Condensation Of Acetone Research Articles

Chemical reactivity of the tryptophan/acetone/DMSO triad system and its potential applications in nanomaterial synthesis.

Previously, we reported a novel browning reaction of amino acids and proteins in an organic solvent mixture composed of dimethyl sulfoxide (DMSO) and acetone. The reaction proceeds under surprisingly mild conditions, requiring no heating or additional reactants or catalysts. This present study aimed to investigate the chemical reactivity of the triad reaction system of l-tryptophan/aectone/DMSO. We demonstrated that, in DMSO, l-tryptophan initially catalyzed the self-aldol condensation of acetone, resulting in the formation of mesityl oxide (MO). Furthermore, we showed that the three-component system evolved into a diverse chemical space, producing various indole derivatives with aldehyde or ketone functional groups that exhibited self-assembling and nanoparticle-forming capabilities. We highlight the potential applications in nanomaterial synthesis.

Talc modified by milling and alkali activation: Physico-chemical characterization and application in base catalysis

The work aimed at the development of benign solid base catalysts as alternatives for presently used noxious liquid bases. Talc, possessing intrinsic basic properties, was chosen as a particularly attractive and cost-effective precursor. Activation of talc by grinding in a planetary mill followed by treatment with 2 M NaOH was employed as means for basicity enhancement. Such protocol enabled profound modification of talc structure, otherwise resistant to treatment with a basic solution. Deep changes, not addressed in the literature reports so far, took place in the course of combined mechanical and alkali treatment. The amorphized ground talc transformed to the magnesium silicate hydrate (MSH) phase and brucite. Treatment with NaOH led to significant enhancement of surface basicity with respect to the parent materials. The effect was particularly spectacular for alkali-treated, strongly ground talc samples, containing the MSH component. The materials were tested in a base-catalyzed reaction of aldol condensation of acetone. The trend of catalytic activity followed closely the order of surface basicity, which pointed to the key role of MSH as a catalytically active phase in the modified talc solids. Joint mechanical and alkali activation of talc proved to be a simple, yet promising way of developing solid base materials for catalytic applications.

Reactivity of Formaldehyde during 4-Hydroxy-2-butanone Synthesis in Supercritical State.

4-Hydroxy-2-butanone, an important intermediate for vitamin A and fragrances, is usually produced by aldol condensation of acetone and formaldehyde. Noncatalytic synthesis of 4-hydroxy-2-butanone in supercritical state, which was fast and had high production yield, was widely applied. Previous research on 4-hydroxy-2-butanone synthesis in the supercritical state focused on the formation and dehydration of 4-hydroxy-2-butanone while ignoring side reactions involving formaldehyde, which were studied in this paper. A reaction pathway of 4-hydroxy-2-butanone supercritical synthesis containing formaldehyde side reactions was proposed. The cross-disproportionation of formaldehyde and formic acid was found to be the main consumption of formic acid. The effects of initial formaldehyde and formic acid mass fractions in the feed on side reactions were studied. Based on the experiments conducted from 523.15 K to 563.15 K and 17 MPa, a kinetic model was suggested. The relative deviations between experimental and simulated data were less than 10%.

Structure and Catalytic Properties of Magnesium Stannate in the Acetone Condensation Reaction

Structure and Catalytic Properties of Magnesium Stannate in the Acetone Condensation Reaction

Acetone Factor in the Design of Cu4-, Cu6-, and Cu9-Based Cage Coppersilsesquioxanes: Synthesis, Structural Features, and Catalytic Functionalization of Alkanes

The present study describes a new feature in the self-assembly of cagelike copperphenylsilsesquioxanes: the strong influence of acetone solvates on cage structure formation. By this simple approach, a series of novel tetra-, hexa-, or nonacoppersilsesquioxanes were isolated and characterized. In addition, several new complexes of Cu4 or Cu6 nuclearity bearing additional nitrogen-based ligands (ethylenediamine, 2,2'-bipyridine, phenanthroline, bathophenanthroline, or neocuproine) were produced. Single-crystal X-ray diffraction studies established molecular architectures of all of the synthesized products. Several coppersilsesquioxanes represent a novel feature of cagelike metallasilsesquioxane (CLMS) in terms of molecular topology. A Cu4-silsesquioxane complex with ethylenediamine (En) ligands was isolated via the unprecedented self-assembly of a partly condensed framework of silsesquioxane ligands, followed by the formation of a sandwich-like cage. Two prismatic Cu6 complexes represent the different conformers─regular and elliptical hexagonal prisms, "cylinders", determined by the different orientations of the coordinated acetone ligands ("shape-switch effect"). A heterometallic Cu4Na4-sandwich-like derivative represents the first example of a metallasilsesquioxane complex with diacetone alcohol ligands formed in situ due to acetone condensation reaction. As a selected example, the compound [(Ph6Si6O11)2Cu4En2]·(acetone)2 was explored in homogeneous oxidation catalysis. It catalyzes the oxidation of alkanes to alkyl hydroperoxides with hydrogen peroxide and the oxidation of alcohols to ketones with tert-butyl hydroperoxide. Radical species take part in the oxidation of alkanes. Besides, [(Ph6Si6O11)2Cu4En2]·(acetone)2 catalyzes the mild oxidative functionalization of gaseous alkanes (ethane, propane, n-butane, and i-butane). Two different model reactions were investigated: (1) the oxidation of gaseous alkanes with hydrogen peroxide to give a mixture of oxygenates (alcohols, ketones, or aldehydes) and (2) the carboxylation of Cn gaseous alkanes with carbon monoxide, water, and potassium peroxodisulfate to give Cn+1 carboxylic acids (main products), along with the corresponding Cn oxygenates. For these reactions, the effects of acid promoter, reaction time, and substrate scope were explored. As expected for free-radical-type reactions, the alkane reactivity follows the trend C2H6 < C3H8 < n-C4H10 < i-C4H10. The highest total product yields were observed in the carboxylation of i-butane (up to 61% based on i-C4H10). The product yields and catalyst turnover numbers (TONs) are remarkable, given an inertness of gaseous alkanes and very mild reaction conditions applied (low pressures, 50-60 °C temperatures).

Formation of the CaSnO3 crystalline phase during catalytic aldol condensation of acetone under supercritical conditions

Formation of the CaSnO3 crystalline phase during catalytic aldol condensation of acetone under supercritical conditions

Catalytic aldol condensation of bio-derived furanic aldehydes and acetone: Challenges and opportunities

Bio-derived furfural and 5-hydroxymethylfurfural can be combined with acetone to yield aldol condensation products that may serve as biofuel and polymer precursors. We have explored different catalytic systems to obtain and purify each product in the most efficient way. The results of the catalytic tests of the cross-condensations and of the self-condensation of acetone allowed the comparison of the different reactivity of the two aldehydes. Online and in situ/operando ATR-IR was used to monitor the reaction over time and to study the interaction of the reaction species with the solid catalyst, especially the formation of deactivating organic matter that covers the surface, which is a major issue in heterogeneous condensation processes. In situ NMR was used to study the ongoing reaction, assessing its stereoselectivity, and to study the behavior of deuterated species in the catalytic system. Finally, the preparation of C14, a hetero-double-condensation product, was also explored.

Structural Exploration and Protein Binding Efficiencies of Binuclear Dioxidomolybdenum(VI) Complexes Constructed from ONO Chelator and Linear N−N Ditopic Spacer

Binuclear dioxido Mo(VI) complexes(1 and 2) of general formula [(MoO2L1−2)2(bpe)] have been synthesized by varying a auxiliary bridging ligand on the primary ligand framework. The impact of spacer variation on metal-organic supramolecular architectures, DFT calculations and BSA binding efficiencies of the complexes has been studied. The intermolecular interactions in the crystal structures are also studied by Hirshfeld surface analysis. FRET, Time-resolved fluorescence measurement and molecular docking of the complexes were also carried out.

Catalytic Performance of Microporous and Hierarchical Zeolites in Condensation of Acetone with Ammonia

Catalytic Performance of Microporous and Hierarchical Zeolites in Condensation of Acetone with Ammonia

Consequences of Intrapore Liquids on Reactivity, Selectivity, and Stability for Aldol Condensation Reactions on Anatase TiO2 Catalysts

AbstractThis study provides evidence and mechanistic interpretations for the significant consequences of intrapore non‐polar liquids on acetone aldol condensation turnover rates, selectivity to primary dimer products, and catalyst stability for reactions at Lewis acid‐base site pairs on TiO2 surfaces. These non‐polar liquids confer such benefits through the preferential stabilization of transition states (TS) for adsorption (“entry”) and desorption (“exit”) steps, which place their respective reactants or products within a solvating outer sphere environment. The extent to which non‐polar fluids (n‐heptane) form an intrapore liquid phase within TiO2 voids was obtained from N2 uptakes using established formalisms that consider the different molal volume, surface tension, and volatility between N2 and n‐heptane. Acetone condensation rates are limited by C−H activation, an “entry” step that forms bound prop‐1‐en‐2‐olates via a TS stabilized by intrapore liquids, leading to higher aldol condensation turnover rates as n‐heptane pressure increases and active TiO2 surfaces become increasingly immersed within a non‐polar liquid phase. These liquids solvate the late TS structures that mediate the desorption of primary C6 condensation products even more effectively than those involved in prop‐1‐en‐2‐olate formation or in nucleophilic attack events that later form C−C bonds. Such preferential solvation favors desorption over C−C coupling events, thus disfavoring the formation of larger oligomers that become stranded at active sites, thus leading to much slower deactivation. Moreover, solvation by non‐polar liquids also leads to C6 alkanones as the sole products formed in a single surface sojourn. These effects of a non‐polar dense phase circumvent the inherent stability, reactivity, and selectivity hurdles that have precluded practical aldol condensation catalysis on Lewis acid‐base pairs at oxide surfaces; these consequences are demonstrated here for TiO2 catalysts, acetone aldol condensation reactions, and n‐heptane as the non‐polar liquid but through strategies, concepts, and mechanistic features that extend to other systems. More generally, these observations and their mechanistic origins demonstrate how a contacting liquid preferentially solvates TS structures for elementary steps that involve either reactants arriving from or products entering into an outer sphere environment that contains a dense non‐polar phase.

Copper Supported on Ceria Mesocellular Foam Silica as an Effective Catalyst for Reductive Condensation of Acetone to Methyl Isobutyl Ketone.

Copper-containing materials based on Ce- and Ca-Nb-mesocellular foam (MCF) silica supports are prepared, characterized and applied as catalysts for gas-phase reductive condensation of acetone to produce methyl isobutyl ketone (MIBK). The properties of the materials, the interaction of metal species, and their role in the catalytic process are examined by nitrogen physisorption, XRD, XPS, CO2 -TPD, H2 -TPR, and chemisorption of NO and pyridine combined with FTIR spectroscopy. A synergistic interaction of Cu2+ , Cu0 , and CeO2 species incorporated in the MCF support enable the Cu/Ce-MCF catalyst to yield 34 % of acetone conversion with over 90 % MIBK selectivity at 250 °C. Moreover, this high catalyst selectivity is maintained during operation for 24 h despite a decline in catalyst activity. The catalytic performance is superior to that of hydroxyapatite-supported Cu and similar previously reported Pd-containing catalysts.

Value addition of lignin to zingerone using recyclable AlPO4 and Ni/LRC catalysts

Value-addition of lignin to chemicals and medicinal compounds is highly desirable for bio-refineries and chemical industries. We present a simple and intriguing two-step method for synthesizing zingerone from vanillin. The first step was to make dehydrozingerone via aldol condensation of vanillin and acetone in the presence of an AlPO4 catalyst. At 120 °C for 24 h, this catalyst showed outstanding activity, with 99% selectivity of dehydrozingerone. Second, utilizing lignin residual carbon assisted Ni nanocatalyst (Ni/LRC), the dehydrozingerone was transformed into targeted zingerone by selective hydrogenation of the C–C double bond. The reaction parameters significantly influenced the formation of both dehydrozingerone and zingerone. The Physico-chemical properties of both the catalysts (AlPO4 and Ni/LRC) were thoroughly investigated by NH3 and CO2 TPD, Py-FTIR, XRD, N2 adsorption–desorption, 27Al, and 31P MAS NMR and FT-IR analysis. Interestingly, both AlPO4 and Ni/LRC catalysts were effectively recovered and reused for 10 cycles without apparent loss in catalytic activity for their respective reactions. Zingerone was eventually synthesized directly from lignin for the first time, with yields of 9.25 wt% on initial lignin intake.

Cooperativity in the Aldol Condensation Using Bifunctional Mesoporous Silica-Poly(styrene) MCM-41 Organic/Inorganic Hybrid Catalysts.

This work explores the efficacy of silica/organic hybrid catalysts, where the organic component is built from linear aminopolymers appended to the silica support within the support mesopores. Specifically, the role of molecular weight and polymer chain composition in amine-bearing atom transfer radical polymerization-synthesized poly(styrene-co-2-(4-vinylbenzyl)isoindoline-1,3-dione) copolymers is probed in the aldol condensation of 4-nitrobenzaldehyde and acetone. Controlled polymerization produces protected amine-containing poly(styrene) chains of controlled molecular weight and dispersity, and a grafting-to thiol-ene coupling approach followed by a phthalimide deprotection step are used to covalently tether and activate the polymer hybrid catalysts prior to the catalytic reactions. Site-normalized batch kinetics are used to assess the role of polymer molecular weight and chain composition in the cooperative catalysis. Lower-molecular-weight copolymers are demonstrated to be more active than catalysts built from only molecular organic components or from higher-molecular-weight chains. Molecular dynamics simulations are used to probe the role of polymer flexibility and morphology, whereby it is determined that higher-molecular-weight hybrid structures result in congested pores that inhibit active site cooperativity and the diffusivity of reagents, thus resulting in lower rates during the reaction.

Structural and evolutionary analysis unveil functional adaptations in the promiscuous behavior of serum albumins

Promiscuous activities have been related to the capacity to catalyze reactions different from those a protein has evolved to sustain. In this work, we rethought the serum albumin's promiscuous behavior using evolutionary and structural analysis. We found that the cross aldol condensation of acetone and p-formylbenzonitrile is a promiscuous reaction conserved in humans serum albumin and in closely related albumins from other mammals. Evolutionary analysis indicates that the residues involved in this promiscuous reaction are evolving under positive selection, an evolutionary pattern indicating a putative functional adaptation. Also, key residues are located in an evolutionary conserved cavity connected with the protein surface with an also conserved tunnel and mutations involving these residues are described in human diseases. Overall, our results suggest that albumin could have evolved to sustain a still unknown biological function among the many others it maintains. Our results could contribute to better characterize the serum albumin family and raise questions about the evolution of protein promiscuity and function.

Enhancing β-hydroxy ketone selectivity in the aldol condensation of furfural and acetone over N–B–O sites in calcined boron nitride

Air-calcined BN can catalyze the aldol reaction of furfural and acetone while suppressing dehydration to afford β-hydroxy ketone. Two types of O-substituted N defect sites were identified and a B-centered Lewis acid-catalyzed mechanism was proposed.

Synthesis, Spectroscopic Characterization, and Anticancer Activity of Metal Complexes with a Novel Schiff Base Ligand from -Diketone Derivatives

A new series complexes of Ni(II), Mn(II), Co(III), Cu(II), Cr(II), Zn(II), Zr(IV), Cd(II), and La(III) prepared by the reaction of the metal salt with a new Schiff base ligand. This Schiff base obtained by the condensation of p-phenylenediamine, 4-chlorobenzaldehyde, and acetyl acetone. The confirmation of the ligand and its metal complexes were characterized by multiple techniques such as, elemental analyses, magnetic susceptibility studies, FTIR 1H, 13C-NMR, XRD, molar conductance, UV-vis spectral analyses, and thermal analyses. The conductivity measurements of the complexes in DMF solutions indicated that the prepared complexes are nonelectrolytes. From the spectral data, an octahedral geometry was suggested for all complexes. The metal complex [(L)2Zr(Cl)2].3H2O showed the highest antifungal activity. The complexes [(L)(HL)Co(Cl)2].3H2O, and [(L)2Cd(H2O)2] showed antibacterial activities higher than the other complexes. All complexes are exhibited potent fungicides and bactericides than the ligand. Complex [(L)2Cd(H2O)2] exhibited considerable cytotoxicity against PC-3, SKOV3, and HeLa cells. The ligand C18H17N2OCl (HL) showed strong toxicity towards PC-3, HeLa cells, and moderate toxicity against SKOV3 cells.

Thermal and mechanical properties of polymer networks prepared by the thiol-ene reaction of a vanillin/acetone condensate and its related compounds

• Vanillin and benzaldehyde condensates with acetone were cured with a tetrathiol, S4P. • A diallylated vanillin/acetone condensate (DADVAT) was cured with S4P. • Radical-initiated photo/thermal cure and thermal cure using Et 3 N were investigated. • Photo/thermal dual cured DADVAT/S4P 1/1 exhibited excellent physical properties. • The thiol-ene reaction of the enone/thiol groups was promoted by the basic catalyst. A new bio-based diallyl compound, DADVAT, was synthesized by the allylation of 2,5-bis(4-hydroxy-3-methoxybenzylidene)acetone (DVAT), which had been prepared by the cross-aldol condensation of vanillin and acetone. The radical-initiated photothermal thiol–ene reactions of DADVAT/pentaerythritol tetrakis(3-mercaptopropionate) (S4P) at feed molar ratios of 1/1 and 2/1, DVAT/S4P, and trans,trans -dibenzylidene acetone (DBAT)/S4P at a molar ratio of 2/1 produced bio-based polymer networks (ptDADVAT-S4P-11, ptDADVAT-S4P-21, ptDVAT-S4P-21, and ptDBAT-S4P-21). The thermal and mechanical properties of the dual cured polymer networks were compared with those of thermally cured products (tbDADVAT-S4P-21 and tbDBAT-S4P-21) at a molar ratio of 2/1 using triethylamine as a basic catalyst for the nucleophilic thiol–ene reaction. ptDADVAT-S4P-11 displayed excellent thermal and mechanical properties compared to the other cured products. tbDADVAT-S4P-21 and tbDBAT-S4P-21 exhibited better thermal and mechanical properties than ptDADVAT-S4P-21 and ptDBAT-S4P-21, respectively, because the thiol–ene reaction of the enone and thiol groups is promoted by the basic catalyst rather than the radical initiators.

Dropwise condensation of acetone and ethanol for a high-performance lubricant-impregnated thermosyphon

A gravity-assisted heat pipe called a two-phase closed thermosyphon (TPCT) is an efficient thermal device that transfers a large amount of heat at a relatively small temperature difference using the phase-change process. Promoting dropwise condensation on a condenser wall of a TPCT promises an increase in the effective thermal conductance of that device. Acetone and ethanol have been widely used for heat pipe applications as working fluids. Still, they pose a limitation in promoting dropwise condensation using typical hydrophobic coatings due to their lower surface energies. Recent works have shown that lubricant-impregnated surfaces (LIS) can promote dropwise condensation of low-surface-tension fluids, but no studies proved the effectiveness of the surfaces in TPCT applications. This study experimentally achieves dropwise condensation of acetone and ethanol within a TPCT using the LIS surface. We demonstrate heat transfer enhancement of a TPCT by examining temperature uniformity, condenser and evaporator heat transfer coefficients (HTCs), and overall and partial thermal resistances. We demonstrated that the LIS condenser increased the condenser HTC by 220% and decreased the overall thermal resistance of the TPCT by 44% compared to filmwise condensation. Our work also revealed a strong dependence of working fluid viscosity on dropwise condensation stability and heat transfer enhancement by comparing the two working fluids, acetone, and ethanol. This work presents the opportunity for improving thermal performance in heat pipes and applications that rely on the condensation of low-surface-tension fluids, such as HVAC, refrigeration, and organic Rankine cycle.

Solvent-free aldol condensation of furfural and acetone on calcined Mg-Al hydrotalcites

Une serie de materiaux de type hydrotalcite Mg X Al-CO 3 , ou X correspond au rapport molaire nominal Mg / Al (X: 2, 2,5, 3 et 3,5), ont ete prepares et caracterises par fluorescence X (XRF ), X - diffraction des rayons (XRD), spectroscopie infrarouge (FT-IR) et analyse thermique (TG-DTA). L'oxyde mixte (Mg X Al-O) avec un rapport Mg / Al de 3,5 derive de l'hydrotalcite calcinee a 450 ° C s'est avere etre le catalyseur optimal qui peut donner la basicite la plus elevee et la plus grande activite catalytique pour la condensation aldolique sans solvant du furfural et de l'acetone. L'activite des hydrotalcites de Mg-Al calcine pour cette reaction etait correlee a leur basicite telle que determinee par l'adsorption de phenol. La meilleure conversion du furfural et la selectivite du furfural-acetone (FA) ont ete obtenues a 90 ° C apres 2 heures sur le Mg 3,5 Al-O avec 98% de conversion et une selectivite de 78% en (FA). L'activation pour la condensation d'aldol entre le furfural et l'acetone s'est averee etre de 24,8 KJ / mol en catalyze heterogene avec des hydrotalcites de Mg-Al calcine par rapport a la valeur augmentee en catalyze homogene avec NaOH qui etait de 55,8 KJ / mol.

Radical transformations of organic solvents under sub- and supercritical conditions

A comparative study of chemical transformations of ethanol, acetone and dimethyl carbonate was performed in a temperature range from 200 to 300 °C. These compounds are widely used as solvents for processing vegetable raw materials. Therefore, knowing their behaviour in a reaction medium is necessary to understand the mechanism of sub- and supercritical extraction of the vegetable raw materials and the role of solvents in this processуы. It was established that the investigated compounds under certain conditions function as a source of free radicals; thus, they can contribute to the radical decomposition of the major components in plant biomass. The Schwarz toluene method was used to detect free radicals in reaction media. It is shown that radical breakdown of bonds in the acetone and dimethyl carbonate molecules occurs already at a temperature of 200 °C, and in ethanol - only under supercritical conditions at temperatures over 250 °C. Alkylation is the main reaction occurring during the thermal treatment of toluene and solvents mixtures, which leads to a high yield of various alkylbenzenes for all investigated xylene solvents. In a temperature range from 200 to 250 °С, acetone has the highest alkylating capability and ethanol - the lowest one. At temperatures above 250 °С, the alkylating capability of solvents is similar, with a slight prevalence of that of dimethyl carbonate. Unlike other solvents, acetone participates in nucleophilic addition reactions along with radical transformations under process conditions. The products obtained as a result of these reactions at temperatures above 250 °C are predominant. The main ones are the products of the aldol and crotonic condensation of acetone. Based on the results of a study, the pathways of the radical decomposition of solvents molecules and the formation of products of thermal treatment were proposed.