Series Of Alcohols Research Articles

C‐C Coupling of Methylene Ketones with Alcohols Enabled by Fe‐Catalysis: Access to Substituted Pyrroles and Pharmaceuticals

Herein, we have reported a sustainable and chemo‐selective strategy for the synthesis of functionalized branched alcohols. Commercially available catalytic system does not need any special ligand and liberated water and hydrogen as side product. A series of alkyl primary alcohols (C4‐C10) including methanol were tolerated in good to high yield. Sequential transformations to substituted pyrroles, chromenes and synthesis of donepezil drug were obtained (>57 entries). Preliminary mechanistic investigations were performed to understand the catalytic pathways.

Palladium-Catalyzed Ortho Alkoxylation of Oxazoline Derivatives: An Avenue to Reach Meta-Substituted Electron-Rich Arenes Exploiting Oxazoline as a Removeable Directing Group.

An efficient and highly regioselective palladium-catalyzed oxazoline-directed alkoxylation is reported. The reaction proceeds under air and mild temperatures (60 °C). A series of alcohols can be used as alkoxylating agents and concomitantly act as reaction solvents, whereas primary and secondary alcohols are tolerated. Furthermore, fluorinated alcohols can be applied as well, introducing pharmaceutically relevant fluorine-containing groups. 1,3-Dialkoxylated products can be further subjected to hydrolysis transforming the oxazoline-directing group to a carboxylic acid, which can be removed by decarboxylation if desired. This approach demonstrates the capability to reverse the conventional site selectivity of electrophilic aromatic substitution reactions, since it allows the synthesis of arenes with two electron-donating groups in a 1,3-relationship.

Efficient synthesis of highly hydrophobic lignin nanoparticles and their application as nano fillers for multifunctional composite membranes

Controlling the hydrophobic behaviors of lignin nanoparticles (LNPs) is crucial and advantageous for their application as film Nano Fillers, yet it poses a significant challenge. Herein, we successfully developed a novel method for the preparation of LNPs with highly hydrophobic behaviors using ternary deep eutectic solution (DES)-H2O systems. The resulting LNPs exhibit a significantly reduced content of hydrophilic groups on their outer surface, leading to a zeta potential value of only −4.9 mV, and up to 140.0° of water contact angle (WCA). Afterwards, a “Dissolution-Restructuration” mechanism was proposed to explain the formation of the prepared LNPs. Firstly, DES demonstrates superior H-bonding capabilities, facilitating the complete disruption of inter- and intramolecular H-bonding in lignin, and resulting in the formation of a highly homogenized lignin network. Subsequently, the DES system undergoes compromise after adding water, triggering the reformation of both inter- and intramolecular H-bonding and π-π interactions. Consequently, lignin orderly self-assembles into LNPs with highly hydrophobic characteristics. Especially, using the as-prepared LNPs as Nano fillers, a series of LNPs-containing polyvinyl alcohol (PVA) films were successfully fabricated, exhibiting exceptional hydrophobic behaviors (with contact angles reaching up to 124.0°). Furthermore, the mechanical strength, UV-shielding capabilities, and biodegradability of the PVA films are significantly enhanced. This study introduces a sustainable and efficient approach for the synthesis of hydrophobic LNPs, thereby facilitating the broadening of applications for lignin-based functional composite film materials.

Chemo-enzymatic, regioselective synthesis of dihydropyrimidinone-fused β-amino alcohols and their anti-inflammatory and antioxidant activity evaluation

A highly regioselective and efficient method has been developed for synthesizing novel β-amino alcohols fused with dihydropyrimidin-2-one. This method utilizes the enzyme Novozyme-435 to catalyze the reaction between epoxides and various aliphatic amines in acetonitrile. Novozyme-435 outperformed other catalysts, including Porcine Pancreatic Lipase (PPL), Pseudomonas aeruginosa lipase (PAL), and Candida rugosa lipase (CRL). This process yielded two series of β-amino alcohols (compounds 8a-h and 9a-h), whose structures were confirmed through IR, NMR (1H, 13 C), and HRMS analyses. The anti-inflammatory and antioxidant properties of these compounds were evaluated, revealing mild to moderate inhibition of TNF-α-induced ICAM-1 expression in primary human endothelial cells, with compounds 9a and 9c showing approximately 60% inhibition. Antioxidant activity, assessed using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, indicated that compounds 9a, 9b, 9c, and 9 g had the superior activity than others. This study highlights the potential of these β-amino alcohols fused with dihydropyrimidin-2-one as anti-inflammatory and antioxidant agents.

Fully renewable oxygen barrier films of scCO2-processed thermoplastic starch/sugar alcohol blends

Abstract Excellent oxygen barrier films were prepared by blending very small loadings (<1 wt%) of dihydroxyacetone (DHA), erythritol (ET) or xylitol (XT) in thermoplastic starch (TPS), and/or processing with supercritical carbon dioxide (scCO2) assistance. The minimum oxygen transmission rates (OTR) and all free-volume-hole characteristic (FVH) values of each scCO2-processed TPS/sugar alcohol film series are somewhat smaller than those of corresponding TPS/sugar alcohol film series without scCO2-assistance, and decrease with the decrease in sugar alcohol’s molecular weight. The minimum OTR values acquired for scCO2-processed TPS/DHA and TPS/ET blown films are only 3.6 and 4.3 cm3/m2·day·atm, respectively, which meet the demand of high oxygen barrier films having OTR ≦5 cm3/m2·day·atm. The longitudinal or transversal tensile strengths acquired for each scCO2-processed TPS/sugar alcohol series films are ∼30 % to ∼40 % higher than those of the TPS blown films. Dynamic mechanical relaxations of each TPS/sugar alcohol or scCO2-processed TPS/sugar alcohol film series reveal that the sugar alcohols are compatible with TPS, as their sugar alcohol contents are ≤ the corresponding compatibility values. The decreased OTR and FVH values acquired for TPS/sugar alcohol or scCO2-processed TPS/sugar alcohol films are most likely due to them being scCO2-processed or incorporated with smaller molecular weight of sugar alcohols.

Influence of the alkyl chain-length on the luminescent properties of 6‑hydroxy-2-naphthoate moieties: Preparation, crystal structure and Hirshfeld surface analysis

To further explore the luminescent materials, a set of 6‑hydroxyl-naphthoate derivatives have been obtained through the esterification reaction of 6‑hydroxy-2-naphthoic acid with a series of organic alcohols (methanol, ethanol, n-propanol and n-butanol, respectively) in the presence of phenyl sulfonic acid. The title compounds were characterized by FT-IR, elemental analysis (EA), UV–vis spectra, NMR and single-crystal X-ray diffraction. Compounds 1–5 are 6‑hydroxy-2-naphthoic acid, methyl 6‑hydroxy-2-naphthoate, ethyl 6‑hydroxy-2-naphthooate, n-propyl 6‑hydroxy-2-naphthoate and n‑butyl 6‑hydroxy-2-naphthoate, respectively. Compounds 1–5 crystallizes in the space group P21/c, Pna21, P21/n, P21/c and P-1, respectively. The C/OH···O hydrogen bonds can be observed. The luminescent emission maxima of compounds 1–5 can be found at 386, 393, 405, 407 and 420 nm in the solid state, respectively, indicating that the photoluminescent peaks occur the bathochromic-shift with the growth of the alkyl chain-lengths. Additionally, there exists the same order for the quantum yields. Meanwhile, the Hirshfeld surface analysis proves that the H···H interactions can be responsible for the emission maxima of these target compounds. The trend of the melting point decreases with the reduction of O···H interactions, and with the increment of the alkyl chain-lengths. The repulsion energy of the target compounds also shows the same tendency, which can be confirmed by the energy framework analysis.

Multigram two-step synthesis of difluoromethyl ethers from aliphatic alcohols and glycols

A convenient method for synthesis of alkyl(difluoromethyl)ethers, including subsequent stages of chlorination and fluorination of the O-formyl derivatives was investigated on series of aliphatic alcohols and glycols. Primary and secondary alcohols are converted to the corresponding O-difluoromethyl derivatives in high yield, polydifluoromethyl derivatives of 1,3-propyleneglycol, diethyleneglycole and pentaerythritol can only be successfully obtained with this procedure.

Half‐sandwich iridium complexes: Synthesis and catalytic activity in dehydrogenation of alcohols to carboxylic acids

A series of N,N‐chelate half‐sandwich iridium complexes were synthesized by a simple method with good yields. The dehydrogenation of a series of aromatic and aliphatic primary alcohols to corresponding carboxylic acids has been successfully achieved 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 showed desirable stability and catalytic activity, and the achievement of a high TOF of 372.0 h−1 could be observed with an extremely low catalyst loading of only 0.05 mol%. Furthermore, the sustainable catalyst could be reused for a minimum of five cycles without obviously losing its activity, highlighting its potential application in industry. Structure of N,N‐chelate iridium complexes 1 and 3 were determined by single‐crystal X‐ray analysis.

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.

The effect of an annual temporary abstinence campaign on population-level alcohol consumption in Thailand: a time-series analysis of 23 years

RationaleA small number of earlier studies have suggested an effect of temporary abstinence campaigns on alcohol consumption. However, all were based on self-reported consumption estimates.ObjectivesUsing a time series of 23-year...

Asymmetric carbohydroxylation of alkenes via sequential photocatalytic oxo-alkylation and enzymatic reduction

Asymmetric carbohydroxylation of alkenes offers an efficient approach to access chiral alcohols, a class of versatile building blocks in pharmaceutical and agrochemical industries, from abundant simple alkenes. Herein we reported a sequential photo-biocatalysis protocol for the asymmetric carbohydroxylation of alkenes, involving a stepwise photocatalytic decarboxylative radical addition/Kornblum oxidation and enzymatic reduction. A series of chiral alcohols with bulky structures were synthesized in up to 75 % isolated yields and 99 % ee from N-hydroxyphthalimide esters and aryl alkenes.

5-Trifluoromethoxy-substituted Nicotinic Acid, Nicotinamide and Related Compounds

A practical and convenient method for synthesizing nicotinic acid and nicotinamide with the trifluoromethoxy group in position 5 of the ring has been developed. A series of related compounds, for example, nicotinic aldehyde and nicotinic alcohol, have been synthesized. It has been shown that 3-bromo-5-trifluoromethoxypyridine is a convenient and efficient synthon for palladium-catalyzed coupling reactions. The trifluoromethoxy group has been found to be remarkably stable against hydroiodic acid in contrast to the methoxy group.

Whole-cell Lipase Catalytic Synthesis of Short-chain Fragrance Esters using Aspergillus flavus

Background: Fragrances are the collection of unlike functional assemblies, most likely alcohols, esters, aldehydes, ketones, and acids in organic products/hydrocarbons. Short-chain aliphatic fragrance esters have immense applications as flavors in the food, pharmaceutical and cosmetic industries and also have remarkable commercial significance in cosmetics and personal care products like perfumes, face creams, shampoos, soaps, lotions, jams, jellies, etc. Objective: This study aimed to synthesize short-chain fragrance esters using a whole-cell lipase catalyst from Aspergillus flavus (RBD-01). Method: The present study emphasizes the synthesis of artificial flavoring compounds by using a wholecell biocatalytic process, which can have wide significance. Herein, the preparation of ethyl alkanoates (ethyl propanoate to ethyl decanoate) was performed to investigate the flavors and fragrance excellence. The biomass from Aspergillus flavus (RBD-01) was used as a catalyst to facilitate the remarkable esterification activities towards the synthesis of important aroma esters with the help of a series of short-chain acids and alcohols. Result: The ethyl hexanoate (4) among all synthesized alkanoates was found to have a fruity fragrance with a good conversion rate. Further synthesized alkyl hexanoates (4A-4I) were found to have good fruity/pineapple/berry flavors and significant aroma quality. Conclusion: These results implied that whole-cell lipase of Aspergillus flavus (RBD-01) is a promising biocatalyst in the production of flavor aroma esters and can boost production in the food/cosmetic manufacturing industries.

Emodin Alcohols: Design, Synthesis, Biological Evaluation and Multitargeting Studies with DNA, RNA, and HSA.

A series of novel emodin alcohols were designed and prepared in an effort to overcome the increasing microorganism resistance. Novel emodin alcohols were prepared from commercial emodin and different nitrogen-containing heterocycles via different synthetic strategies, such as O-alkylation and N-alkylation. The antimicrobial activity of synthesized emodin compounds was evaluated in vitro by a two-fold serial dilution technique. The interaction of emodin compound 3d with biomolecule was researched using UV-vis spectroscopic method and fluorescence spectroscopy. Emodin compound 3d containing 2-methyl-5-nitro imidazole ring showed relatively good antimicrobial activity. Notably, it exhibited equivalent activity against S. aureus in comparison to the reference drug norfloxacin (MIC = 4 μg/mL). The combination of strong active compound 3d with reference drugs showed better antimicrobial activity with less dosage and a broader antimicrobial spectrum than their separate use. Further research displayed that emodin compound 3d could intercalate into S. aureus DNA to form the 3d-DNA complex, which might correlate with the inhibitory activity. The hydrogen bonds were found between S. aureus DNA gyrase and strong active compound 3d during the docking research, which were in accordance with the spectral experiment results. The interaction with yeast RNA of compound 3d could also form a complex via hydrogen bonds. The hydrogen bonds were found to play a major role in the transportation of emodin compound 3d by human serum albumin (HSA), as confirmed by molecular simulation. This work provides a promising starting point to optimize the structures of emodin derivatives as potent antimicrobial agents.

Comparison of the effect of Sunset yellow on the stomach and small intestine of developmental period of mice

Sunset Yellow (SY), a synthetic food dye, is widely used in the food industry worldwide. The acceptable daily dosage for SY is 2.5 mg/kg/bw in humans. If SY is consumed in overdosage, it may cause histopathological effects in several organs. Studies in the literature about the effects of SY on growth and development in mammals are contradictory, and there are not enough of them. The investigation aims to determine SY's effects on the stomach and small intestine in different age groups of mice using histological methods. Control and treatment groups were created via mice aged 4, 8, and 10 weeks (n = 6). SY was administered by gavage at a level of 30 mg/kg/bw for 28 days to treatment groups. On the last day of the study, the mice were weighed and sacrificed by cervical dislocation. Stomach and small intestine tissues were removed from mice and transferred to 10 % formaldehyde. After passing through alcohol and xylene series and staining with Hematoxylin-Eosin, the tissues were evaluated under light and electron microscopy. The mean body weight (p = 0.01), mean stomach weight (p = 0.03), and mean small intestine weight were increased (p = 0.02) in treatment groups. In these groups, ruptures, fractures, and hemorrhage were detected in the small intestine tissue. In the stomach tissue, necrotic areas and hemorrhage were detected among the epithelial cells. The degenerations were more advanced in the weaning group. SY may be more harmful during weaning and puberty, but additional long-term studies are needed on the subject.

Dispersive surface free energy of adsorbents modified by supramolecular structures of heterocyclic compounds

In the present work, the dispersive surface free energy was calculated by Dorris-Gray method for 30 samples of adsorbents modified with chiral supramolecular structures of uracil, 6-methyluracil, 5-hydroxy-6-methyluracil, 5-fluorouracil, thymine, melamine, cyanuric and barbirutic acids, and perylene-3,4,9,10-tetracarboxylic dianhydride. It was shown that the homologous series of n-alkanes is better suited for measuring dispersive surface free energy than the homologous series of alcohols. It was established that the classical Dorris-Gray method does not allow obtaining well interpretable data for the objects studied. This is due to a noticeable effect that inductive interactions of a polar surface as an inductor with nonpolar alkane molecules have on the calculated values. We suggested to modify the Dorris-Gray method, making it possible to obtain data on the dispersive component of the free energy of adsorption. It was shown that the changes in dispersive surface free energy as a result of the modification correlate well with data on the structure and properties of supramolecular ensembles of the modifiers used. The results obtained can be used to predict the enantioselectivity of chiral adsorbents.

Determination of the effects of sunset yellow on mouse liver and pancreas using histological methods.

Sunset Yellow (SY) is an azo synthetic food dye. Although the amount of SY consumed varies in different periods of life, it increases especially in children and adolescents. It may cause pathologic effects in organs at early ages. The aim of this study was to determine the effects of SY on the liver and pancreas of mice of different age groups using histological methods. The study included Swiss albino mice that were divided into three treatment groups and three control groups based on age (4, 8, and 10weeks old), with six mice in each group (n=6/group). SY was administered at 30mg/kg/bw/week orally for 28days to treatment groups. The liver and pancreas tissues were kept in 10% formaldehyde, then passed through alcohol and xylene series and stained with Hematoxylin-Eosin. They were evaluated using light and electron microscopy. In SY groups, the mean body weight (p: 0.026) and the mean liver weight (p: 0.013) of the mice increased, and their mean pancreas weight decreased (p: 0.045).The numbers of degenerative cells in the liver tissues of the mice in the SY groups were high. Severe dilation in the sinusoids and haemorrhages focused around the Vena Cava were detected. In the pancreatic tissues of the SY groups, increases in fibroblasts and lymphocytic infiltration were observed. Pathologies interpreted as chronic pancreatitis were more intense in the weaning group (4weeks old). SY may be more harmful at an early age, and it may be beneficial to limit its use during this period.

Modeling order–disorder boundaries of colloidal dispersions in organic solvents using interaction force measurements

HypothesisThe formation of soft colloidal crystals, which are nonclose-packed ordered arrays of colloidal particles suspended in a solvent, is dictated by a single physical factor that yields a fixed threshold at order–disorder boundaries for different experimental conditions such as ion concentration, solvent type, and particle size. Identifying the determinant factor and its threshold value should enable the prediction of the critical concentrations of colloidal particles to form soft colloidal crystals. ExperimentsSoft colloidal crystals were fabricated using a series of monohydric alcohols as dispersion media and reflectance spectra were measured to locate order–disorder boundaries. The interaction forces acting between particles were also measured by employing atomic force microscopy. FindingsThe interparticle forces at the order–disorder boundaries exhibited a universal threshold that was independent of the solvent types including alcohols and water. Therefore, the determinant factor for the formation of soft colloidal crystals was determined to be the force acting between the particles. Furthermore, a priori calculation of this critical force and consequently the critical particle concentration in colloidal systems was demonstrated by referring to the pressure at the liquid-to-solid transition in a hard sphere system (Alder transition).

Electrochemical Azo-free Mitsunobu-type Reaction.

The classic chemical Mitsunobu reaction suffers from the need of excess alcohol activation reagents and the generation of significant by-products. Efforts to overcome these limitations have resulted in numerous creative solutions, but the substrate scope of these catalytic processes remains limited. Here we report an electrochemical Mitsunobu-type reaction, which features azo-free alcohol activation and broad substrate scope. This user-friendly technology allows a vast collection of heterocycles as the nucleophile, which can couple with a series of chiral cyclic and acyclic alcohols in moderate to high yields and excellent ee's. This practical reaction is scalable, chemoselective, uses simple Electrasyn setup with inexpensive electrodes and requires no precaution to exclude air and moisture. The synthetic utility is further demonstrated on the structural modification of diverse bioactive natural products and pharmaceutical derivatives and its straightforward application in a multiple-step synthesis of a drug candidate.

Electrochemical Azo‐free Mitsunobu‐type Reaction

AbstractThe classic chemical Mitsunobu reaction suffers from the need of excess alcohol activation reagents and the generation of significant by‐products. Efforts to overcome these limitations have resulted in numerous creative solutions, but the substrate scope of these catalytic processes remains limited. Here we report an electrochemical Mitsunobu‐type reaction, which features azo‐free alcohol activation and broad substrate scope. This user‐friendly technology allows a vast collection of heterocycles as the nucleophile, which can couple with a series of chiral cyclic and acyclic alcohols in moderate to high yields and excellent ee's. This practical reaction is scalable, chemoselective, uses simple Electrasyn setup with inexpensive electrodes and requires no precaution to exclude air and moisture. The synthetic utility is further demonstrated on the structural modification of diverse bioactive natural products and pharmaceutical derivatives and its straightforward application in a multiple‐step synthesis of a drug candidate.