Synthesis Of Alcohols Research Articles

Palladium-catalyzed epoxidation of olefins using electrophiles as oxidizing agents

The development of palladium-catalysed olefin epoxidation reactions using electrophilic reagents as oxidants: modular synthesis of oxazolines. The efficient synthesis of esters, alcohols and halogen-containing products was achieved.

Visible-light-induced catalyst-free reductive coupling of aldehydes, ketones and imines with cyanopyridines.

This article introduces a reductive coupling driven by visible-light, facilitating the synthesis of pyridine-substituted alcohols and amines through the reaction of aldehydes, ketones and imines with cyanopyridines. Hantzsch esters serve as reductants in this process, eliminating the need for transition-metals or photosensitizers. The method demonstrates extensive compatibility and finds utility in the late-stage functionalization of both natural and pharmaceutical products, offering a sustainable pathway for the diversification of chemical compounds.

Synthesis of β-amino alcohols by ring opening of epoxides with amines catalyzed by sulfated tin oxide under mild and solvent-free conditions

One significant and elegant method for creating β-amino alcohols, which are useful intermediates for the synthesis of many different natural and synthetic pharmaceutical compounds, is to open the rings of epoxides with amines. When sulfated tin oxide catalyst (2 mol%) is present, epoxides can open their rings and react with amines to produce corresponding β-amino alcohols in good to high yields under mild circumstances. Under clean circumstances and in a short amount of time, the reaction demonstrated high regioselectivity and functioned well with both aromatic and aliphatic amines at room temperature.

Photoinduced catalytical reduction of carbonyl compounds using water as a hydrogen source

A photoinduced iridium-catalyzed PPh3/H2O system for the hydrogenation of carbonyl compounds has been developed, providing a sustainable method for the synthesis of primary alcohols, secondary alcohols, and secondary amines with high atom economy.

DFT investigation of Cu(i)-catalyzed addition of 1,4-pentadiene to acetophenone: mechanism and selectivity for the synthesis of a chiral tertiary alcohol with a 1,3-diene unit

DFT calculations show a clear understanding of the reaction mechanism and the origin of selectivity in the chiral phosphoric acid ligand-controlled Cu(i)-catalyzed addition of 1,4-pentadiene to acetophenone.

Maximizing the number of Rh0–Rh+ sites through metal dispersion control for the synthesis of higher alcohols from syngas

The ratio of Rh+ to Rh0 is regulated by the dispersion of Rh. An appropriate ratio maximizes the number of Rh0–Rh+ sites, resulting in the highest selectivity for higher alcohols.

Pd(II)-catalyzed hydroarylations/hydroalkenylations of terminal alkynes: regioselective synthesis of allylic, homoallylic, and 1,3-diene systems.

A Pd-catalyzed regioselective hydroarylation of terminal alkynes containing a heteroatom has been developed via carbopalladation for the synthesis of allylic ethers, amines, and homoallylic alcohols. Moreover, hydroalkenylation of alkynes produces a variety of stereodefined 1,4-dienes with high regioselectivity. The important features of the present protocol are that it is highly regioselective, operationally rapid, and scalable with a huge substrate scope using only 3 mol% of PdCl2(PPh3)2 catalyst in the presence of a mild base KOAc.

Selective synthesis of cyclic alcohols from cycloalkanes using nickel(ii) complexes of tetradentate amidate ligands.

Selective functionalisation of hydrocarbons using transition metal complexes has evoked significant research interest in industrial chemistry. However, selective oxidation of unactivated aliphatic C-H bonds is challenging because of the high bond dissociation energies. Herein, we report the synthesis, characterisation and catalytic activity of nickel(ii) complexes ([Ni(L1-L3)(OH2)2](ClO4)2 (1-3)) of monoamidate tetradentate ligands [L1: 2-(bis(pyridin-2-ylmethyl)amino)-N-phenylacetamide, L2: 2-(bis(2-pyridin-2-ylmethyl)amino)-N-(naphthalen-1-yl)acetamide, L3: N-benzyl-2-(bis(pyridin-2-ylmethyl)amino)acetamide] in selective oxidation of cycloalkanes using m-CPBA as the oxidant. In cyclohexane oxidation, catalysts showed activity (TON) in the order 1 (654) > 2 (589) > 3 (359) with a high A/(K + L) ratio up to 23.6. Using catalyst 1, the substrate scope of the reaction was broadened by including other cycloalkanes such as cyclopentane, cycloheptane, cyclooctane, adamantane and methylcyclohexane. Further, the Fenton-type reaction in the catalytic cycle was discarded based on the relatively high 3°/2° ratio of 8.6 in adamantane oxidation. Although the formation of chlorinated products during the reactions confirmed the contribution of the 3-chlorobenzoyloxy radical mechanism, the high alcohol selectivity obtained for the reactions indicated the participation of nickel-based oxidants in the oxidation process.

Ru-catalyzed asymmetric hydrogenation of α,β-unsaturated ketones via a hydrogenation/isomerization cascade.

Ru-catalyzed asymmetric hydrogenation of α-substituted α,β-unsaturated ketones has been developed for the enantioselective synthesis of chiral α-substituted secondary alcohols with high diastereo- and enantioselectivities (up to >99 : 1 dr, 98% ee). Mechanistic experiments suggest that the reaction proceeds via a Ru-catalyzed asymmetric hydrogenation of the CO bond in concert with a base-promoted allylic alcohol isomerization, and the final stereoselectivities were controlled by a DKR process during the asymmetric hydrogenation of the ketone intermediate.

Iridium(III)-catalyzed photoredox cross-coupling of alkyl bromides with trialkyl amines: access to α-alkylated aldehydes.

A C(sp3)-C(sp3) cross coupling approach based on an iridium-photocatalytic radical process has been developed enabling the synthesis of various α-alkylated aldehydes from easily available/synthesized alkyl bromides and trialkyl amines under mild photocatalytic conditions. The synthesized aldehydes are also explored as a functional handle for various useful products such as carboxylic acid, alcohol and N-heterocycle synthesis.

Co–Co2C catalysts supported on carbon-coated ordered mesoporous silica with promoted CO insertion and C–C coupling for higher alcohol synthesis from syngas

Co–Co2C catalysts supported on carbon-coated ordered mesoporous silica showed superior performance for HAS than catalysts with uncoated and amorphous supports.

Alcohol synthesis based on the SN2 reactions of alkyl halides with the squarate dianion.

A convenient method has been developed for transforming alkyl halides into the corresponding alcohols via an SN2 reaction. Treatment of an alkyl halide with the squarate dianion at high temperature produces mono-alkyl squarate, and a one-pot basic hydrolysis of the intermediate affords the alcohol in good yield.

Tuning CuO crystallite size by different solvents for higher alcohols synthesis from syngas over CuZnAl catalyst

The crystallite size effect of metal oxides plays a vital role in the field of heterogeneous catalysis research. Herein, CuZnAl catalysts with varying CuO crystallite sizes are synthesized by coprecipitation method employing various solvents. The catalytic performance of CO hydrogenation is studied and the physical and chemical properties of catalysts are characterized by XRD, H2-TPR, N2 adsorption-desorption, and NH3/CO2-TPD-MS. The results indicate that the different types of solvents can effectively regulate CuO crystallite size, thereby affecting its reducibility and catalytic activity. Most importantly, we observe that CuO crystallite size is positive correlated with reduction temperature and negative correlated with C2+OH selectivity. The catalyst employing ethanol as a solvent exhibits the highest CO conversion (22.91 %) and the optimum proportion of C2+OH in total alcohols (18.96 %), which indicates that smaller CuO crystallite size facilitates reduction of Cu species and generation of larger pore size as well as suitable acid-basic sites, thereby promoting higher alcohols formation. Therefore, these findings greatly broaden understanding the size effect of CuO, providing a new strategy for rational design Cu-based catalysts for higher alcohols synthesis.

The engineering of CO2 hydrogenation catalysts for higher alcohol synthesis

Anthropogenic CO2 emissions have drawn significant attention in recent years. Using CO2 as feedstock for chemical processes has become a key solution in overall closed carbon cycles for a vision...

Photoredox and NHC Enabled Deoxygenative Alcohol Homologation via Formal 1,2-Addition.

A highly efficient photoinduced iron-catalyzed method has been developed for the direct use of alcohols as surrogates for organometallic reagents in the synthesis of tertiary alcohols. This method can be applied to both primary and secondary alcohols with diverse structures, enabling their reaction with aryl ketones under mild conditions. A variety of functional groups, including those that are typically reactive under conventional tertiary alcohol synthesis conditions, are compatible. Mechanistically, this reaction proceeds through the direct addition of the radical to the carbonyl pathway.

Biocatalytic hydroxylation tertiary C-H bonds for synthesis of chiral tertiary alcohols by cytochrome P450

In view of the importance and beneficial characteristics of enantioenriched tertiary alcohols in pharmaceutical chemistry, efficient and green strategies for their synthesis are highly sought after. Here, we report a simple synthesis of the elusive chiral tertiary alcohols. A cytochrome P450 monooxygenase called P450PL2 was developed to enable chiral tertiary alcohols by the benzylic CH bonds asymmetric hydroxylation of the racemic tertiary carbon substrates. This P450-catalyzed protocol provides various chiral tertiary alcohols with unexpectedly functional group tolerance and excellent enantioselectivities (up to >99 % ee). The method features mild reaction and employs molecular oxygen as an oxidant, avoids the use of pre-oxygen functionalized substrates. Preliminary molecular dynamics simulation studies were carried out to reveal the possible reasons for the exceptional selective hydroxylation of substrate during P450PL2 catalysis.

THE IMPACT OF STILLAGE FILTRATE ON THE SYNTHESIS OF VOLATILE IMPURITIES OF ALCOHOL AND THE OPTIMIZATION OF THE RECTIFICATION PROCESS

The aim of this research is to determine the influence stillage filtrate on the synthesis of volatile impurities in alcohol, with subsequent removal through the rectification process in a rectification unit operating in an energy-saving mode at pressures lower than atmospheric. The study was conducted at the state enterprise (hereinafter - SE) "Kozlivsky Distillery" located at: Ternopil region, Kozlivsky district, urban-type settlement Kozliv, using gas chromatographic method for determining the content of microcomponents (acetaldehyde, methanol, fusel oil components, esters) using capillary columns. The rectification unit includes various components such as the mash column, hydroselection column, rectification column, methanol column, impurity concentration column and "zero" column. During the research, technological parameters of operation of each unit component were studied, and the concentration of organic impurities in alcohol at different stages was determined. The results of this study allow improving the efficiency of the rectification unit, which is of great importance in alcohol production. Research was conducted on the impact stillage filtrate on the synthesis of volatile impurities in alcohol during fermentation. The research was carried out with the full use iltrate of stillage at the stage of preparing the fermenting substrate. The mash had different concentrations of dry substances. The stillage filtrate was obtained by centrifugation of native stillage and its suspended matter concentration did not exceed 1%. The influence of the amount stillage filtrate and the number of cycles of its recirculation on the biosynthesis of volatile organic compounds during fermentation was studied. The research results showed that the use stillage filtrate at the stage of preparing the fermenting substrate contributes to reducing water consumption and slows down the synthesis of acetaldehyde and higher alcohols during fermentation. With repeated use stillage filtrate, the synthesis process changes, which affects the concentration of volatile organic compounds in the fermentation mash. This impact should be taken into account when selecting operating modes of the rectification unit. Therefore, to obtain high-quality rectified alcohol, it is necessary to adjust the appropriate operating mode of the rectification unit and consider the influence stillage filtrate on the fermentation process.

Brønsted-Acid-Catalyzed Enantioselective Desymmetrization of 1,3-Diols: Access to Chiral β-Amino Alcohol Derivatives.

Herein, we describe a Brønsted-acid-catalyzed enantioselective desymmetrization of 1,3-diols with alkynes through a hydroalkoxylation/hydrolysis process. The reaction leads to the atom-economical synthesis of valuable chiral β-amino alcohols under mild reaction conditions. Further synthetic transformations based on the β-amino alcohol moiety provide divergent approaches toward chiral N-containing heterocycles.

Efficient and Recyclable Photobiocatalytic System via Cofactor Regeneration for Chiral Aryl Alcohol Synthesis

Efficient and Recyclable Photobiocatalytic System via Cofactor Regeneration for Chiral Aryl Alcohol Synthesis

The synthesis of higher-carbon sugar alcohols via indium-mediated acyloxyallylation as potential phase change materials

AbstractIn recent years, sugar alcohols have gained significant attention as organic phase change materials (PCMs) for thermal energy storage due to their comparably high thermal storage densities up to 350 J/g. In a computational study, outstandingly high values of up to ~ 450500 J/g have been postulated for specific higher-carbon sugar alcohols. These optimized structures feature an even number of carbon atoms in the backbone and a stereochemical configuration in which all hydroxyl groups are in an 1,3-anti-relationship, as found in the natural hexitol d-mannitol. However, these manno-configured higher-carbon sugar alcohols have not been experimentally investigated as PCMs yet and described synthetic routes are elaborate multiple steps syntheses. Therefore, we aimed to synthesize sugar alcohols of the manno-series with a concise synthetic protocol based on the indium-mediated acyloxyallylation (IMA) of aldoses. En route the C2-epimers were easily accessible, namely gluco-configured sugar alcohols, bearing one set of hydroxyl groups in a suboptimal 1,3-syn-realtionship. The synthesized compounds were found to possess thermal properties consistent with the predicted values, and the “perfect” higher-carbon sugar alcohol with eight carbon atoms was found to have indeed an outstanding high latent heat of fusion of ~ 380 J/g with a melting point of 260 °C. Graphical abstract