Benzyl Alcohol In Water Research Articles

A mild and efficient THP protection of indazoles and benzyl alcohols in water

A mild and efficient method for THP protection of indazoles and benzyl alcohols has been developed in water, the most environmentally friendly solvent, in which Tween 20 (2% w/w) was added to form aqueous micelles to increase the solubility of starting materials. This aqueous protocol allowed the reaction to proceed smoothly at room temperature and with only 1.2 equiv of DHP, providing moderate to good yields of THP protected products for a wide scope of substrates. In addition, the methodology was highly practical in the large-scale synthesis (1 g synthesis of 2c as an example), wherein the convenient work-up and purification procedure (simple filtration) made the protocol even more attractive.

Synthesis and characterization of a novel oxo-bridged binuclear iron(iii) complex: its catalytic application in the synthesis of benzoxazoles using benzyl alcohol in water

A novel oxo-bridged binuclear iron(iii) complex was found to be an efficient catalyst in the synthesis of benzoxazoles from benzyl alcohols.

P-Doped carbons derived from cellulose as highly efficient metal-free catalysts for aerobic oxidation of benzyl alcohol in water under an air atmosphere.

P-Doped carbons, prepared by carbonizing phosphoric acid-treated cellulose, exhibit high catalytic activity in metal-free aerobic oxidation of benzyl alcohol to benzaldehyde (99.7% yield) in water under air. A high turnover frequency is obtained due to the doped P-species of C3PO, identified via experiments and DFT calculations.

Preparation of nickel-titanium alloy fiber/organosilicone-polyurethane solid phase microextraction head and its application to the determination of seven substituted benzenes in water

Toluene-2,4-diisocyanate, polyester polyol, and hydroxy silicone oil were used as raw materials; stannous octoate was used as the catalyst; and cyclohexanone was used as the solvent to synthesize organosilicone-polyurethane (SP). The polymer was coated on the surface of a nickel-titanium alloy fiber treated hydrothermally with potassium hydroxide. It was the prepared for headspace solid phase microextraction (HS-SPME). The polymer structure was analyzed by infrared spectroscopy, the highest temperature of the coating was determined by thermogravimetric analysis, and the surface morphology of the extraction head was observed by scanning electron microscopy. The benzene series of toluene, xylene, m-dichlorobenzene, o-dichlorobenzene, ethyl benzoate, nitrobenzene and benzyl alcohol in water were determined by HS-SPME-gas chromatography (GC) method. There was a good linear relationship between the chromatographic peak area and mass concentration of each measured object. The correlation coefficients (R2) were 0.9926-0.9998. The limits of detection were 0.08-0.24 μg/L. The recoveries of the spiked samples were 95.9%-105.4%, and the relative standard deviations were 1.4%-5.0%. The coating of SPME head adhered more firmly, and had a better adsorption performance for the substituted benzenes in water.

Copper-Catalyzed Aerobic Oxidation Reaction of Benzyl Alcohol in Water under Base-Free Condition

Copper-Catalyzed Aerobic Oxidation Reaction of Benzyl Alcohol in Water under Base-Free Condition

Multi-modal surface grafting of [trans-bis(aminodiphenylphosphine) terpyridine-Ru(II)Cl]+Cl− complex onto glassy carbon electrode

The design of a ruthenium-terpyridine complex having 4-aminobenzyl-diphenylphosphine as remote ligands in a trans arrangement ([Ru(trans-PN)2(trpy)Cl]+Cl−, [trans-bis(aminodiphenylphosphine) terpyridine-Ru(II)Cl]+Cl−) is shown to be a highly versatile approach for the immobilization of the organometallics at a carbon surface. Three distinct strategies could be then successfully employed to achieve the grafting of the complex, namely i) the electroreduction of the corresponding in situ produced diazonium cation, ii) the electrooxidation of the aromatic amine moiety in the presence of a base and iii) an anodic electropolymerization in the absence of base. The modified surfaces were characterized by electrochemical or Scanning Electron Microscopy (SEM) studies. The reported approach allows a clean modulation of film thickness and anchoring modes, particularly useful for a given design of ruthenium containing films dedicated to a given application. In this context, the polymer films which contain the largest surface concentration of active ruthenium were employed as immobilized catalyst for oxidation of benzyl alcohol in water, allowing a test of the catalytic activity of the complexes as grafted materials.

Aerobic oxidation of benzyl alcohol in water catalyzed by gold nanoparticles supported on imidazole containing crosslinked polymer

A series of imidazole containing crosslinked copolymer poly(divinylbenzene-co-N- vinylimidazole) (PDVB-VI-n) supported Au catalysts were prepared by using AuCl3 as the precursor. The resulting Au/PDVB-VI-n catalysts were employed to catalyze the aerobic oxidation of benzyl alcohol with molecular oxygen as the sole oxidant and water as the solvent. By optimizing the sizes of Au NPs and the composition of PDVB-VI-n, Au/PDVB-VI-n exhibited the excellent activities even only using a small amount of basic K2CO3. Interestingly, the conversion of benzyl alcohol increased monotonously with the increase of Au sizes in the range of 2–5nm, but the selectivity to benzoic acid increased first and then decreased gradually. The highest selectivity to benzoic acid of ∼80%was achieved over ∼3.2nm Au NPs.

Water-soluble heteropolyacid-based ionic liquids as effective catalysts for oxidation of benzyl alcohol in water with hydrogen peroxide

AbstractA series of organic-inorganic composite catalysts were prepared by modifying tungstophosphoric acid (H

Dual roles of sulfonyl hydrazides in the catalyst-free sulfonylation of unsaturated benzylic alcohols in water

An atom-economical sulfonylation of unsaturated benzylic alcohols in water is described.

Copper(II) nanoparticles: an efficient and reusable catalyst in green oxidation of benzyl alcohols to benzaldehydes in water

Copper(II) nanoparticles immobilized onto 3‐aminopropyltriethoxysilane (APTES) supported on mesoporous silica KIT‐5 nanocomposite (AK) was prepared. The APTES group on KIT‐5 was manipulated as a suitable coordinating agent for copper(II) and fully characterized using FT‐IR, SEM, EDX, ICP, TGA, XRD and UV–visible methods. Moreover, a quantitative description for metal–ligand interactions in the APTES‐KIT‐5 mesoporous silica‐supported copper(II) acetate complex was assessed via quantum chemistry computations. This novel transition metal supported heterogeneous surface was used as an effective catalyst in low loading for selective oxidation of differently substituted benzylic alcohols in water, using H2O2as oxidant to give the corresponding carbonyl compounds in high to excellent yields. This heterogeneous nanocatalyst can be recovered and reused several times without any significant loss of activity. Copyright © 2016 John Wiley & Sons, Ltd.

A recoverable sandwich phosphorotungstate stabilized palladium (0) catalyst for aerobic oxidation of alcohols in water

The preparation, characterization and catalytic properties of tetra metal substituted sandwich phosphorotungstate [M4(H2O)2(PW9O34)2]10−(M4P2W18, M2+=Fe2+, Co2+, Mn2+, Cu2+, VO2+) stabilized Pd nanoparticles, which were in-situ encapsulated in mesoporous aluminum phosphate (mAPO) by a one-pot method, were demonstrated for aerobic oxidation of alcohol in water. The synthesized catalysts were characterized with N2 adsorption, XRD, TEM, FT-IR and UV–vis. TEM analysis revealed that Pd-M4P2W18/mAPO thus obtained has a mean palladium particle size of less than 5nm. The solid Pd-M4P2W18/mAPO catalysts exhibit excellent activity for aerobic oxidation of benzyl alcohols in water without any base additives. It was found the introduced M4P2W18 polyoxanions encapsulated palladium nanoparticles as both stabilizing agent and promoters, leading to enhanced activity and recyclability of palladium catalyst. The recycling test of representative Pd-(VO)4P2W18/mAPO for oxidation of benzyl alcohol suggested no significant decrease in activity and selectivity even after twelve times of successive reactions. This novel heterogeneous catalyst composed of polyoxometalates stabilized palladium nanocatalysts and mesoporous aluminophosphate can also be extended to the selective oxidation of various alcohols.

ChemInform Abstract: Direct Use of Benzylic Alcohols for Gold(III)‐Catalyzed S‐Benzylation of Mercaptobenzoic Acids in Water.

AbstractA gold(III)‐catalyzed direct substitution of benzylic alcohols in water is presented.

Direct Use of Benzylic Alcohols for Gold(III)‐Catalyzed S‐Benzylation of Mercaptobenzoic Acids in Water

AbstractWe demonstrate the gold(III)‐catalyzed direct substitution of benzylic alcohols in water. These atom economic and environmentally benign protocols afford S‐benzylated products in moderate to excellent yields. In contrast, common Lewis or Brønsted acids as catalyst, and organic solvents such as dichloromethane or toluene were ineffective for the S‐benzylation of mercaptobenzoic acids. Water can be an attractive tool for new transition metal‐catalyzed reactions. A Hammett study for the rate constants with various substituted alcohols shows a good correlation (R2=0.97) between the log(kX/kH) and the σ+ value of the respective substituents. From the slope negative ρ values of 2.35 are obtained, suggesting that there is a build‐up of positive charge in the transition state. Our catalytic system can be performed with the use of only 2 mol% of gold(III) catalyst without any other additives in water, and scaled up to 10 mmol scale (85% isolated yield). Notably, the present method can accomplish the S‐benzylation of unprotected mercaptobenzoic acids, which is chemoselective and leaves the carboxyl group intact. Furthermore, the direct substitution of allylic and propargylic alcohols also proceeded smoothly in good yields.magnified image

Imidazolium chloride immobilized on copper acetylacetonate-grafted magnetic chitosan as a new metal/ionic liquid bifunctional catalyst for selective oxidation of benzyl alcohols in water

Copper acetylacetonate and 1-methyl-3-propyl imidazolium chloride immobilized on chitosan magnetic nanoparticlesviacovalent attachment as dual metal–ionic liquid catalyst for selective oxidation of benzyl alcohols under mild and co-catalyst free conditions.

Metal ion-modified TiO2 photocatalysts having controllable oxidative performance under irradiation of visible light

Metal ion-modified TiO2 photocatalysts designated by combinations of various metal ions and TiO2 powders that respond to visible light and exhibit controllable photocatalytic oxidative performances were examined. The photocatalytic oxidative performances were evaluated by selective oxidation of benzyl alcohol in water in the presence of O2 under irradiation of visible light. The TiO2 samples modified with Ru3+, Pd2+ and Rh3+ (Ru3+/TiO2, Pd2+/TiO2 and Rh3+/TiO2) exhibited high levels of photocatalytic activity. The effects of metal ions and the kind of TiO2 on photocatalytic performances of Rh3+/TiO2 and Ru3+/TiO2 were investigated in detail.

ChemInform Abstract: N‐Functionalized Amino Acids Promoted Aerobic Copper‐Catalyzed Oxidation of Benzylic Alcohols in Water.

AbstractPrimary and secondary benzylic alcohols are converted in their corresponding aldehydes or ketones using an efficient Cu/TEMPO/N‐functionalized amino acid catalyzed aerobic alcohol oxidation system in water.

Palladium‐Catalyzed Benzylic CH Benzylation via Bis‐Benzylpalladium(II) Complexes in Water: An Effective Pathway for the Direct Construction of N‐(1,2‐Diphenylethyl)anilines

AbstractA strategy for the N‐benzylation/benzylic CH benzylation cascade of anilines by the π‐benzylpalladium system using a water‐soluble palladium(0)/sodium diphenylphosphinobenzene‐3‐sulfonate (TPPMS) catalyst and benzyl alcohol in water has been developed. This tandem process is devised as a novel and efficient synthetic route for N‐(1,2‐diphenylethyl)anilines. Benzylic CH activation of a mono‐N‐benzylated intermediate with a π‐benzylpalladium(II) complex affords a bis‐π‐benzylated palladium(II) intermediate. The nucleophilic η1‐σ‐benzyl anion ligand attacks the electrophilic η3‐π‐benzyl ligand to give a dibenzylated product. The intermolecular competition between mono‐N‐benzylaniline and its monodeuterated form (monodeuterated at the benzylic group) with benzyl alcohol gave a KIE=4.6, suggesting that CH bond cleavage was involved in the rate‐determining step. Hammett studies on the rate constants of benzylation by various substituted anthranilic acids and mono‐N‐benzylanilines show a good correlation between the log(kX/kH) and the σ values of the respective substituents. From the slope, negative ρ values are obtained, suggesting that there is a build‐up of positive charge in the transition state. The reaction of anilines with electron‐donating and electron‐withdrawing groups affords the corresponding N‐(1,2‐diphenylethyl)anilines in moderate to good yields (54–86%). Interestingly, the reaction of anthranilic acids proceeded smoothly to give only the corresponding dibenzylated products in good to excellent yields (70–87%). The carboxyl group of the anthranilic acids acts as a directing group in the benzylic CH activation process.magnified image

N-Functionalized Amino Acids Promoted Aerobic Copper-Catalyzed Oxidation of Benzylic Alcohols in Water

Instead of traditional N,N-bidentate ligands, N-functionlized amino acids were used as powerful N,O-bidentate ligands in aerobic copper/TEMPO-catalyzed system for promoting oxidation of benzylic alcohols. Under the optimized reaction conditions, a wide range of primary and secondary benzylic alcohols have been efficiently converted into aldehydes and ketones with good to excellent yields in water.

Synthesis and electrochemical studies of carbon-modified LiNiPO4 as the cathode material of Li-ion batteries

Well-crystallized olivine LiNiPO4 and carbon-modified LiNiPO4(LiNiPO4/C) were synthesized by a combined solvothermal and solid state reaction method using water-benzyl alcohol two-phase solvent. The structure and morphology of the prepared LiNiPO4 were systematically characterized by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The LiNiPO4 particles are up to around 2 μm in diameter while the particle size of LiNiPO4/C is about 100–200 nm. At a current rate of 0.05 C(1.00 C=167 mA/g, corresponding to one Li+ intercalation/deintercalation), LiNiPO4 and LiNiPO4/C presented a high initial specific capacity of 157 and 220 mA·h/g, respectively. The capacity of LiNiPO4/C is 72% larger than that of LiNiPO4 at 0.1 C. The LiNiPO4/C cathode exhibits a superior electrochemical performance in comparison with LiNiPO4, revealing that carbon modifying is an effective method to improve the ionic diffusion and electronic conductivity of cathode material LiNiPO4. Furthermore, lithium ion diffusion coefficients of LiNiPO4 and LiNiPO4/C are 1.80×10−15 and 1.91×10−14 cm2/s, respectively, calculated via the data from electrochemical impedance spectra.

ChemInform Abstract: Vanadium‐Catalyzed Green Oxidation of Benzylic Alcohols in Water under Air Atmosphere.

Abstract The oxidation of alcohols using catalytic amounts of metal complexes is highly attractive from the viewpoint of green chemistry principles. However, examples of metal complex-catalyzed oxidations of alcohols with O2 using water as the solvent are still rare, and precious metals, high-pressure O2 or air, and a stoichiometric amount of base are often required. In this study, it was found that an oxovanadium-4,4′-t-Bubpy (4,4′-di-tert-butyl-2,2′-bipyridyl) complex exhibited high catalytic activity in the oxidation of benzhydrols under an atmosphere of O2 in water as the sole solvent. Interestingly, this catalytic oxidation method could be applied to the gram-scale aerobic oxidation of alcohols in water under the atmosphere.