Unsaturated Acid Derivatives Research Articles

Cu(II)-Catalysed Hydrocarboxylation of Imines Utilizing CO2 to Synthesize α-Unsaturated Aminocarboxylic Acids

Here, we report the Cu(II)-photocatalysed hydrocarboxylation of imines (C=N) from a series of synthesized Schiff Base derivatives, namely (E)-1-(4-((4-methylbenzylidene)amino)phenyl)ethanone, (E)-1-(3-((5-bromo-2-hydroxybenzylidene)amino)phenyl)ethanone, (E)-4-((5-bromo-2-hydroxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one, and (E)-1,5-dimethyl-4-((4-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-one, with carbon dioxide (CO2) to generate disubstituted amino acids. Under mild conditions (atmospheric pressure of CO2, room temperature, and 30 W Blue LED light), good to excellent yields confirming the formation of substituted amino acid unsaturated acid derivatives were obtained. Single crystal X-ray diffraction (SC-XRD) and UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS) confirmed the square pyramidal geometry of the Cu(II) photocatalyst. Docking and DFT calculations of the substituted amino acid unsaturated acid derivatives showed their potential as antimicrobial molecules.

ChemInform Abstract: Asymmetric (2 + 2)Cycloaddition Reaction Between α,β- Unsaturated Acid Derivatives and Alkynyl or Alkenyl Sulfides Catalyzed by a Chiral Titanium Reagent.

Asymmetric [2+2] cycloaddition reaction between 3-(acryloyl)-1,3-oxazolidin-2-one derivatives and alkynyl or alkenyl sulfides proceeds by the use of a chiral titanium reagent to give the corresponding cyclobutene or cyclobutane derivatives in high enantioselectivity.

New unsaturated derivatives of Xanthan gum: Synthesis and characterization

Unsaturated Xanthan derivatives, which can be used for the development of biodegradable three-dimensional networks having hydrogel properties, were prepared by esterification under various conditions. Xanthan gum derivatives with different degrees of substitution were obtained by reaction with an unsaturated organic acid (acrylic acid) or with acid reactive derivatives (acryloyl chloride, maleic anhydride). The presence of acrylate and maleate groups in the modified structure of Xanthan gum was detected by ATR–FTIR, 1H liquid NMR and 1H HRMAS NMR spectroscopies. The degree of substitution as determined by 1H NMR could be controlled by varying the chemical nature of functionalisation agent, reaction time and temperature.The results proved that this polysaccharide can be modified by esterification with acids or unsaturated acid derivatives for further synthesis of hydrogels. Maleic anhydride presents a higher reactivity as compared to acrylic acid and acryloyl chloride.

Synthesis of new functional derivatives of pyrazolidine from 1-acetyl-3-methyl-5-nitromethyl-2-phenylpyrazolidine

3-Nitromethylpyrazolidine reacts with derivatives of unsaturated acids and reducing agents with the formation of polyfunctional compounds of the pyrazolidine nucleus.

Expanding the Scope of Atropisomeric Monodentate P‐Donor Ligands in Asymmetric Catalysis: Hydrogen‐Transfer Reduction of α,β‐Unsaturated Acid Derivatives by Rhodium/Ph‐binepine Catalysts

AbstractA range of α,β‐unsaturated acids and esters have been selectively reduced to the corresponding saturated acid derivatives by hydrogen transfer. As the reducing agent, formic acid was used in the presence of RhI complexes formed with the powerful chiral ligand Ph‐binepine (1), an axially chiral binaphthalene‐type monodentate P‐donor ligand. Very high stereoselectivities (up to 97% ee) were obtained in the case of itaconic acid (2a).

Alkoxycarbonylation of 3,3,3-Trifluoropropyne: an Intriguing Reaction to Prepare Trifluoromethyl-Substituted Unsaturated Acid Derivatives

The addition of CO and methanol to 3,3,3-trifluoropropyne is catalysed by Pd(OAc)2 in the presence of (6-methylpyrid-2-yl)diphenylphosphine and CH3SO3H. The main products of the reaction are the methyl esters of 2-(trifluoromethyl)propenoic acid 1 and of 3-(trifluoromethyl)propenoic acid 2 (4,4,4-trifluorobut-2-enoic acid). The regioselectivity of the reaction can be controlled to a great extent by a suitable choice of the composition of the catalytic system and the reaction conditions. Thus, 1 can be obtained in 93% yield by using P(CO)=20 atm and high ligand/Pd and acid/Pd ratios. On the other hand, selectivity up to 85% in 2 can be achieved using P(CO)=80 atm and a low ligand/Pd ratio together with a high acid/Pd ratio. The reaction mechanism is also discussed.

9-Hydroxy-10,12-octadecadienoic acid (9-HODE) and 13-hydroxy-9,11-octadecadienoic acid (13-HODE): excellent markers for lipid peroxidation

Various conditions for conversion of (9 S,10 E,12 Z)-9-hydroperoxy-10,12-octadecadienoic acid (9 S-HPODE) and (13 S,9 Z,10 E)-13-hydroperoxy-9,11-octadecadienoic acid (13 S-HPODE) into the corresponding hydroxy acids, (9 S,10 E,12 Z)-9-hydroxy-10,12-octadecadienoic acid (9 S-HODE) and (13 S,9 Z,10 E)-13-hydroxy-9,11-octadecadienoic acid (13 S-HODE), were investigated in vitro. 9 S-HODE and 13 S-HODE were subjected to lipid peroxidation under various conditions: oxidation was carried out in air only, and in air/Fe 2+/ascorbate, air/H 2O 2/Fe 2+, air/Fe 2+, and air/Fe 3+. In contrast to the corresponding hydroperoxides (9 S-HPODE and 13 S-HPODE), 9-HODE and 13-HODE proved to be stable in all these oxidation experiments. Unexpectedly, hydroxy compounds obtained by reduction of hydroperoxides derived from arachidonic acid were not attacked by air/Fe 2+/ascorbate or air/Fe 2+. Thus, for instance, (15 S,5 Z,8 Z,11 Z,13 E)-15-hydroxy-5,8,11,13-eicosatetraenoic acid (15-HETE) remained unchanged in spite of possessing the structural prerequisites for attack by radicals, i.e. a CH 2-group located between two double bonds. Consequently, metal-induced air oxidation reactions of these systems seem to be restricted to hydroperoxides of unsaturated acids (LOOH) and not to corresponding hydroxy compounds (LOH). The reported experiments explain why hydroxy derivatives of unsaturated acids, especially 9-HODE and 13-HODE, are enriched in naturally occurring lipid peroxidation (LPO) processes to a greater extent than any other LPO product and why they are nearly ideal markers for LPO.

ChemInform Abstract: Unsaturated Acid Derivatives in Diels‐Alder Cycloadditions: Effect of the Extended or Cross Conjugation.

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Unsaturated acid derivatives in diels-alder cycloadditions: effect of the extended or cross conjugation.

Behaviour of pentadienoic acid derivatives in Diels-Alder cycloadditions has been examined in the light of experimental results and theoretical calculations. The effect of cross conjugation to an electron-releasing group has also been investigated for these systems and for simple acrylic acid derivatives.

Addition of sulfenyl chlorides to derivatives of ?,?-unsaturated acids and hydrolysis of obtained adducts

1. The kinetically controlled addition of alkane (and benzene) sulfenyl chlorides to β-benzalpropionic acid derivatives gave derivatives of β-alkthio-γ-chloro-γ-phenylbutyric acids, which in a moisture-free medium are isomerized to the more stable β-chloro derivatives. 2. The hydrolysis of the C-Cl bond of derivatives of both γ-chloro- and γ-chloro-β(γ)-alkthio-γ-phenylbutyric acids gives β-alkthio-γ-butyrolactones. The hydrolysis proceeds with anchimeric involvement of the sulfur via episulfonium ions. 3. Contrary to the accepted concepts, it is postulated that the addition of sulfenyl chlorides to the derivatives of unsaturated acids and the hydrolysis of the C-Cl bond of the obtained adducts proceed via different intermediates.

Amphoteric surfactants from mixed N‐alkylethylenediamine

AbstractThe preparation of amphoteric surfactants by the condensation of mixed N‐alkylethylenediamines and unsaturated acid derivatives, particularly acrylic acid esters, was studied. The reaction proceeded readily near 100 C either neat or with solvents. Saponification of the ester products yielded salts which were water‐soluble. The mono‐ and disodium salts of mixed N‐alkyl (C11.5 av) ethylenediamine dipropionic and diisobutyric acid (crotonic acid derived) as 1% active in water were completely soluble at all pH levels. The solutions demonstrated no perceptible isoelectric range on addition of 1–10% concentrations of sodium chloride. Data on surface tension, solubility, calcium tolerance, foam, viscosity, color, and density are presented.

Study of destruction process of organotin derivatives of copolymers on basis vinyl‐chloride and unsaturated acids

AbstractRadical copolymerization has been investigated between vinylchloride and organotin (lead) derivatives of unsaturated acids (bis‐triethyl‐stannylmaleate, β‐phenyl‐tri‐n‐butylstannylacrylate, and tri‐n‐butylstannylmethacrylate and their organic analogs (maleic anhydride andn‐butylmethacrylate). The esterification has been studied of copolymers of vinyl‐chloride and unsaturated acids by organic, organotin (lead) hydroxyl containing compounds and the latter dehydration productsbis‐trialkyltin oxides. The probabilities of forming various compositions (F(M)n, fM1‐M1, fM2‐M2fM1‐M2, or fM2‐M1) in copolymers have been calculated as well as probability of distributing monomer units along the macromolecular chain. Symbat relationship has been established between the probability of forming fM1‐M2and fM2‐M1compositions and thermo‐ and light‐stability of copolymers. The compositions of organotin comonomers and their copolymers with vinylchloride have been investigated. The stabilizing effect of organotin (lead) comonomers in their copolymers with vinylchloride has been revealed, consisting in coordinate interaction of metal atoms with chlorine substituents. The method has been worked out for examing light‐ and thermo‐stability of organotin (lead) copolymers. The stabilizing action of the side organotin (lead) groups on the starting temperature of copolymers, as well as on the induction period duration and the total rate of HCl isolation, has been determined. The occurrence of intermolecular coordinate bonds in the synthesized copolymer macromolecules has been revealed, this fact being the cause of a marked decrease in the copolymers dehydrochlorination rate.

On the polymerization of polyfunctional compounds

AbstractThe present investigation is a two‐sided approach to polyfunctional compounds, namely: (1) polymerization of unsaturated monomers containing reactive groups, in particular, methylol derivatives of unsaturated acids; (2) cyclopolymerization of diolefinic monomers. In the first method of attack conditions have been investigated under which soluble, linear polymers are formed. Our studies have thrown light on the mechanism of reactions facilitating the formation of crosslinks. From a study of the polymerization of methylolacrylamide monomers (in collaboration with L. M. Novichkova) it became possible to direct the reaction towards the formation of soluble, linear polymers. The possibility of further conversions such as transformation of the linear polymers to three‐dimensional ones leads to the polymerization‐condensation concept of polymer formation. This is of particular interest, since it provides the basis for predetermined modification of polymer properties (for example, elimination of flow, increase of strength, chemical resistance, etc.). The reactivity of the methylolamide group allows the use of the compounds in question for these purposes, for instance as copolymer with acrylonitrile. The second method of attack is the cyclic polymerization of symmetrical and unsymmetrical diolefine monomers and of compounds arising in the process of polymerization of 1–6 unsaturated systems. Earlier, Butler, Marvel, Jones and others pointed out the formation of linear cyclic polymers in the polymerization of symmetric divinyl and diallyl monomers unsaturated in the 1,5‐ and 1,6‐positions. The authors of the present work have synthesized a number of acetals of vinyl alcohol and ascertained the conditions for the formation of linear polymers consisting of six‐membered cyclic repeating units connected by methylene groups. Polymerization of asymmetric diene monomers was investigated using as examples vinyl crotonate, bulk polymerization of equimolecular quantities of allyl alcohol and maleic anhydride, and copolymerization of maleic anhydride with dibenzalactone. The establishment of the possibility of divinylacetal polymerization according to a cyclic mechanism makes it possible to outline new ways of synthesis of the acetals of polyvinyl alcohol. It has also been found that in the polymerization of the asymmetric diene monomers vinylcrotonate and monoallyl maleate, soluble, linear polymers are formed, of which the properties indicate that cyclization takes place in the course of the reaction.

Separation and Identification of Fatty Acids

For the characterization of fatty acids, 2, 4-dinitrophenylhydrazones of p-bromophenacyl esters of even-numbered saturated fatty acids from C2 to C20 and several unsaturated fatty acids from monoethenoid to triethenoid were prepared. The derivatives of linoleic and linolenic acids as well as those of the other unsaturated and saturated acids, were successfully obtained in crystalline forms which showed sharp and high melting points, 72° and 69°, respectively. It was found that the derivatives of unsaturated acids were valuable for characterizing the parent acids, while those of saturated acids were unsuitable for this purpose owing to the similarity of their melting points. By reversed-phase paper chromatography, the simultaneous separations of all saturated and unsaturated fatty acids were successfully carried out on the same paper with the aid of p-bromophenacyl ester 2, 4-dinitrophenylhydrazones and their mercuric acetate addition compounds. When petroleum hydrocarbon (b. p. 140–170°) was used as the stationary solvent and methanol—acetic acid—petroleum hydrocarbon as the moving solvent, even saturated acids from C4 to C22, even monoethenoid acids from C10 to C22, and C18 series from stearic to linolenic were well separated, respectively. Similar separations were also attained on paper impregnated with decalin and olive oil. From the results of several applications, this method has been found to be effective for the analysis of the component acids in natural fats.

Separation and Identification of Fatty Acids

For the characterization of fatty acids, 2, 4-dinitrophenylhydrazones of p-bromophenacyl esters of even-numbered saturated fatty acids from C2 to C20 and several unsaturated fatty acids from monoethenoid to triethenoid were prepared. The derivatives of linoleic and linolenic acids as well as those of the other unsaturated and saturated acids, were successfully obtained in crystalline forms which showed sharp and high melting points, 72° and 69°, respectively. It was found that the derivatives of unsaturated acids were valuable for characterizing the parent acids, while those of saturated acids were unsuitable for this purpose owing to the similarity of their melting points.