Carbonyl Compounds Research Articles

Synthesis of Propiolic and Butynedioic Acids via Carboxylation of CaC2 by CO2 under Mild Conditions

Carbon dioxide (CO2) is a greenhouse gas, and its resource use is vital for carbon reduction and neutrality. Herein, the nucleophilic addition reaction of calcium carbide (CaC2) to CO2 was studied for the first time to synthesize propiolic and butynedioic acids by using CuI or AgNO3 as catalyst, Na2CO3 as additive, and triphenylphosphine as ligand in the presence/absence of a hydrogen donor. The effects of the experimental conditions and intensification approach on the reaction were investigated. The reactivity of CaC2 is closely associated with its synergistic activation by the catalysts, solvent, and external intensification, such as the ultrasound and mechanical force. Ultrasound helps to promote the reaction by enhancing the interfacial mass transfer of CaC2 particulates. Mechanochemistry can effectively promote the reaction, yielding 29.8% of butynedioic acid and 74.8% of propiolic acid after 2 h ball milling at 150 rpm, arising from the effective micronization and interfacial renewal of calcium carbide. The present study sheds a light on the high-value uses of CO2 and CaC2 and is of reference significance for the nucleophilic reaction of CaC2 with other carbonyl compounds.

Urea for removing the aldehydes and ketones in leather VOCs and recycling performance of ethanol eluent

Hexanal, found in high-grade leather sofas, has a high odor activity value of 21285.8. Thus far, a method to remove hexanal from leather VOCs has not been reported. In this study, we developed a hexanal removal method that involves the elution of hexanal with an eluent of urea and ethanol (EtOH). We achieved the best hexanal removal rate with a urea concentration of 14 g/L, a liquid ratio of 75, a reaction time of 120 min, a temperature of 60 °C, an ultrasonic environment, and the presence of anhydrous CaCl2. The mechanism of hexanal removal by urea was confirmed via quartz crystal microbalance with dissipation monitoring, Fourier-transform infrared spectroscopy, and 1H NMR. Moreover, the EtOH eluent exhibited excellent recyclability over five cycles, where EtOH was distilled after every cycle and fresh eluent was prepared with the recycled EtOH. The physicochemical properties of the leather also remained unchanged after this treatment. Our strategy based on the Schiff base reaction between urea and carbonyl compounds can be extended to other aldehydes and ketones of leather VOCs to improve the air quality in leather environments.

Magnetically recoverable molybdate supported silica decorated ferrite nanocat (Fe–Si–Mo) and their utilization for reductive amination of carbonyl compound under benign condition

A magnetite silica-coated nanoparticle-supported molybdate catalyst (Nanocat-Fe-Si-Mo) was successfully prepared by simple co-precipitation techniques. The prepared nanoparticles have been characterized using FE-SEM, EDX, FT-IR, WDX, ICP-OES, TEM, and TGA techniques. Under benign conditions, the catalytic activity of the nanocatalyst was investigated for the reductive amination of carbonyl compounds; a greener methodology is presented that provides a simple and efficient technique for the production of secondary amine utilizing a recyclable nanocatalyst. Notably, 0.09 mg of the catalyst is adequate for the amination of carbonyl compound in the alcoholic medium at room temperature. Significantly, utilizing an external magnet, the nanoparticles have been readily removed among the solution with recovered a minimum of 10 times without losing catalytic activity.

A new sol-gel fluorescent sensor to track carbonyl compounds

Carbonyl compounds are ubiquitous quality trackers that provide information about food product degradation as well as air and water pollution levels. In addition, they are used as biomarkers for medical diagnoses. With more user-friendly sensors, their fast detection and easy quantification are highly relevant. The synthesis, characterization, and performance assessment of a new sensor based on aniline fluorescence to monitor carbonyls in real time is reported. A cost-effective synthesis using a straightforward sol-gel process led to the construction of a nontoxic silica-based material with high porosity, which can be used with almost no sample preparation. The material exhibits a rapid (< 1 min) fluorescence decrease upon interaction with carbonyl groups. The limit of detection is as low as ca. 5 × 10−4 mol·L−1 for hexanal, while fluorescence extinction occurs at much higher concentrations (5 × 10−1·mol L−1), which enables the sensor to be used with a very broad range of detection. Real-time monitoring is possible since the fluorescence loss correlates with the concentration of carbonyl moieties. The performance was validated in simulating as well as in real media, making this sensor suitable for use in a wide range of applications.

Modular Synthesis of Tetrasubstituted Vinyl Sulfides via One-Pot Sequential Carbene Transfer Reaction from Thiols with α-Diazo Carbonyl Compounds.

We present a one-pot reaction that offers an efficient approach to synthesizing tetrasubstituted vinyl sulfides with high stereoselectivity. This method involves the sequential Wolff rearrangement, ylide formation, and [1,4]-aryl transfer by utilizing aryl and alkyl thiols and α-diazo carbonyl compounds as substrates. Notably, this reaction features commercially available materials, straightforward operation, atom economy, and broad substrate scope. Moreover, the primary photophysical properties (aggregation-induced emission effect) of the products were also investigated, which might be useful in functional materials via structural modification.

Chromium Catalyzed Asymmetric Reformatsky Reaction

AbstractThis study describes an unprecedented chromium‐catalyzed asymmetric Reformatsky reaction, enabling the synthesis of chiral β‐hydroxy carbonyl compounds from α‐chlorinated or α‐brominated esters and amides. By employing a chiral chromium/diarylamine bis(oxazoline) catalyst, we achieved relatively broad functional group tolerance. Distinct from known reports, the protocol operates under both classical and photoredox conditions, facilitated by the in situ formation of a nucleophilic chiral chromium intermediate through a radical‐polar crossover mechanism. Preliminary mechanistic insights, supported by DFT calculations, identify the nucleophilic aldehyde addition as the key stereo‐determining step. This approach not only overcomes the limitations of existing Reformatsky reactions but also provides a versatile strategy for accessing complex chiral molecules.

Green Synthesis of Au‐Ag@TiO2 Nanocomposite for Photocatalytic Oxidation of Substituted Benzyl Alcohols

AbstractThe scaling‐up of methodologies in the oxidation of alcohols to carbonyl compounds faced widespread hindrance in industries due to large‐scale use of toxic and expensive metal oxidants. Novel, cost‐effective and eco‐friendly approaches need to be developed to address these problems. Bimetallic nanoparticles (BMNPs) show synergistic effects at atomic level, which makes them excellent catalysts for organic transformations. Transition metal nanocomposite with unique physicochemical properties and high surface area offers a promising alternative to traditional catalysts. Herein, an environment‐friendly methodology was adopted for the synthesis of Au−Ag BMNPs using phenolic‐rich Ocimum basilicum (L.) leaf extract, which was then incorporated into TiO2 matrix for the synthesis of plasmonic Au−Ag@TiO2 nanocomposite. The formation of the nanocomposite was confirmed through analytical characterizations, such as UV–Vis. DRS, FT‐IR, PL, SEM, TEM and XRD. The nanocomposite exhibited excellent catalytic activity in the selective oxidation of primary and secondary alcohols in aqueous media using H2O2 as an oxidant under visible light irradiation at room temperature. The nanocomposite also demonstrated good reusability of 84 % in the fifth cycle, which established its promising candidature for wide‐scale applications. This work holds significant relevance for industries dealing with pharmaceuticals and personal care products, and thus, offers sustainable solution for organic transformations.

Chromium Catalyzed Asymmetric Reformatsky Reaction.

This study describes an unprecedented chromium-catalyzed asymmetric Reformatsky reaction, enabling the synthesis of chiral β-hydroxy carbonyl compounds from α-chlorinated or α-brominated esters and amides. By employing a chiral chromium/diarylamine bis(oxazoline) catalyst, we achieved relatively broad functional group tolerance. Distinct from known reports, the protocol operates under both classical and photoredox conditions, facilitated by the in situ formation of a nucleophilic chiral chromium intermediate through a radical-polar crossover mechanism. Preliminary mechanistic insights, supported by DFT calculations, identify the nucleophilic aldehyde addition as the key stereo-determining step. This approach not only overcomes the limitations of existing Reformatsky reactions but also provides a versatile strategy for accessing complex chiral molecules.

MicroRNA-Dependent Mechanisms Underlying the Function of a β-Amino Carbonyl Compound in Glioblastoma Cells.

Glioblastoma (GB) is an aggressive brain malignancy characterized by its invasive nature. Current treatment has limited effectiveness, resulting in poor patients' prognoses. β-Amino carbonyl (β-AC) compounds have gained attention due to their potential anticancerous properties. In vitro assays were performed to evaluate the effects of an in-house synthesized β-AC compound, named SHG-8, upon GB cells. Small RNA sequencing (sRNA-seq) and biocomputational analyses investigated the effects of SHG-8 upon the miRNome and its bioavailability within the human body. SHG-8 exhibited significant cytotoxicity and inhibition of cell migration and proliferation in U87MG and U251MG GB cells. GB cells treated with the compound released significant amounts of reactive oxygen species (ROS). Annexin V and acridine orange/ethidium bromide staining also demonstrated that the compound led to apoptosis. sRNA-seq revealed a shift in microRNA (miRNA) expression profiles upon SHG-8 treatment and significant upregulation of miR-3648 and downregulation of miR-7973. Real-time polymerase chain reaction (RT-qPCR) demonstrated a significant downregulation of CORO1C, an oncogene and a player in the Wnt/β-catenin pathway. In silico analysis indicated SHG-8's potential to cross the blood-brain barrier. We concluded that SHG-8's inhibitory effects on GB cells may involve the deregulation of various miRNAs and the inhibition of CORO1C.

Carbonylation Reactions of a Metallapentalyne: Synthesis of Its Ester and Amide Derivatives

Comprehensive SummaryCarbonylation reactions are a valuable synthetic method to construct carbonyl compounds and carbonylation reactions of aryl halides stand out as a highly significant tool for generating carbonyl substituted arenes. However, the important reactions have never been realized in aromatic metallacycles. Herein, we present the first carbonylation reactions of metallaaromatics, specifically alkoxycarbonylation and aminocarbonylation reactions of an osmapentalyne. During the carbonylation process, the electronic and steric properties of nucleophiles are regarded as critical factors. The alcohols with bulky substituents (isopropanol) require more reaction time and tert‐butyl alcohol is inert in the reaction. Comparatively, amines, being stronger nucleophiles, exhibit divergent behaviors. Bulky amines undergo aminocarbonylation, whereas small amines prefer direct nucleophilic additions. Control experiments revealed that the intermediate derived from coupling of metal carbyne with CO plays a significant role in the carbonylation reaction. According to these observations, a divergent pathway for the reaction is proposed. Furthermore, the photophysical properties of these carbonyl‐functionalized osmapentalene complexes are studied, and the maximum absorption peak of compound with a carboxylic group exhibits a significant red‐shift due to the smaller HOMO‐LUMO gap. These findings contribute to expanding the reactivity of metallaaromatics and offer new opportunities for the synthesis of carbonyl‐functionalized metallacycles.

A tutorial on solid-phase analytical derivatization in sample preparation applications

Solid-phase analytical derivatization is a versatile sample preparation technique that enhances analysis accuracy, efficiency, reproducibility, and sensitivity. The technique combines the advantages of analytical derivatization and solid-phase extraction, providing a versatile approach for analysing analytes with various functional groups in complex matrices. Analytical derivatization is a technique used for functional group analysis that involves modifying the structure of an analyte to enhance sensitivity and specificity. Solid-phase analytical derivatization is a one-pot procedure that combines analytical derivatization and extraction. In the presence of acids, it can derivatize phenols, carboxylic acids, and other analytes. Furthermore, solid-phase analytical derivatization increases the reaction rate of carbonyl compounds, making it easier to extract aldehydes and ketones rapidly. This technique utilises electrophoresis, chromophores, fluorophores, and functional groups for detection and extraction. It initially began as a batch procedure but has now developed into an automated, microextraction, and derivatization method. Solid-phase analytical derivatization is highly efficient due to the significant excess of the derivatizing reagent relative to the analyte, along with the pre-impregnation of derivatizing reagents, which can speed up the process compared to traditional solution-based derivatization. This tutorial aims to provide detailed insights into the practical aspects of implementing solid-phase analytical derivatization in analytical method development and discuss the prospects and future trends.

ATI Stabilized Germylene Cation as a Cyanosilylation Catalyst for Aldehydes and Ketones.

The aminotroponiminate (ATI) ligand stabilized germylene cation [(i-Bu)2ATIGe][B(C6F5)4] (2) is found to be an efficient low-valent main-group catalyst for the cyanosilylation of aldehydes and ketones (ATI=aminotroponiminate). It was synthesized by reacting [(i-Bu)2ATIGeCl] (1) with Na[B(C6F5)4]. The catalytic cyanosilylation of diverse aliphatic and aromatic carbonyl compounds (aldehydes and ketones) using 0.075-0.75 mol% of compound 2 was completed within 5-45 min. The catalytic efficiency seen with aliphatic aldehydes was around 15,800 h-1, making compound 2 a capable low-valent main-group catalyst for the aldehyde and ketone cyanosilylation reactions. Further, DFT calculations reveal a pronounced charge localization at the germanium atom of compound 2, leading to its superior catalytic performance.

Orange Juice: A Remarkable Green Catalyst for the Michael Addition Reaction of Indoles

Michael addition reaction is widely accepted as the most important reaction for making carbon-carbon bonds in the synthesis of organic compounds. In this reaction, an enone is attacked by a nucleophile in a conjugated manner across a carbon-carbon double bond. The present work reported the Michael reaction of indole with α,β-unsaturated ketones via alkylation to yield 3-(3-oxoalkyl) indole or β-indolyl ketones. Naturally available orange juice has been demonstrated to be an efficient green catalyst for the Michael addition reaction of indoles with various cyclic and acyclic unsaturated ketones. The products were characterised by 1H NMR spectroscopy and compared with literature. This one-step, simple process has afforded the 3-indolyl carbonyl compounds in short reaction times and excellent yields at room temperature. The present method developed an inexpensive synthetic process to prepare substituted indoles in a simple and eco-friendly way.

Photocatalyzed One‐Pot Selective Synthesis of γ‐(per)fluoroalkenylated α,β‐Unsaturated Carbonyl Compounds

AbstractWe report herein a general one‐pot perfluoroalkylation/dehydrohalogenation protocol for the selective perfluoroalkenylation of silyl dienol ethers in their γ position. Importantly, this methodology is applicable to the synthesis of a wide range of γ‐perfluoroalkenylated enals, enones and α,β‐unsaturated amides. Various perfluoroalkenyl moieties could be efficiently introduced, with an important impact on the E/Z diatereoselectivity of the newly formed fluorinated double bond.

Antimony Redox Catalysis: Hydroboration of Disulfides through Unique Sb(I)/Sb(III) Redox Cycling.

The stibinidene ArSbI (Ar = [2,6-(tBuN═CH)2-C6H3], 1) reacts with S2Tol2 (Tol = p-tolyl) to form ArSbIII(STol)2 (2), which upon treatment with pinacolborane, regenerates 1. These processes unveil an unprecedented antimony redox catalysis involving Sb(I)/Sb(III) cycling for the hydroboration of organic disulfides. Elementary reaction studies and density functional theory calculations support that the catalysis mimics transition metal processes, proceeding through oxidative addition, ligand metathesis, and reductive elimination. The thiophenols and sulfidoborates generated from the hydroboration of disulfides react in situ with α,β-unsaturated carbonyl compounds with the assistance of 1 as a base catalyst. These tandem reactions establish a one-pot synthetic method for β-sulfido carbonyl compounds, in which a stibinidene functions as a redox catalyst and a base catalyst successively, illustrating the versatility and efficiency of antimony catalysis in organic synthesis.

Functionalized olive wood shell stone as a new revalorized agri-food waste active in organocatalysis

Olive wood shell stone has been used as an effective matrix for silanization and further anchoring of an organic probe such as 3-(5-chloro-anthraquinonylamino)propanoic acid (1). Covalent fixation of the anthraquinoid molecule was achieved by a “grafting to” silanization process with 3-aminopropyltrimethoxysilane (APTMS) followed by an amidation procedure. Ligand 1 was routinely characterized by multinuclear magnetic resonance (1H, 13C and 15N) and X-ray diffraction crystallography, while the new agri-food revalorized organocatalyst material was characterized by a number of analytical techniques such as granulometry, elemental analysis, thermogravimetry, differential scanning calorimetry, X-ray photoelectron spectroscopy, FTIR (ATR and DRIFT), moisture content, Karl-Fisher, ζ-potential and optical and fluorescence microscopy. The new revalorized material was assayed in the heterogeneous organocatalytic cyanosilylation of carbonyls compounds under very mild conditions with excellent yields and high recyclability under both presence and absence of solvent. Kinetic studies were also performed in order to understand the water uptake implications of this new organocatalyst.

Intermolecular α-Functionalization of Benzylamides with N-Nucleophiles via Oxidative Umpolung: Synthesis of Tetrasubstituted 3,3'-Oxindoles.

A hypervalent iodine-mediated intermolecular α-umpolung reaction between α-aryl- or alkyl-substituted amides and benzotriazoles or purine derivatives as N-centered nucleophiles has been established. The reaction involves sequential intra/intermolecular oxidative C-N couplings in a controlled manner, affording tetrasubstituted 3,3'-oxindoles in moderate to good yields. This approach efficiently addresses the challenges in constructing tetrasubstituted carbon centers via α-umpolung functionalizations of carbonyl compounds and serves as a new strategy for synthesizing biologically important 3,3'-disubstituted oxindoles.

Energetics of the OH radical H-abstraction reactions from simple aldehydes and their geminal diol forms.

Carbonyl compounds, especially aldehydes, emitted to the atmosphere, may suffer hydration in aerosols or water droplets in clouds. At the same time, they can react with hydroxyl radicals which may add or abstract hydrogen atoms from these species. The interplay between hydration and hydrogen abstraction is studied using density functional and quantum composite theoretical methods, both in the gas phase and in simulated bulk water. The H-abstraction from the aldehydic and geminal diol forms of formaldehyde, acetaldehyde, glycolaldehyde, glyoxal, methylglyoxal, and acrolein is studied to determine whether the substituent has any noticeable effect in the preference for the abstraction of one form or another. It is found that abstraction of the H-atom adjacent to the carbonyl group gives a more stable radical than same abstraction from the geminal diol in the case of formaldehyde, acetaldehyde, and glycolaldehyde. The presence of a delocalizing group in the Cα (a carbonyl group in glyoxal and methylglyoxal, and a vinyl group in acrolein), reverts this trend, and now the abstraction of the H-atom from the geminal diol gives more stable radicals. A further study was conducted abstracting hydrogen atoms from the other different positions in the species considered, both in the aldehydic and geminal diol forms. Only in the case of glycolaldehyde, the radical formed by H-abstraction from the -CH2OH group is more stable than any of the other radical species. Abstraction of the hydrogen atom in one of the hydroxyl groups in the geminal diol is equivalent to the addition of the •OH radical to the aldehyde. It leads, in some cases, to decomposition into a smaller radical and a neutral molecule. In these cases, some interesting theoretical differences are observed between the results in gas phase and (simulated) bulk solvent, as well as with respect to the method of calculation chosen. DFT (M06-2X, B2PLYP, PW6B95), CCSD(T), and composite (CBS-QB3, jun-ChS, SCVECV-f12) methods using Dunning basis sets and extrapolation to the CBS limit were used to study the energetics of closed shell aldehydes in their keto and geminal-diol forms, as well as the radical derived from them by hydrogen abstraction. Both gas phase and simulated bulk solvent calculations were performed, in the last case using the Polarizable Continuum Model.

Catalytic Stability of S-1-(4-Hydroxyphenyl)-Ethanol Dehydrogenase from Aromatoleum aromaticum.

Derived from the denitrifying bacterium Aromatoleum aromaticum EbN1 (Azoarcus sp.), the enzyme S-1-(4-hydroxyphenyl)-ethanol dehydrogenase (S-HPED) belongs to the short-chain dehydrogenase/reductase family. Using research techniques like UV-Vis spectroscopy, dynamic light scattering, thermal-shift assay and HPLC, we investigated the catalytic and structural stability of S-HPED over a wide temperature range and within the pH range of 5.5 to 9.0 under storage and reaction conditions. The relationship between aggregation and inactivation of the enzyme in various pH environments was also examined and interpreted. At pH 9.0, where the enzyme exhibited no aggregation, we characterized thermally induced enzyme inactivation. Through isothermal and multitemperature analysis of inactivation data, we identified and confirmed the first-order inactivation mechanism under these pH conditions and determined the kinetic parameters of the inactivation process. Additionally, we report the positive impact of glucose as an enzyme stabilizer, which slows down the dynamics of S-HPED inactivation over a wide range of pH and temperature and limits enzyme aggregation. Besides characterizing the stability of S-HPED, the enzyme's catalytic activity and high stereospecificity for 10 prochiral carbonyl compounds were positively verified, thus expanding the spectrum of substrates reduced by S-HPED. Our research contributes to advancing knowledge about the biocatalytic potential of this catalyst.

Gold catalysis in quinoline synthesis.

Quinolines are biologically and pharmaceutically important N-heterocyclic aromatic compounds, which have broad applications in medicinal chemistry. Thus, their efficient synthesis has attracted extensive attention, and a broad range of synthetic strategies have been established. Of note, gold-catalyzed methodologies for the synthesis of quinolines have greatly advanced this field. Various gold-catalyzed intermolecular annulation reactions, such as annulations of aniline derivatives with carbonyl compounds or alkynes, annulations of anthranils with alkynes, and annulations based on A3-coupling reactions, as well as intramolecular cyclization reactions of azide-tethered alkynes, 1,2-diphenylethynes, and 2-ethynyl N-aryl indoles, have been developed. This review provides an overview of this exciting research area. Typical achievements in reaction methodologies and plausible reaction mechanisms are summarized.