Alcohol Research Articles

An SN1-Approach to Cross-Coupling: Deoxygenative Arylation Facilitated by the β-Silicon Effect.

We report a dual metal-catalyzed method for the cross-coupling of unprotected alcohols by exploiting the β-Si effect. This deoxygenative Suzuki-Miyaura reaction tolerates a range of primary, secondary, and tertiary alcohol substrates along with diverse functional groups and heterocycles. Mechanistic experiments including KIE, VTNA, and Eyring analyses suggest the existence of a carbocation intermediate on the reaction pathway, consistent with a rare SN1 pathway for the activation of an electrophile in cross-coupling reactions. A novel bis-imidazolium N-heterocyclic carbene (NHC) ligand was found to be optimal for reactivity, and nickel(0)-, nickel(I)- and nickel(II)- complexes of this ligand were isolated and characterized. In contrast to more well-established shorter chain ligands, these long-chain NHCs are found to have characteristically large bite angles, which may be critical for enabling the deoxygenative arylation of aliphatic alcohols.

Cover Image

The cover image is based on the Research Article Improving aromatic higher alcohol acetates in wines by co‐fermentation of Pichia kluyveri and Saccharomyces cerevisiae: growth interaction and amino acid competition by Yueqi Li et al., https://doi.org/10.1002/jsfa.13519.image

ADH‐Catalyzed Biooxidation of (Hetero)aromatic sec‐Alcohols to Ketones Employing Vinyl Acetate as Acetaldehyde Surrogate

AbstractThe oxidation of sec‐alcohols is a common reaction in organic chemistry. We report a biocatalytic approach for oxidizing racemic (hetero)aromatic sec‐alcohols to the corresponding ketones. The reaction relies on employing freeze‐dried E. coli cells containing a recombinant variant of an alcohol dehydrogenase deduced from Lactobacillus kefir (E. coli/Lk‐ADH Prince) and vinyl acetate as an in situ acetaldehyde surrogate as oxidant. Biooxidations of a set of 20 racemic (hetero)aromatic alcohols were carried out in the presence of a catalytic amount of NADP+ cofactor, the biocatalyst, and vinyl acetate in an aqueous medium to generate the corresponding ketones with up to >99 % conv. Preparative scale (1.0 mmol; 100 mM in 10 mL) reactions led to obtaining ketones in the 56–83 % isolated yield range.

Half-Sandwich Iridium Complexes: A Recyclable and Stable Catalyst for Dehydrogenation of Alcohols to Carboxylic Acids.

A series of acylhydrazone-based N,N-chelate half-sandwich iridium complexes have been synthesized through a facile route in good yields. The dehydrogenation of a series of aromatic and aliphatic primary alcohols to corresponding carboxylic acids has been accomplished catalyzed by the prepared air stable iridium complexes under mild reaction conditions. Carboxylic acids were obtained in high yields under open flask condition with broad substrates and good tolerance to sensitive functional groups. Such a half-sandwich iridium catalyst system exhibited high catalytic activity and stability, and a high TOF of 316.7 h-1 could be achieved with a catalyst loading as low as 0.05 mol %. Furthermore, the sustainable catalyst could be reused at least five times without obviously losing its activity, highlighting its potential application in industry. Molecular structure of iridium complex 1 was confirmed by single-crystal X-ray analysis.

Validating new coding algorithms to improve identification of alcohol-associated and nonalcohol-associated cirrhosis hospitalizations in administrative databases.

Alcohol (AC) and nonalcohol-associated cirrhosis (NAC) epidemiology studies are limited by available case definitions. We compared the diagnostic accuracy of previous and newly developed case definitions to identify AC and NAC hospitalizations. We randomly selected 700 hospitalizations from the 2008 to 2022 Canadian Discharge Abstract Database with alcohol-associated and cirrhosis-related International Classification of Diseases 10th revision codes. We compared standard approaches for AC (ie, AC code alone and alcohol use disorder and nonspecific cirrhosis codes together) and NAC (ie, NAC codes alone) case identification to newly developed approaches that combine standard approaches with new code combinations. Using electronic medical record review as the reference standard, we calculated case definition positive and negative predictive values, sensitivity, specificity, and AUROC. Electronic medical records were available for 671 admissions; 252 had confirmed AC and 195 NAC. Compared to previous AC definitions, the newly developed algorithm selecting for the AC code, alcohol-associated hepatic failure code, or alcohol use disorder code with a decompensated cirrhosis-related condition or NAC code provided the best overall positive predictive value (91%, 95% CI: 87-95), negative predictive value (89%, CI: 86-92), sensitivity (81%, CI: 76-86), specificity (96%, CI: 93-97), and AUROC (0.88, CI: 0.85-0.91). Comparing all evaluated NAC definitions, high sensitivity (92%, CI: 87-95), specificity (82%, CI: 79-86), negative predictive value (96%, CI: 94-98), AUROC (0.87, CI: 0.84-0.90), but relatively low positive predictive value (68%, CI: 62-74) were obtained by excluding alcohol use disorder codes and using either a NAC code in any diagnostic position or a primary diagnostic code for HCC, unspecified/chronic hepatic failure, esophageal varices without bleeding, or hepatorenal syndrome. New case definitions show enhanced accuracy for identifying hospitalizations for AC and NAC compared to previously used approaches.

Development of a γ-Al2O3-Based Heterogeneous Fenton-like Catalyst and Its Application in the Advanced Treatment of Maotai-Flavored Baijiu Wastewater

Heterogeneous Fenton technology was employed for the advanced treatment of Maotai-flavored Baijiu wastewater. Novel catalysts were prepared by loading different active ingredients (Mn, Fe, and Cu) on γ-Al2O3 using an impregnation method. The effects of active ingredient, reaction time, initial pH, H2O2 dosage, catalyst dosage, and other factors on the reaction were examined. The properties of the new catalysts were analyzed using BET analysis, XPS, and SEM. Moreover, the mechanisms of Fenton-like oxidation and its reaction kinetics were explored through experiments and analyses including GC–MS and intermediate active species scavenging by tertiary butyl alcohol (TBA) and/or para-benzoquinone. The results revealed that the most effective removal of organic matter was achieved with a Mn-Fe/Al (2:1 wt%) catalyst dosage of 30 g/100 g water, pH of 5.0, H2O2 dosage of 0.3 g/L, and reaction time of 60 min; the effluent COD value was 12 ± 1 mg/L, and the degradation rate was 65.7 ± 3%, approximately 14% higher than that of the conventional Fenton catalyst under similar conditions; moreover, the catalytic efficacy remained high after seven cycles. Kinetic analysis indicated that the heterogeneous Fenton oxidation reaction followed a third-order kinetics model, with R2 = 0.9923 and K = 0.0006 min−1.

Solvent-assisted salt-free reactive dyeing of cotton fabric

The objective of this study was to establish a solvent-assisted salt-free dyeing method for cotton fabric utilizing commercially available reactive dyes. In this study, the feasibility of substituting water as the dyeing medium with environmentally friendly solvents, specifically ethanol (EtOH), isopropyl alcohol (IPA), and propanol (PrOH), was investigated. Eight commercial reactive dyes, each possessing distinct chemical structures, were examined with various dyeing characteristics including exhaustion, fixation, and fastness properties, in the presence of various alcohols. However, solvent-assisted dyeing exhibited comparable or enhanced color strength (K/S) values, exhaustion, and fixation rates compared to conventional aqueous dyeing. For instance, the RR35 dye demonstrated a substantial increase in K/S values with PrOH, EtOH, and IPA, ranging from 115 to 369% improvement. The substitution of alcohol for water did not affect the wash, rub, and light-color fastness properties, as these properties remained consistently excellent. Solvent-assisted salt-free dyeing of cotton fabrics offers a promising solution to address the environmental impacts of traditional water-based dyeing methods by eliminating the requirement for water and salt. Overall, this study presents a solvent-assisted salt-free dyeing technique and contributes to the field by offering detailed insights into its mechanisms and performance. Our research has the potential to reduce water consumption, eliminate salt usage, and mitigate environmental pollution.

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.

Catalytic Enantioselective Hydroxylation of Tertiary Propargylic C(sp3)-H Bonds in Acyclic Systems: a Kinetic Resolution Study.

Direct site-selective and enantioselective oxyfunctionalization of C(sp3)-H bonds to form alcohols with a general scope, with predictable selectivities, and in preparatively useful yields represents a paradigm shift in the standard logic of synthetic organic chemistry. However, the knowledge of either enzymatic or nonenzymatic asymmetric hydroxylation of tertiary C-H bonds for enantioenriched tertiary alcohol synthesis is sorely lacking. Here, we report a practical manganese-catalyzed enantio-differentiating hydroxylation of tertiary propargylic C-H bonds in acyclic systems, producing a wide range of structurally diverse enantioenriched tertiary propargyl alcohols in high efficiency with extremely efficient chemo- and enantio-discrimination. Other features include the use of C-H substrates as the limiting reagent, noteworthy functional group compatibility, great synthetic utilities, and scalability. The findings serve as a blueprint for the development of metal-catalyzed asymmetric oxidation of challenging substrates.

Water Microdroplets Surrounded by Alcohol Vapor Cause Spontaneous Oxidation of Alcohols to Organic Peroxides.

Using real-time mass spectrometric (MS) monitoring, we demonstrate one-step, catalyst-free spontaneous oxidation of various alcohols (ROH) to key reactive intermediates for the formation of ROO- compounds on the surface of water microdroplets surrounded by alcohol vapor, carried out under ambient conditions. These organic peroxides (POs) can act as important secondary organic aerosols (SOA). We used hydrogen-deuterium exchange by spraying D2O instead of H2O to learn about the reaction mechanism, and the results demonstrate the crucial role of the water-air interface in microdroplet chemistry. We find that the formation of POs relies on electron transfer occurring at the microdroplet interface, which generates hydrogen atoms and hydroxyl radicals that lead to a cascade of radical reactions. This electron transfer is believed to be driven by two factors: (1) the emergence of a strong electrostatic potential on the microdroplet's surface; and (2) the partial solvation of ions at the interface. Mass spectra reveal that the formation of POs is dependent on the alcohol structure, with tertiary alcohols showing a higher tendency to form organic peroxides than secondary alcohols, which in turn are more reactive than primary alcohols.

Development of an Easy-To-Handle Redox Active Group for Alcohols: Catalytic Transformation of Tertiary Alcohols to Nitriles.

The generation of radical intermediates via SET-mediated deoxygenation of activated alcohol derivatives is desirable, as alcohols can be utilized in various radical-mediated reactions. Herein, we introduce α-N-phthalimido-oxy isobutyrate (NPIB) as a novel activating group for alcohols. Essentially, it is a more chemically robust alternative to Overman's N-phthalimidoyl oxalate group. The utility of the NPIB group is showcased in the conversion of tertiary alcohols to nitriles under Ir/Cu dual catalysts and in the presence of TMSCN upon blue LED irradiation. With our newly developed NPIB handle, the reactivities of N-hydroxyphthalimide esters derived from carboxylic acids would be achievable with naturally and commercially more abundant alcohol substrates.

Photoredox- and Cobalt-Cocatalyzed Dehydrogenative Ring-Opening/Functionalization of Monodonor Cyclopropanes

AbstractCatalytic ring-opening/functionalization of unactive cyclopropanes has proven to be a significant but challenging task in organic synthesis. Herein, we disclose the photoredox and cobalt cocatalyzed ring-opening/acceptorless dehydrogenative functionalization of monodonor cyclopropanes, which provides a promising platform to achieve a sustainable and atom-economic approach to assemble allylic N-acyl-acetal derivatives. The reaction features mild conditions, broad substrate scopes, and excellent functional group compatibilities. The optimized conditions accommodate various cycloalkylamides and primary, secondary, and tertiary alcohols, with applications in late-stage functionalization of pharmaceutically relevant compounds, stimulating the further utility in medicinal chemistry. Selective nucleophilic substitutions and further transformations of desired products with various carbon nucleophiles were succeed in a one-pot fashion, thus offering diverse acyclic or cyclic derivatives.1 Introduction2 Cooperative Photoredox and Cobalt-Catalyzed Dehydrogenative Functionalization of Allylic N-Acyl-acetal Derivatives3 Mechanistic Study4 Preliminary Studies of Asymmetric Transformation5 Conclusion and Perspectives

Advances in synthesis of 2-phenylethanol

2-phenylethanol (2-PE), an aromatic alcohol with a rose fragrance, is the second most widely used flavoring substance in the world. It is widely used in the cosmetic, food, and pharmaceutical industries. This paper introduces the chemical synthesis methods of 2-PE and the synthetic pathways in plants and microorganisms, summarizes the strategies to improve the microbial synthesis of 2-PE, reviews the research progress in de novo synthesis of 2-PE in microorganisms, and makes an outlook on the research prospects, aiming to provide a theoretical basis for the industrial production of 2-PE.

Metal-free, light assisted integrated CO2 reduction coupled with selective oxidation of alcohols under visible light irradiation

An integrated CO2 photoreduction to CO by photo-induced electrons coupled with selective oxidation of aromatic alcohols to carbonyl compounds by photo-generated holes using metal-free anthraquinone (AQ) as an organo-photocatalyst under visible illumination is described. The maximum conversion of benzyl alcohol to benzaldehyde was 65.6% with a selectivity of 98 %, accompanied with the CO yield in gaseous phase 8.67 μmol h−1 g.−1 DFT calculations indicated that initial binding of benzyl alcohol with AQ formed an intermediate IM1 that subsequently interacted with CO2 to give CO2 anion with a free energy change of 0.24 eV. Further, the reduction of CO2 accompanied with the oxidation of benzyl alcohol provided CO and benzaldehyde, respectively along with the release of a water molecule. This concerted metal-free photocatalytic system offers the efficient use of electron-hole pairs for organic synthesis coupled with the CO2 conversion in a cost-effective and sustainable manner.

Research on the design and application of efficient catalysts based on interfacial chemistry: Molecular catalysts in gas-liquid mixed systems

Major challenges existing in the photocatalytic gas-liquid mixing system model include the mass transfer limit at the gas-liquid interface and the depth of light penetration. For this purpose, amphiphilic molecular catalysts were prepared by monovacancy phosphomolybdate modified by propyltrimethoxysilane. It is also used as a photocatalyst in the model reaction (molecular oxygen oxidation of aromatic alcohol). The amphiphilic molecular catalyst in the reaction is similar to surfactant behavior, not only can adsorb in the gas-liquid interface, ensure the direct contact between oxygen, catalyst and reactants, improve the efficiency of mass transfer, and also reduce the surface tension of aromatic alcohol, gas-liquid-solid three-phase system into foam system. The formed foam system amplifies the interface area of the reaction, enhances the light penetration depth and significantly promotes the reaction rate. The insights gained from our study provide a new perspective on the design of photocatalysis in a gas-liquid hybrid system.

Elemental analysis and metabolic profiling of medicinally potent members of Zingiberaceae family using FT-IR and LIBS coupled with PLS-DA

The role of organic and inorganic elemental profiles in the growth, development, and secondary metabolite synthesis of plants is crucial, particularly concerning their medicinal value. However, comprehensive studies addressing both aspects are scarce. Hence, the present manuscript aims to investigate the potential use of Fourier transform infrared spectroscopy (FT-IR) and laser-induced breakdown spectroscopy (LIBS) techniques to obtain the functional groups and organic and inorganic elemental profiles of significant medicinal plants belonging to the Zingiberaceae family collected from two different geographic regions in India. The FT-IR analysis of the methanolic extracts shows the presence of aliphatic and aromatic alcohols, esters, ethers, carboxyl compounds, and their derivatives. In LIBS analysis, the spectral characteristics of atomic and molecular species present in the samples were observed, encompassing both organic and inorganic elements. The presence of heavy metals and trace elements have also been observed in the LIBS spectra of the samples. Furthermore, partial least squares discriminant analysis (PLS-DA) has been used to obtain classification pattern of the samples based on their spectral fingerprints. This study not only helps in reflecting the significance of micronutrients in aiding secondary metabolism thus enhancing the medicinal properties of plants, but also enables the identification of trace elements within plants. This facilitates the determination of the suitable usage and dosage of particular plant components, contributing to the research goal of establishing pharmacological and nutraceutical significance. This study is imperative as it fills a critical gap in research, although further work in this direction is warranted.

Brønsted Acid Catalyzed Dehydroxylative Cyanation of Benzylic Alcohols with Trimethylsilyl Cyanide Using 1,1,1,3,3,3‐Hexafluoro‐2‐propanol as a Solvent

AbstractA concise and direct Brønsted acid catalyzed cyanation of secondary and tertiary benzylic and allylic alcohols has been developed using trimethylsilyl cyanide (TMSCN) as a cyanide source and 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) as a solvent. The present transition‐metal‐free catalytic process is operationally simple to perform under “open‐flask” conditions and is applicable to the preparation of a number of α‐arylacetonitriles as well as late‐stage material transformations. The effectiveness of the present protocol was further demonstrated by the first enantioselective synthesis and determination of the absolute configuration of verimol F.

A green and pollution-free heterogeneous ruthenium catalyst anchoring on magnetic nanoparticles with FPBA and DTPA groups for oxidation of aromatic alcohols

Using ruthenium chloride as catalyst precursor, magnetic silicon spheres as support, 4-formylphenylboronic acid and ethylenediaminepentaacetic acid as functional ligands, a magnetic heterogeneous nano-ruthenium catalyst (Fe3O4@SiO2-FPBA-DTPA-Ru) was prepared for the first time. It was nano level with 20.17 emu/g saturation magnetic strength and thermal stability under 249.63 °C. Fe3O4@SiO2-FPBA-DTPA-Ru contained 0.38 mmol/g Ru and was successfully used to catalyze the oxidation reactions of 15 aromatic secondary alcohols. Results proved that Fe3O4@SiO2-FPBA-DTPA-Ru as catalyst had good catalytic activity for the oxidation of secondary aromatic alcohols with yields exceeding 90 % for 12 products and 95 % for 10 products. High TON and TOF values (6386 and 9158 h−1) in 1-phenylethanol oxidation were obtained. All the reactions of aromatic alcohols were carried out in a solvent-free system, so the prepared catalyst had the characteristics of green and pollution-free. It was’nt suitable for oxidation of aromatic primary alcohols. If there was steric hindrance around the hydroxyl group in substrate, the catalysis also may be limited. The Fe3O4@SiO2-FPBA-DTPA-Ru catalyst also exhibited the advantages of energy saving, satisfactory reusability and stability in 9 consecutive runs. It showed great potential for future large-scale industrial production.

Selectivity switch via tuning surface static electric field in photocatalytic alcohol conversion

Photocatalysis has shown great potential in organic reactions, while controlling the selectivity is a long-standing goal and challenge due to the involvement of various radical intermediates. In this study, we have realized selectivity control in the photocatalytic conversion of alcohols via engineering the surface static electric field of the CdS semiconductor. By leveraging the Au-CdS interaction to adjust lattice strain, which influences the intensity of the surface static electric field, we altered the pathways of alcohol conversion. The increased intensity of the surface static electric field changed the activation pathways of the C-H/O-H bond, leading to the selective formation of targeted C/O-based radical intermediates and altering the selectivity from aldehydes to dimers. A wide range of alcohols, such as aromatic alcohol and thiophenol alcohol, were selectively converted into aldehyde or dimer. This work provides an effective strategy for selectively controlling reaction pathways by generating a surface electric field.

Walnut shell oil-bath torrefaction coupled with fast pyrolysis: Effect of torrefaction heating modes

Lignocellulosic biomass, renewable with short growth cycle and diverse sources, can be substituted fossil fuel. However, low effective hydrogen-to-carbon ratio (H/Ceff) limits its applications. Torrefaction and co-pyrolysis with high H/Ceff feedstocks are promising technology. This paper investigated the effect of heating modes on oil-bath torrefaction of walnut shells, followed by fast co-pyrolysis. Six heating modes during oil-bath torrefaction were evaluated. Com1 (Microwave 67 %, Lightwave 33 %) yielded the lowest residual yield 84 wt%, while the highest gas production 495.47 mL/g which mainly composed of CO and CO2. Torrefied feedstock under Com1 had the highest H/Ceff. Decarboxylation and decarbonylation reactions dominated among oil-bath torrefaction. Com1 produced the most hydrocarbons and least oxygen-containing compounds. As microwave ratio decreased, the content of olefins, acids and phenols decreased, monocyclic aromatic hydrocarbons and alcohols was showed opposite tend. This study offers new ideas for microwave and lightwave torrefaction and promoting hydrocarbon production from lignocellulosic biomass.