic acid in the presence of additions meta= and para=substituted benzanilides correlates well with the Hammett equation with two straight line segments with ρ=0.478 and ρ=-0.235, with a maximum, indicating a different effect of substituted benzanilides containing electron-donating and strong electron-withdrawing substitutes on the complexation with tetrabutoxytitanium and polybutoxytitanium and the change in their catalytic activity. The decrease in the rate of the catalytic formation of benzanilide is especially pronounced with the addition of ortho=substituted benzanilides, containing strong electron-withdrawing substituents, which at the same time have a high steric effect.

Download Full-text

Synthesis of a sucrose dimer with enone tether; a study on its functionalization

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.10.124 ◽

2014 ◽

Vol 10 ◽

pp. 1246-1254 ◽

Cited By ~ 7

Author(s):

Zbigniew Pakulski ◽

Norbert Gajda ◽

Magdalena Jawiczuk ◽

Jadwiga Frelek ◽

Piotr Cmoch ◽

...

Keyword(s):

Circular Dichroism ◽

Double Bond ◽

Carbonyl Group ◽

Osmium Tetroxide ◽

Cd Spectroscopy ◽

Allylic Alcohol ◽

Circular Dichroïsm

The reaction of appropriately functionalized sucrose phosphonate with sucrose aldehyde afforded a dimer composed of two sucrose units connected via their C6-positions (‘the glucose ends’). The carbonyl group in this product (enone) was stereoselectively reduced with zinc borohydride and the double bond (after protection of the allylic alcohol formed after reduction) was oxidized with osmium tetroxide to a diol. Absolute configurations of the allylic alcohol as well as the diol were determined by circular dichroism (CD) spectroscopy using the in situ dimolybdenum methodology.

Download Full-text

Computational and experimental investigations of one-step conversion of poly(carbonate)s into value-added poly(aryl ether sulfone)s

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1600924113 ◽

2016 ◽

Vol 113 (28) ◽

pp. 7722-7726 ◽

Cited By ~ 29

Author(s):

Gavin O. Jones ◽

Alexander Yuen ◽

Rudy J. Wojtecki ◽

James L. Hedrick ◽

Jeannette M. García

Keyword(s):

High Performance ◽

Density Functional ◽

Value Added ◽

Single Step ◽

Nucleophilic Attack ◽

Experimental Investigations ◽

Aryl Ether ◽

One Step ◽

Poly Carbonate

It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers.

Download Full-text

In-situ low temperature cleaning of silicon surfaces using hydrogen atoms

Vacuum ◽

10.1016/0042-207x(94)00151-0 ◽

1995 ◽

Vol 46 (7) ◽

pp. 667-672 ◽

Cited By ~ 10

Author(s):

A Crossley ◽

C.J. Sofield ◽

S Sugden ◽

R Clampitt ◽

C Bradley

Keyword(s):

Low Temperature ◽

Silicon Surfaces ◽

Hydrogen Atoms

Download Full-text

Synthesis of 1-acyl- and 1-(thioacyl)-4-benzylpiperazines as potential antidepressants

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19901817 ◽

1990 ◽

Vol 55 (7) ◽

pp. 1817-1827 ◽

Cited By ~ 3

Author(s):

Vojtěch Kmoníček ◽

Emil Svátek ◽

Jiří Holubek ◽

Miroslav Ryska ◽

Martin Valchář ◽

...

Keyword(s):

Benzoic Acid ◽

Thionyl Chloride ◽

Antidepressant Activity ◽

Acid Chlorides ◽

Phosphorus Pentasulfide ◽

Antidepressant Agent ◽

Dimethylaminobenzoic Acid ◽

Amino Amides

2-Nitro, 3-nitro- and 4-nitrobenzoyl chloride were reacted with 1-benzylpiperazine in benzene in the presence of triethylamine and gave the amides IV-VI, the first of which is considered a bioisostere of the antidepressant agent piberaline (I). 2-Dimethylamino-, 3-dimethylamino- and 4-dimethylaminobenzoic acid were treated with thionyl chloride in benzene in the presence of triethylamine or pyridine, and the acid chlorides formed were reacted in situ with 1-benzylpiperazine affording the amides VII-IX. The amides I and IV-VI were transformed by treatment with phosphorus pentasulfide in pyridine to the thioamides X-XIII. 4-(Dimethylaminomethyl)benzoic acid was reacted with 1-benzylpiperazine in dimethylformamide in the presence of N,N'-carbonyldiimidazole and afforded the amide XIV. Heating of ethyl 5-methylimidazole-4-carboxylate with 1-benzylpiperazine to 200-210 °C gave the amide XV together with the unexpected 1-benzyl-4-ethylpiperazine (XVI). The oily or crystalline bases of the amino amides or thioamides were mostly transformed to crystalline salts and characterized by spectra. Out of the compounds prepared only X (V⁄FB-17 070) and XIV (V⁄FB-17 114) showed indications of efficacy in tests which are considered indicative of antidepressant activity. Compounds VII, VIII, and X appeared to be mildly antidopaminergic - similarly like piberaline (I), and compounds IV, V, XI, XIV, and XV on the contrary showed signs of dopaminominetic activity.

Download Full-text

The lanthanide-shifted N.M.R. spectra of some cyclopentadienone-cobalt complexes

Australian Journal of Chemistry ◽

10.1071/ch9751681 ◽

1975 ◽

Vol 28 (8) ◽

pp. 1681 ◽

Cited By ~ 7

Author(s):

RS Dickson ◽

SH Johnson ◽

ID Rae

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Carbonyl Group ◽

Structure Determination ◽

Cobalt Complexes ◽

Hydrogen Atoms ◽

Pseudocontact Shifts ◽

Lone Pairs ◽

Nuclear Magnetic Resonance Spectra ◽

Lanthanide Shift Reagents

The effect of the lanthanide shift reagents, Eu(fod)3 and Pr(fod)3, on the nuclear magnetic resonance spectra of some (η4-cyclopentadienone)(η- cyclopentadienyl)cobalt complexes has been investigated as an aid to structure determination in this series. The lanthanides complex with the lone pairs of the carbonyl group. Pseudocontact shifts are observed for hydrogens attached to each ring and for hydrogen atoms in substituents on the cyclopentadienone. With Eu(fod)3, contact shifts are also observed for the cyclopentadienone ring hydrogens.

Download Full-text

Facile Synthesis of Pd@PtM (M = Rh, Ni, Pd, Cu) Multimetallic Nanorings as Efficient Catalysts for Ethanol Oxidation Reaction

Frontiers in Chemistry ◽

10.3389/fchem.2021.683450 ◽

2021 ◽

Vol 9 ◽

Author(s):

Xingqiao Wu ◽

Xiao Li ◽

Yucong Yan ◽

Sai Luo ◽

Jingbo Huang ◽

...

Keyword(s):

Benzoic Acid ◽

Epitaxial Growth ◽

Oxidation Reaction ◽

Ethanol Oxidation ◽

Hollow Structure ◽

Ethanol Oxidation Reaction ◽

Hollow Nanostructures ◽

Oxidative Etching ◽

General Method

Pt-based multimetallic nanorings with a hollow structure are attractive as advanced catalysts due to their fantastic structure feature. However, the general method for the synthesis of such unique nanostructures is still lack. Here we report the synthesis of Pd@PtM (M = Rh, Ni, Pd, Cu) multimetallic nanorings by selective epitaxial growth of Pt alloyed shells on the periphery of Pd nanoplates in combination with oxidative etching of partial Pd in the interior. In situ generation of CO and benzoic acid arising from interfacial catalytic reactions between Pd nanoplates and benzaldehyde are critical to achieve high-quality Pt-based multimetallic nanorings. Specifically, the in-situ generated CO promotes the formation of Pt alloyed shells and their epitaxial growth on Pd nanoplates. In addition, the as-formed benzoic acid and residual oxygen are responsible for selective oxidative etching of partial Pd in the interior. When evaluated as electrocatalysts, the Pd@PtRh nanorings exhibit remarkably enhanced activity and stability for ethanol oxidation reaction (EOR) compared to the Pd@PtRh nanoplates and commercial Pt/C due to their hollow nanostructures.

Download Full-text