Acetylenic Alcohols Research Articles

DABCO[sbnd]Catalyzed Tandem Si–Csp-Desilylation–Addition Reactions of 3-Trimethylsilyl-2-propynamides with Acetylenic Alcohols and Diols: Synthesis of β-(Propargyloxy)acrylamides

A number of previously unknown amide-containing propargyl vinyl ethers has been synthesized in a total yield of 54–92 % by DABCO-catalyzed, tandem desilylation–addition reactions of 3-trimethylsilyl-2-propynamides with acetylenic alcohols and diols. The effect of substituents at the triple bond in acetylenic alcohol (diol) and at the nitrogen atom in amides on the reaction outcome is studied.

Effectiveness of ethynylcyclohexanol and methyl-tert-amyl ether in increasing the octane number of gasoline compositions

The purpose of this study is to systematically compare the octane-enhancing properties of the novel tertiary acetylenic alcohol (TAA) ethinylcyclohexanol (ECH) with the conventional ether methyl-tert-amyl ether (MTAE) as a gasoline additive. ECH was synthesized using a modified Favorsky reaction and blended with gasoline compositions containing varying ratios of straight-run, delayed coking, and catalytic reforming fractions. The octane number was measured using a SHATOX SX-100K octanometer. The results indicate that ECH provides significantly higher boosts in research and motor octane numbers compared to MTAE for all blend compositions tested, even at high reformate content where knock resistance becomes less sensitive to oxygenates. The comparison shows that ECH has a superior octane response compared to MTAE, indicating its potential as an alternative gasoline octane booster.

Influence of Phosphorus Modifier and Nature of the Support on the Properties of Palladium Catalysts in the Chemoselective Hydrogenation of Acetylenic Compounds

Efficient heterogeneous catalysts for the chemoselective hydrogenation of terminal and disubstituted alkynes and alkynols to monoenes based on Pd–P particles have been proposed. The influence of a zeolite support (Na-ZSM-5, MCM-41) and a phosphorus modifier on the properties of palladium catalysts in the semihydrogenation of acetylenic compounds is considered. It has been shown that promotion with phosphorus increases the activity of palladium catalysts in the hydrogenation of various acetylenic compounds from 2.5 to 30 times without reducing the selectivity for monoenes. High selectivity for monoenes is determined by both thermodynamic and kinetic factors. Using the example of the acetylenic alcohol hydrogenation the possibility of changing the ratio of hydrogenation rates of triple and double bonds as a result of varying the solvent nature and the structural order of the catalyst particles was demonstrated.

Efficiency of oxygenates on increase of octane number of reforming gasoline

At present, gasoline occupies one of the leading places among primary energy sources. The need of mankind in it, in its high quality, is greater than in any other fraction of hydrocarbons. Therefore, very high requirements are made to the operational properties of automobile gasoline, and the problem of improving the quality of gasoline is one of the urgent problems of the chemical industry. Modern vehicles require fuel with a high-octane number with properties preventing detonation and having octane numbers of 92, 95 and 98 for engines. High anti-detonation performance can be achieved through complex gasoline processing using catalytic cracking, isomerization and alkylation methods or by adding special high-octane additives to fuel. The world's leading trend in improving the environmental and performance characteristics of motor gasoline is the use of multifunctional additives, in particular oxygenates – compounds containing oxygen (such as alcohols, ketones, esters and others). The use of oxygen-containing components (oxygenates) is one of the promising ways to produce high-octane gasoline. Currently, in industrialized countries, oxygenates are actively used as a preferred substitute for organometallic anti-detonation additives and components of high-octane gasoline. In the presented work the properties of a new oxygenate - dimethyl ethynylcarbinol (DMEC), as an additive that increases the octane number of gasoline, are investigated. The study of the effect of oxygenates as methyl tert-butyl ether (MTBE) and DMEK on increasing the octane number of reforming gasoline showed that the increase in the octane number of gasoline when adding DMEK and binary additive is higher than when adding MTBE. According to the results of research, tertiary acetylene alcohol - DMEK can be offered as an oxygen-containing additive for automobile gasoline. The use of DMEK allows to expand the resources of high-octane components, reduce the toxicity of gasoline and exhaust gases, increase the production of high-quality commercial gasoline for automotive engines.

Visible-light-mediated O–H functionalization reactions of acetylenic alcohols with 3-diazooxindoles: Facile access to spirooxindole-fused oxacycles

Visible-light-mediated O–H functionalization reactions of acetylenic alcohols with 3-diazooxindoles were first described. Various substituted acetylenic alcohols were well tolerated and the O–H functionalization products were delivered in moderate to high yields. More importantly, these ether products could be easily transformed into spirooxindole-fused oxacycles. A preliminary study of the mechanism revealed that this reaction probably proceeded through a carbene transfer instead of a proton transfer pathway.

Semi‑hydrogenation of acetylenic alcohol to olefinic alcohol catalyzed by Pd nanoparticles embedded in nitrogen-enriched porous carbon derived from ZIF-8

Semi‑hydrogenation of acetylenic alcohol to olefinic alcohol catalyzed by Pd nanoparticles embedded in nitrogen-enriched porous carbon derived from ZIF-8

A facile, regio and diastereoselective synthesis of functionalized azetidin-2-ones: Cu(I) mediated Kinugasa reaction of functionalized nitrones with acetylenic alcohols

The manuscript presents an efficient method for the synthesis of various cis-azetidin-2-ones with high regio- and diastereoselectivity. This approach utilizes Kinugasa reaction involving diverse functionalized nitrones, including diaryl nitrones and α,β-unsaturated nitrones, in conjunction with acetylenic alcohols. Copper (I) serves as a catalyst to facilitate the transformation.

Research of the synthesis of new acetylene aminoalcohols

The article describes the synthesis of acetylene amino alcohols based on secondary acetylene alcohol and amino compounds containing a hydroxyl group, the results of scientific research and their analysis to study the influence of factors such as temperature and catalyst on the yield of the product in the process. In the course of the work, a new type of acetylene amino alcohol was obtained with high efficiency as a result of the condensation reaction of ethanolamine (or diethanolamine) with hex-1-yn- 3-ol mediated by formaldehyde. Optimal conditions for carrying out synthesis processes have been determined. The mechanism of these chemical processes is explained on the basis of theoretical quantum chemical calculations of the reactivity of the starting substances.

Visible-Light-Enabled Catalytic Approach to N,O-Spirocycles through Amidyl Radical Addition/Cyclization.

A rational combination of photoredox catalyst anthraquinone and hydrogen atom transfer (HAT) catalyst methyl thioglycolate allows for the rapid and straightforward conversion of a range of 2-amidated acetylenic alcohols to multifunctional N,O-spirocycles under visible light irradiation. With oxygen as the sole terminal oxidant, these reactions can be carried out efficiently at room temperature without the involvement of transition metals or strong oxidants. The successful application of this mild catalytic strategy in the late-stage functionalization of bioactive skeletons further highlights its practical value.

Flotation of copper-zinc ores using reagents based on acetylene alcohols

Flotation of copper-zinc ores using reagents based on acetylene alcohols

Application of Metal-Based Catalysts for Semi-Hydrogenation of Alkynol: A Review

Alkynol semi-hydrogenation plays a vital role in industrial processes, due to the significance of its main product, enol, in high-end chemical synthesis, such as medicine, pesticide, food additives, and polymer monomer synthesis. Multiple intermediates are formed through a complex series of parallel or continuous reactions under varying conditions. However, the selectivity and efficiency of catalysts for producing these products still pose significant challenges. This review aims to thoroughly discuss the challenges and advancements in catalysts using different species and supports under various reaction conditions. Furthermore, strategies to enhance the yield and rate of enols are summarized based on noble metals, non-noble metals, and metal comparisons. By addressing diverse catalysts and reaction conditions, this review provides valuable insights into improving the semi-hydrogenation of acetylenic alcohols to enols.

The Effect of Polymer Matrix on the Catalytic Properties of Supported Palladium Catalysts in the Hydrogenation of Alkynols

Palladium catalysts were obtained by the adsorption method involving the sequential deposition of polyvinylpyrrolidone (PVP) and then palladium ions on a modified zinc oxide surface without high-temperature calcination and reduction stages. The immobilized PVP-palladium catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), infrared spectroscopy (IRS), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and elemental analysis methods. It was found that the introduction of polymer into the catalyst’s composition promotes the dispersion and uniform distribution of active phase nanoparticles (PdO, Pd0) on the surface of zinc oxide. The catalysts were tested in the hydrogenation of complex acetylene alcohol, 3,7,11-trimethyldodecyn-1-ol-3 (C15-yn) under mild conditions (0.1 MPa, 40 °C). For comparison, studies on stereoselective hydrogenation of the short-chain alcohol 2-hexynol-1 were performed. It was shown that modification of the catalyst with polymer improves its catalytic properties. High C15-alkenol selectivity (98%), activity (W = 70 × 10−6 mol/s), and stability (turnover number (TON) 62,000) were achieved on a Pd-PVP/ZnO catalyst. Varying the active phase made it possible to reduce the metal content without deteriorating the catalytic performance of the catalyst.

Unexpected Decarbonylation of Acylethynylpyrroles under the Action of Cyanomethyl Carbanion: A Robust Access to Ethynylpyrroles.

It has been found that the addition of CH2CN- anion to the carbonyl group of acylethynylpyrroles, generated from acetonitrile and t-BuOK, results in the formation of acetylenic alcohols, which undergo unexpectedly easy (room temperature) decomposition to ethynylpyrroles and cyanomethylphenylketones (retro-Favorsky reaction). This finding allows a robust synthesis of ethynylpyrroles in up to 95% yields to be developed. Since acylethynylpyrroles became available, the strategy thus found makes ethynylpyrroles more accessible than earlier. The quantum-chemical calculations (B2PLYP/6-311G**//B3LYP/6-311G**+C-PCM/acetonitrile) confirm the thermodynamic preference of the decomposition of the intermediate acetylenic alcohols to free ethynylpyrroles rather than their potassium derivatives.

Selective Hydrogenation of 2-Methyl-3-butyn-2-ol in Microcapillary Reactor on Supported Intermetallic PdZn Catalyst, Effect of Support Doping on Stability and Kinetic Parameters

The development of active, selective, and stable multicrystalline catalytic coatings on the inner surface of microcapillary reactors addresses environmental problems of fine organic synthesis, in particular by reducing the large quantities of reagents and byproducts. Thin-film nanosized bimetallic catalysts based on mesoporous pure titania and doped with zirconia, ceria, and zinc oxide, for use in microreactors, were developed, and the regularities of their formation were studied. The efficiency of PdZn/TixM1−xO2±y (M = Ce, Zr, Zn) in the hydrogenation of 2-methyl-3-butyn 2-ol was studied with an emphasis on the stability of the catalyst during the reaction. The catalytic parameters depend on the adsorption properties and activity of PdZn and Pd(0) active centers. Under reaction conditions, resistance to the decomposition of PdZn is a factor that affects the stability of the catalyst. The zinc-doped coating proved to be the most selective and stable in the reaction of selective hydrogenation of acetylenic alcohols in a microcapillary reactor. This coating retained a high selectivity of 98.2% during long-term testing up to 168 h. Modification of the morphology and electronic structure of the active component, by doping titania with Ce and Zr, is accompanied by a decrease in stability.

Click Chemistry of Selenium Dihalides: Novel Bicyclic Organoselenium Compounds Based on Selenenylation/Bis-Functionalization Reactions and Evaluation of Glutathione Peroxidase-like Activity

A number of highly efficient methods for the preparation of novel derivatives of 9-selenabicyclo[3.3.1]nonane in high yields based on selenium dibromide and cis,cis-1,5-cyclooctadiene are reported. The one-pot syntheses of 2,6-diorganyloxy-9-selenabicyclo[3.3.1]nonanes using various O-nucleophiles including alkanols, phenols, benzyl, allyl, and propargyl alcohols were developed. New 2,6-bis(1,2,3-triazol-1-yl)-9-selenabicyclo[3.3.1]nonanes were obtained by the copper-catalyzed 1,3-dipolar cycloaddition of 2,6-diazido-9-selenabicyclo[3.3.1]nonane with unsubstituted gaseous acetylene and propargyl alcohol. The synthesis of 2,6-bis(vinylsulfanyl)-9-selenabicyclo[3.3.1]nonane, based on the generation of corresponding dithiolate anion from bis[amino(iminio)methylsulfanyl]-9-selenabicyclo[3.3.1]nonane dibromide, followed by the nucleophilic addition of the dithiolate anion to unsubstituted acetylene, was developed. The glutathione peroxidase-like activity of the obtained water-soluble products was estimated and compounds with high activity were found. Overall, 2,6-Diazido-9-selenabicyclo[3.3.1]nonane exhibits the highest activity among the obtained compounds.

Interaction of Acetylenic Alcohols with the Coal’s Surface during Flotation

Interaction of Acetylenic Alcohols with the Coal’s Surface during Flotation

Functionalized Homologues and Positional Isomers of Rabbit 15- Lipoxygenase RS75091 Inhibitor.

RS75091 is a cinnamic acid derivative that has been used for the crystallization of the rabbit ALOX15-inhibitor complex. The atomic coordinates of the resolved ALOX15- inhibitor complex were later on used to define the binding sites of other mammalian lipoxygenase orthologs, for which no direct structural data with ligand has been reported so far. The putative binding pocket of the human ALOX5 was reconstructed on the basis of its structural alignment with rabbit ALOX15-RS75091 inhibitor. However, considering the possible conformational changes the enzyme may undergo in solution, it remains unclear whether the existing models adequately mirror the architecture of ALOX5 active site. In this study, we prepared a series of RS75091 derivatives using a Sonogashira coupling reaction of regioisomeric bromocinnamates with protected acetylenic alcohols and tested their inhibitory properties on rabbit ALOX15. A bulky pentafluorophenyl moiety linked to either ortho- or metha-ethynylcinnamates via aliphatic spacer does not significantly impair the inhibitory properties of RS75091. Hydroxylated 2- and 3-alkynylcinnamates may be suitable candidates for incorporation of an aromatic linker group like tetrafluorophenylazides for photoaffinity labeling assays.

Quantum-chemical substantiation of collecting properties of acetylene reagents in flotation of sulphide minerals

The paper presents the analysis results of known data and performed adsorption and spectral IR studies of MIG-4E, DMIPEK and DC-80 acetylene reagents in interaction with galena (PbS) and molybdenite (Mo2S) sulphide minerals. The IR spectra analysis of pure reagents and products of their interaction with the surface of sulphide minerals has showed that the adsorption of MIG-4E molecules takes place on the surface of lead sulphides, and DMIPEC molecules are adsorbed on the surface of molybdenite. Quantum-chemical calculations of the total potential energy of the complexes have shown that the complex formed by a molecule of MIG-4E – PbS of (HUMO) complexes by nucleophilic mechanism has 2514.0873 kcal/mol, which is almost an order of magnitude greater than the total potential energy (270.0439 kcal/mol) of MIG-4E – PbS (HUMO) complex formed by electrophilic mechanism. Analysis of the calculated data of the total potential energy of complexes formed by MIG-4E reagent molecules with PbS surface and DMIPEC molecules with Mo2S surface has showed that the total energy of π-complexes formed by reagents by electrophilic mechanism differs by 47.7% among reagent molecules and amounts to 270.0439 kcal/mol for (MIG-4E + PbS) complex, and 141.9386 kcal/mol for (DMIPEC + Mo2S) complex in the (HUMO) state. Such a difference in the values of total energies of the complexes can correlate with the conformational ability of DMIPEC reagent molecules. Usage of acetylene alcohols as additional selective collectors during flotation of a number of non-ferrous and precious metal ores has shown a significant increase in the extraction of target metals, which makes it possible to consider the reagents based on acetylene derivatives as promising for industrial applications.

Selective Catalytic Hydrogenation of Triple Bonds in Acetylenic Alcohols in a Microcapillary Reactor for Processes of Fine Organic Synthesis

Selective Catalytic Hydrogenation of Triple Bonds in Acetylenic Alcohols in a Microcapillary Reactor for Processes of Fine Organic Synthesis

Selective catalytic hydrogenation of the triple bond in acetylenic alcohols in a microcapillary reactor for fine organic synthesis

The purpose of this work is to present our latest achievements in the design, synthesis and development of a new catalytic microreactor for the processes of selective and continuous synthesis of substances with added value that are used in fine organic synthesis and pharmaceutical industries. In this advanced device, metal nanoparticles are embedded in mesoporous materials, which are deposited in the form of highly active and selective catalytic films on the walls of capillary microchannels with diameters of 220 and 530 μm. In such microreactor systems, there is no subsequent separation of the catalyst, which facilitates continuous operation. Potentially the most stable coatings are crystalline or amorphous titanium dioxide based metal oxides synthesized by the sol-gel method and containing embedded catalytically active polymetallic nanoparticles. The catalytic properties and operational stability of capillary microreactors were investigated at atmospheric pressure and compared with conventional industrial batch reactors. The developed Pd50Zn50 /TiO2 coating showed a higher activity (1.5 gMBE·gPd–1·s–1) and selectivity (96.7 %) in comparison with the coatings described earlier in the literature and with the industrial Lindlar catalyst, and retained high catalytic performance after 88 hours of reaction.