Solvent-free alkylation of dimethyl malonate using benzyl alcohols catalyzed by FeCl_3/SiO_2

Activated methylene compound such as dimethyl malonate reacted readily with benzylic alcohols in the presence of ferric chloride/silica gel mixture （FeCl3/SiO2） under microwave irradiation to produce benzylic derivative of dimethyl malonate in high yields in solvent-free condition. 2009 Mohammad Reza Shushizadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Oxidation of benzyl alcohols to ketones and aldehydes by O3 process enhanced using high-gravity technology

In this study,a practical process for ozonization of benzyl alcohols to ketones and aldehydes in a rotating packed bed(RPB-O3)reactor has been developed.Using 1-phenylethanol as a model reactant,the performance of RPB-O3 process in different solvents has been compared with the commonly used stirred tank reactor(STR-O3).Ethyl acetate was the optimum solvent for the conversion of 1-phenylenthanol to acetophenone in RPB-O3 process,with 78%yield after 30 min.In a parallel STR-O3 experiment,the yield of acetophenone was50%.Other experimental variables,i.e.O3 concentration,reaction time,high-gravity factor and liquid flow rate were also optimized.The highest yield of acetophenone was obtained using O3 concentration of 80 mg·L-1,reaction time of 30 min,high gravity factor of 40 and liquid flow rate of 120 L·h-1.Under the optimized reaction conditions,a series of structurally diverse primary and secondary alcohols was oxidized with(19%–92%)yield.The ozonization mechanism was studied by Electron Paramagnetic Resonance(EPR)spectroscopy,monitoring the radical species formed upon self-decomposition of O3.The characteristic quadruple peak with the 1:2:2:1 intensity ratio that corresponds to hydroxyl radicals(·OH)was observed in the electron paramagnetic resonance(EPR)spectrum,indicating an indirect oxidation mechanism of alcohols via·OH radical.

CaY-zeolite Catalyzed Etherification and Alkylation of Substituted Benzyl Alcohols

The reaction of p- and/ α-subtituted benzyl alcohols in CaY-zeolite produced the corresponding dibenzyl ethers and/or benzyl toluenes as the principal products.

Selective oxidation of benzyl alcohols to benzoic acid catalyzed by eco-friendly cobalt thioporphyrazine catalyst supported on silica-coated magnetic nanospheres

A novel magnetically recoverable thioporphyrazine catalyst（CoPz（S-Bu）8/SiO2@Fe3O4） was prepared by immobilization of the cobalt octkis（butylthio） porphyrazine complex（CoPz（S-Bu）8） on silica-coated magnetic nanospheres（SiO2@Fe3O4）. The composite CoPz（S-Bu）8/SiO2@Fe3O4appeared to be an active catalyst in the oxidation of benzyl alcohol in aqueous solution using hydrogen peroxide（H2O2） as oxidant under Xe-lamp irradiation,with 36.4% conversion of benzyl alcohol, about 99% selectivity for benzoic acid and turnover number（TON） of 61.7 at ambient temperature. The biomimetic catalyst CoPz（S-Bu）8was supported on the magnetic carrier SiO2@Fe3O4 so as to suspend it in aqueous solution to react with substrates, utilizing its lipophilicity. Meanwhile the CoPz（S-Bu）8can use its unique advantages to control the selectivity of photocatalytic oxidation without the substrate being subjected to deep oxidation. The influence of various reaction parameters on the conversion rate of benzyl alcohol and selectivity of benzoic acid was investigated in detail. Moreover, photocatalytic oxidation of substituted benzyl alcohols was obtained with high conversion and excellent selectivity, specifically conversion close to 70%, selectivity close to 100% and TON of 113.6 for para-position electron-donating groups. The selectivity and eco-friendliness of the biomimetic photocatalyst give it great potential for practical applications.

Different efficiency toward the biomimetic aerobic oxidation of benzyl alcohol in microchannel and bubble column reactors: Hydrodynamic characteristics and gas–liquid mass transfer

The selective aerobic oxidation of benzyl alcohol to benzaldehyde has attracted considerable attention because benzaldehyde is a high value-added product. The rate of this typical gas–liquid reaction is significantly affected by mass transfer. In this study, CoTPP-mediated(CoTPP: cobalt(II) mesotetraphenylporphyrin) selective benzyl alcohol oxidation with oxygen was conducted in a membrane microchannel(MMC) reactor and a bubble column(BC) reactor, respectively. We observed that 83% benzyl alcohol was converted within 6.5 min in the MMC reactor, but only less than 10% benzyl alcohol was converted in the BC reactor. Hydrodynamic characteristics and gas–liquid mass transfer performances were compared for the MMC and BC reactors. The MMC reactor was assumed to be a plug flow reactor,and the dimensionless variance was 0.29. Compared to the BC reactor, the gas–liquid mass transfer was intensified significantly in MMC reactor. It could be ascribed to the high gas holdup(2.9 times higher than that of BC reactor), liquid film mass transfer coefficient(8.2 times higher than that of BC reactor), and mass transfer coefficient per unit interfacial area(3.8 times higher than that of BC reactor). Moreover,the Hatta number for the MMC reactor reached up to 0.61, which was about 15 times higher than that of the BC reactor. The computational fluid dynamics calculations for mass fractions in both liquid and gas phases were consistent with the experimental data.

Catalytic Performance of MnOx Nanorods in Aerobic Oxidation of Benzyl Alcohol

Various manganese oxide nanorods with similar one-dimensional morphology were prepared by calcination of MnOOH nanorods under different gas atmosphere and at different temper- atures, which were synthesized by a hydrothermal route. The morphology and structure of MnOx catalysts were characterized by a series of techniques including X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and tempera- ture programmed reduction （TPR）. The catalytic activities of the prepared MnO~ nanorods were tested in the liquid phase aerobic oxidation of benzyl alcohol, which follow a sequence as MnO2〉Mn203~Mn304〉MnOOH with benzaldehyde being the main product. On the basis of H2-TPR results, the superior activity of MnO2 is ascribed to its lower reduction temperature and therefore high oxygen mobility and excellent redox ability. Moreover, a good recycling ability was observed over MnO2 catalysts by simply thermal treatment in air.

Efficient oxidation of benzyl alcohol with heteropolytungstate as reaction-controlled phase-transfer catalyst

A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the properties of reaction-controlled phasetransfer catalysis, and they had excellent catalytic ability to the oxidation of benzyl alcohol. No other by-products were detected by gas chromatography. Once the hydrogen peroxide was consumed completely, the catalyst precipitated from solvent, and the results of the catalyst recycle showed that the catalyst had high stability.

Selective suppression of toluene formation in solvent-free benzyl alcohol oxidation using supported Pd-Ni bimetallic nanoparticles

The solvent‐free oxidation of benzyl alcohol was studied using supported Pd‐Ni bimetallic nanoparticles.Compared with monometallic Pd,the addition of Ni to Pd was found to be effective in suppressing the nondesired product toluene,thereby enhancing the selectivity towards benzaldehyde.This result was attributed to a dual effect of Ni addition:the weakening of dissociative adsorption of benzyl alcohol and the promotion of oxygen species involved in the oxidation pathway.

Aerobic Oxidation of Benzyl Alcohol Catalyzed by Cu-Mn Mixed Oxides and 2,2,6,6-Tetramethyl-piperidyl-1-oxyl

Heterogeneous Cu-Mn mixed oxides can mediate TEMPO-catalyzed selective oxidation of benzyl alcohol by molecular oxygen under neutral condition, and is recyclable. In the case of the molar ratio of Cu and Mn over 1, the highly-dispersed CuO inside the Cu-Mn mixed oxides is responsible for the good performances in catalytic oxidation.

The Role of Vanadia for the Selective Oxidation of Benzyl Alcohol over Heteropolymolybdate Supported on Alumina

A series of 12-molybdophosphoric acid (MPA) supported on V2O5 dispersed γ-Al2O3 catalysts with different vanadia loadings were prepared by impregnation and characterized by N2 adsorption-desorption, X-ray diffraction, temperature-programmed reduction, in situ laser Raman spectroscopy, UV-Vis diffused reflectance spectroscopy, scanning electron microscopy, and temperature-programmed desorption of NH3 techniques. Their catalytic activities were evaluated for the vapor phase aerobic oxidation of benzyl alcohol. The catalysts exhibited high catalytic activity and the conversion of benzyl alcohol depended on the vanadia content while the catalyst with 15 wt% V2O5 content showed optimum activity. The characterization results suggest the presence of well-dispersed V2O5 and partially disintegrated Keggin ions of MPA on the support. In situ Raman studies showed a reduced Mo(IV) species when the catalysts were calcined at high temperatures. The high oxidation activity of the catalysts is related to the synergistic effect between MPA and V2O5.

Photocatalytic oxidation of primary and secondary benzyl alcohol catalyzed by two coenzyme NAD^+ models

Photocatalytic oxidation of primary and secondary benzyl alcohol to corresponding benzaldehyde or acetophenone using Acr＋Cl04- or PhAcr＋Cl04- as photocatalysts under visible light irradiation at room temperature.

Catalytic Performance of Graphite Oxide Supported Au Nanoparticles in Aerobic Oxidation of Benzyl Alcohol： Support Effect

Various Au/GO catalysts were prepared by depositing Au nanoparticles on thermally- and chemically-treated graphite oxide （GO） supports using a sol-immobilization method. The surface chemistry and structure of GO supports were characterized by a series of analytical techniques including X-ray photoelectron spectroscopy, temperature-programmed desorption and Raman spectroscopy. The results show that thermal and chemical treatments have large influence on the presence of surface oxygenated groups and the crystalline structure of GO supports. A strong support effect was observed on the catalytic activity of Au/GO catalysts in the liquid phase aerobic oxidation of benzyl alcohol. Compared to the amount and the type of surface oxygen functional groups, the ordered structure of GO supports may play a more important role in determining the catalytic performance of Au/GO catalysts.

Weak base favoring the synthesis of highly ordered V-MCM-41 with well-dispersed vanadium and the catalytic performances on selective oxidation of benzyl alcohol

The key to improve the performance of heteroatom catalysts is to ensure the orderliness of catalysts and the good dispersion of heteroatoms.The alkalinity plays the indispensable role in synthetic process of V-MCM-41 catalyst.The excessive alkalinity of synthetic system will make the MCM-41 difficult to crystallize,even to dissolve.It is easy to accumulate for heteroatomic species in the system of low alkalinity.Herein,the highly ordered VMCM-41 with high vanadic content in framework is synthesized in the condition of excessive NH3·H2 O in this paper.A series of characterization results prove the good dispersion of vanadium species,and most of vanadium gets into the framework of MCM-41 with the states of tetravalence and pentavalence.Furthermore,the modified MCM-41 by other transition metals is successful synthesized by the method of V-MCM-41 in this paper.The VMCM-41 shows well catalytic activity for the selective oxidation of benzyl alcohol,which up to 74.83%for the conversion of benzyl alcohol and 96.20%for selectivity of benzaldehyde when initial V/Si=0.10.The paper provides the possibility for industrial application of V-MCM-41 in the oxidation of benzyl alcohol for benzaldehyde.Besides,the work provides a significant idea for the synthesis of modified MCM-41 by well-dispersed transition metals.

Noble-metal-free plasmonic MoO_(3-x)-based S-scheme heterojunction for photocatalytic dehydrogenation of benzyl alcohol to storable H2 fuel and benzaldehyde

Simultaneous generation of H_(2) fuel and value-added chemicals has attracted increasing attention since the photogenerated electrons and holes can be both employed to convert solar light into chemical energy.Herein,for realizing UV-visible-NIR light driven dehydrogenation of benzyl alcohol(BA)into benzaldehydes(BAD)and H_(2),a novel localized surface plasmon resonance(LSPR)enhanced S-scheme heterojunction was designed by combining noble-metal-free plasmon MoO_(3-x) as oxidation semiconductor and Zn_(0.1)Cd_(0.9)S as reduction semiconductor.The photoredox system of Zn_(0.1)Cd_(0.9)S/MoO_(3-x) displayed an unconventional reaction model,in which the BA served as both electron donor and acceptor.The S-scheme charge transfer mechanism induced by the formed internal electric field enhanced the redox ability of charge carriers thermodynamically and boosted charge separation kinetically.Moreover,due to the LSPR effect of MoO_(3-x) nanosheets,Zn_(0.1)Cd_(0.9)S/MoO_(3-x) photocatalysts exhibited strong absorption in the region of full solar spectrum.Therefore,the Zn_(0.1)Cd_(0.9)S/MoO_(3-x) composite generated H_(2) and BAD simultaneously via selective oxidation of BA with high production(34.38 and 33.83 mmol×g^(–1) for H_(2) and BAD,respectively)upon full solar illumination.Even under NIR light irradiation,the H_(2) production rate could up to 94.5 mmol×g^(–1)×h^(–1).In addition,the Zn_(0.1)Cd_(0.9)S/MoO_(3-x) composite displayed effective photocatalytic H_(2) evolution rate up to 149.2 mmol×g^(–1)×h^(–1) from water,which was approximate 6 times that of pure Zn_(0.1)Cd_(0.9)S.This work provides a reference for rational design of plasmonic S-scheme heterojunction photocatalysts for coproduction of high-value chemicals and solar fuel production.

Preparation of Anisotropic MnO2 Nanocatalysts for Selective Oxidation of Benzyl Alcohol and 5-Hydroxymethylfurfural

Anisotropic MnO2 nanostructures,includingα-phase nanowire,α-phase nanorod,δ-phase nanosheet,α+δ-phase nanowire,and amorphous fl occule,were synthesized by a simple hydrothermal method through adjusting the pH of the precursor solution and using diff erent counterions.The catalytic properties of the as-synthesized MnO2 nanomaterials in the selective oxidation of benzyl alcohol(BA)and 5-hydroxymethylfurfural(HMF)were evaluated.The eff ects of micromorphology,phase structure,and redox state on the catalytic activity of MnO2 nanomaterials were investigated.The results showed that the intrinsic catalytic oxidation activity was mainly infl uenced by the unique anisotropic structure and surface chemical property of MnO2.With one-dimensional and 2D structures exposing highly active surfaces,unique crystal forms,and high oxidation state of Mn,the intrinsic activities for MnO2 catalysts synthesized in pH 1,5,and 10 solutions(denoted as MnO2-pH1,MnO2-pH5,and MnO2-pH10,respectively)were twice higher than those of other MnO2 catalysts in oxidation of BA and HMF.With a moderate aspect ratio,theα+δnanowire of MnO2-pH10 exhibited the highest average oxidation state,most abundant active sites,and the best catalytic oxidation activity.

A Novel RP-HPLC Method for Estimating Fulvestrant, Benzoyl Alcohol, and Benzyl Benzoate in Injection Formulation

For the quantitative determination of Fulvestrant, Benzyl alcohol, and Benzyl benzoate in Fulvestrant injection, an original RP-HPLC approach was developed. The gradient method was developed using HPLC and a Phenomenex Luna C8, 150 × 4.6 mm, i.d 3.0 μm particle size column with a gradient programme of mobile phases A and B. With a flow rate of 1.5 mL/minute, injection volume of 10 μL, and column temperature of 35°C, UV wavelength detection at 254 nm for Benzyl alcohol and Benzoyl Benzoate and 280 nm for Fulvestrant, mobile phase-A consists of DI water and mobile phase-B consists of Acetonitrile. The current study describes a single HPLC method for developing a Fulvestrant (Active), Benzyl alcohol (Cosolvent), and Benzyl Benzoate (Cosolvent) assay for Fulvestrant injection. The assay method was determined to be suitable for quantifying three components in the pharmaceutical product and was verified according to ICH guidelines.

SYNTHESIS OF 3-BENZYL-GLYCERIC ACID:A KEY INTERMEDIATE OF A NOVEL CYCLIC ESTER MONOMER

A route was proposed to synthesize 3-benzyl-glyceric acid (3-BGA) as an important intermediate for the synthesis of a novel six-membered cyclic ester monomer-3-benzyloxymethyl-1,4-dioxane-2,5-dione (3-BMG). According to this route, 3-BGA was obtained from ring-opening reaction of benzyl alcohol with methyl glycidate, which was prepared from the epoxidation of methyl acrylate using sodium hypochlorite as the oxidant.

Controllable surface reconstruction of copper foam for electrooxidation of benzyl alcohol integrated with pure hydrogen production

Electrocatalytic water splitting that is coupled with electrocatalytic chemical oxidation is considered as one of the promising methods for efficiently obtaining hydrogen energy and fine chemicals.Herein,we focus on an electrochemical redox activation strategy to rationally manipulate the microstructure and surface valence states of copper foam(CF)and boost the corresponding performance towards electrocatalytic benzyl alcohol oxidation(EBA),accompanied by the efficient hydrogen production.Correspondingly,the Cu(II)‐dominated species are gradually formed on the CF surface with the dissolution and redeposition of copper in the suitable potential range.The new species containing Cu2O,CuO,and Cu(OH)2 during surface reconstruction process of the CF were confirmed by multiple characterization techniques.After 220‐cycled activation(CF‐220),the activated CF achieves an increase of current density for EBA in anode from 9.5 for the original CF to 29.3 mmol/cm2,while the pure hydrogen yield increases threefold than that of the original CF at 1.5 VRHE.The produced new species can endow the CF‐220 with abundant acidity sites,which can enhance the adsorption toward Lewis‐basicity benzyl alcohol,confirmed by NH3‐temperature‐programmed desorption.In situ Raman result further reveals that the as‐produced CuO,Cu(OH)2,and Cu(OH)42−are the main active species toward the EBA process.

Biotransformation of Gastrodin by Mucor spinosus

Microbial transformation of gastrodin by Mucor spinosus strain 3.3450, resulted in a product with a transformation rate close to 100 per cent. This product was identified as p-hydroxy benzyl alcohol on the basis of its 1H, 13C NMR and EI-MS spectral data. It could be inferred that the enzyme responsible for the biotransforma-tion reaction was a kind of extracellular and constitutive enzyme since the transformation reaction of the substrate could be carried out in cell free extracts of the fermentation broth of the Mucor spinosus.

Highly efficient synthesis of benzyl benzoate directly from self-coupling of benzyl alcohol in water

Benzyl benzoate(BB),an important ester,still demands for green synthesis routes.In this work,by size regula-tion and proper functionalization of carbon nanotubes(CNTs)as the support of gold catalyst,this ester can be synthesized very efficiently directly from benzyl alcohol via oxidative coupling.More attractively,the reaction is performed using water as green solvent and molecular oxygen as green oxidant.Simultaneously,very high selectivity to BB can be obtained near full conversion within very short reaction time(just 0.5 h),while the low-value benzoic acid byproduct is negligible.This is very different from many reported gold catalysts that yield much benzoic acid and/or benzaldehyde in water.The results show that,besides the size of CNTs(length and diameter),the functionalization of CNTs is also critical for improving both conversion and the selectivity to BB.In addition,the reaction mechanism for forming BB ester is put forward as well.