- Catalytic oxidation of benzyl alcohols by new Cu(II) complexes of 1,3-oxazolidine based ligand obtained from a solvent free reaction
-
A new 1,3-oxazolidine based ligand, (2-pyridin-2-yl-1,3-oxazolidine-4,4-diyl)dimethanol (H3L), has been synthesized from the reaction of 2-amino-2-(hydroxymethyl)-1,3-propanediol and 2-pyridinecarboxaldehyde at 110 °C. Two mononuclear Cu(II) complexes, [Cu(H3L)Cl2]·CH3OH (1) and [Cu(H3L)2]·2Cl (2), have been synthesized with a similar procedure by the reaction of H3L and CuCl2·H2O in 1:1 and 2:1 M ratios in methanol. The ligand and complexes have been characterized by elemental analysis and spectroscopic methods. The structure of complexes has been characterized by single-crystal X-ray diffraction analysis which showed the copper ion has a distorted square pyramidal geometry in 1 and distorted octahedral geometry in 2. The 1,3-oxazolidine ligand acts as a neutral tridentate N2O-donor ligand in both 1 and 2. Two chloride anions remain coordinated to Cu(II) ion in complex 1, but they act as counter ions in complex 2. The catalytic activity of these complexes has been investigated in the oxidation of benzyl alcohol by using H2O2 or TBHP as oxidant. The effects of some influential parameters in catalytic reactions like molar ratio of oxidant-to-substrate, temperature, nature of oxidant and solvent have been studied to obtain the optimum condition. Moreover, the effects of chlorine substituent on the phenyl group (ortho-, meta- and para-positions) has also been explored. The results of these studies show that both 1 and 2 catalyze the oxidation of benzyl alcohol derivatives to the corresponding benzaldehydes and a little amount of the related benzoic acids, produced by over oxidation of benzaldehyde, are also detected in the reaction mixtures. The results indicate that the selectivity and the activity of these catalytic systems depend on the reaction conditions and the steric and electronic properties of the reagents.
- Bikas, Rahman,Ajormal, Fatemeh,Emami, Marzieh,Noshiranzadeh, Nader,Kozakiewicz, Anna
-
-
Read Online
- Selective oxidation of benzylic alcohols and ethers and oxidative cleavage of benzylic tetrahydropyranyl and trimethylsilyl ethers to their carbonyl compounds by dinitrogen tetroxide-impregnated activated charcoal (N 2O4/charcoal)
-
Benzylic alcohols and ethers were oxidized to their corresponding carbonyl compounds using dinitrogen tetroxide impregnated on activated charcoal (N 2O4/ charcoal) in CH2Cl2 at room temperature. Efficient oxidative cleavage of trimethylsilyl (TMS) and tetrahydropyranyl (THP) ethers to their corresponding carbonyl compounds was also performed by this reagent. High selectivity was observed for oxidation of benzylic alcohols and ethers and also trimethylsilyl ethers in the presence of tetrahydropyranyl ethers. Copyright Taylor & Francis, Inc.
- Iranpoor, Nasser,Firouzabadi, Habib,Pourali, Ali Reza
-
-
Read Online
- A new application of N-bromosaccharin as a selective and efficient oxidative reagent for regeneration of carbonyl compounds from oximes
-
A new method for the direct conversion of various oximes into aldehydes and, ketones by treatment with N-bromosaccharin is described. N-bromosaccharin can be used for an effective, selective and mild oxidizing agent for the regeneration of carbonyl compounds from oximes in good yield.
- Khazaei, Ardeshir,Manesh, Abbas Amini,Rostami, Amin
-
-
Read Online
- A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids leading to chlorinated arenes
-
A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids with inexpensive N-chlorosuccinimide (NCS) was achieved in MeCN in the presence of 10 mol% of l-proline-functionalized MCM-41-immobilized copper(i) complex [MCM-41-l-proline-CuCl] under mild conditions, yielding a variety of aryl chlorides in excellent yields. This method proved to be tolerant of a broad range of functional groups and particularly useful for the conversion of electron-deficient arylboronic acids to aryl chlorides, a transformation that is inefficient without copper catalysis. This heterogeneous copper catalyst can be recovered by a simple filtration of the reaction solution and recycled for at least 10 times without any decreases in activity.
- He, Wen,Zhang, Rongli,Cai, Mingzhong
-
-
Read Online
- Selective oxidation of benzylic substrates to their corresponding carbonyl compounds with 3,6-Bis(triphenylphosphonium)cyclohexene peroxodisulfate
-
3,6-Bis(triphenylphosphonium)cyclohexene peroxodisulfate (BTPCP) was found to be a highly effective and selective oxidant for the conversion of benzyl monohalides, nitrils, and amines to their corresponding carbonyl compounds under mild and neutral conditions.
- Badri, Rashid,Soleymani, Mousa
-
-
Read Online
- Aqueous electrosynthesis of carbonyl compounds and the corresponding homoallylic alcohols in a divided cell
-
An aqueous paired electrosynthesis is studied in a divided cell. On graphite anode Br- was oxidized to Br2 and this generated Br2 oxidized alcohols to the corresponding carbonyl compounds while Sn2+ was reduced
- Zhang, Li,Zha, Zhenggen,Wang, Zhiyong,Fu, Shengquan
-
-
Read Online
- Clean and Selective Oxidation of Alcohols with Oxone and Phase-Transfer Catalysts in Water
-
Abstract: A new, simple, metal-free, and eco-friendly procedure has been proposed forthe oxidation of alcohols with Oxone (potassium peroxymonosulfate) in water inthe presence of six phase-transfer catalysts (PTC). Phase-transfer catalystswere found to display high catalytic activity in water solution. Furthermore,the oxidation of alcohols was also carried out with relatively good conversionand selectivity in water without any catalyst.
- An, X. Q.,Kang, M.,Ma, H. C.,Yang, Y. X.,Yang, Z. W.,Zeng, W.
-
-
Read Online
- Aerobic oxidation of benzyl- and allylic alcohols under visible light irradiation of a fluorescent lamp in the presence of catalytic iodine
-
Benzyl alcohols and allylic alcohols were found to be oxidized to the corresponding aldehydes in the presence of a catalytic amount of iodine under irradiation of a fluorescent lamp.
- Nakayama, Hiroki,Itoh, Akichika
-
-
Read Online
- Metabolic and chemical studies on N-(4-chlorobenzyl)-N'-benzoyhydrazine
-
The in vitro hepatic microsomal metabolism of N-(4-chlorobenzyl)-N'-benzoylhydrazine (CBBAH), a model compound representing N-alkyl substituted hydrazides, was studied using hepatic washed rat microsomal preparations fortified with NADPH to identify the possible N-oxidative, N-dealkylated and hydrolytic metabolites. CBBAH and its potential metabolites were prepared, characterized using spectroscopic techniques and then separated using a reversed phase HPLC system with UV detection at 254 nm. CBBAH was chemically converted to the corresponding hydrazone by m-chloroperbenzoic acid (m-CPBA) oxidation. CBBAH was incubated with rat microsomal preparations in the presence of NADPH, extracted into dichloromethane and evaporated finally under nitrogen. The TLC and HPLC results from the metabolic experiments showed that CBBAH produced the corresponding hydrolytic and N-dealkylated metabolites together with the corresponding hydrazone.
- Kuecuekguezel, S. Gueniz,Kuecuekguezel, Ilkay,Uelgen, Mert
-
-
Read Online
- Heterogeneous photocatalytic anaerobic oxidation of alcohols to ketones by Pt-mediated hole oxidation
-
We report a platinum nanocluster/graphitic carbon nitride (Pt/g-C3N4) composite solid catalyst with a photocatalytic anaerobic oxidation function for highly active and selective transformation of alcohols to ketones. The desirable products were successfully obtained in good to excellent yields from various functionalized alcohols at room temperature, including unactivated alcohols. Mechanistic studies indicated that the reaction could proceed through a Pt-mediated hole oxidation initiating an α-alcohol radical intermediate followed by a two-electron oxidation pathway. The merit of this strategy offers a general approach towards green and sustainable organic synthetic chemistry.
- Sun, Danhui,Li, Peihe,Wang, Xia,Wang, Yingying,Wang, Jinghui,Wang, Yin,Lu, Ye,Duan, Limei,Sarina, Sarina,Zhu, Huaiyong,Liu, Jinghai
-
-
Read Online
- 3-BocNH-ABNO-catalyzed aerobic oxidation of alcohol at room temperature and atmospheric pressure
-
A transition-metal-free catalytic system has been developed for selective transformation of alcohol to aldehydes or ketones. The reactions were performed with 3-(tert-butoxycarbonylamino)-9-azabicyclo[3.3.1]nonane N-oxyl (3-BocNH-ABNO) as the catalyst, NaNO2 as the co-catalyst, molecular oxygen as the terminal oxidant, and AcOH as the solvent under room temperature. This catalytic system exhibited broad functional group tolerance. A series of alcohol substrates, including primary and secondary benzylic alcohols, heteroaromatic analogues, primary and secondary aliphatic alcohols, could be converted into their corresponding aldehydes and ketones in good conversions and selectivities.
- Zhao, Yajing,Li, Yutong,Shen, Zhenlu,Hu, Xinquan,Hu, Baoxiang,Jin,Sun, Nan,Li, Meichao
-
-
Read Online
- Hydroxycarbonylation of Aryl Halides with Formate Salts Catalyzed by Palladium Complexes
-
Substituted aryl halides were hydroxycarbonylated under 50 psi pressure of carbon monoxide in the presence of various formate salts and a homogeneous palladium catalyst to give aromatic acids in good yields.Selectivity of formate salts in hydroxycarbonylation reactions depends on the metallic counter-ion and the reaction conditions.Calcium formate was found to give the highest selectivity for hydroxycarbonylation.A mechanism consisting of the generation of mixed anhydrides as intermediates is suggested.
- Pri-Bar, Ilan,Buchman, Ouri
-
-
Read Online
- Magtrieve: A convenient catalyst for the oxidation of alcohols
-
We find that Magtrieve (CrO2) catalyzes the oxidation of a wide variety of alcohols with periodic acid as the terminal oxidant. Mild conditions, short reaction times, and facile aqueous work-up make this a most attractive method. Olefins are not oxidized under these conditions; thus alcohols react selectively in the presence of alkenes. Conditions have been optimized with respect to catalyst loading, solvent, and co-oxidant; and the scope of the reaction includes primary and secondary benzylic, allylic, and aliphatic alcohols.
- Few, Chip S.,Williams, Kathryn R.,Wagener, Kenneth B.
-
-
Read Online
- Chiral manganese and iron complexes of binaphthyl Schiff bases: Syntheses, crystal structures and asymmetric epoxidation of alkenes
-
The chiral binaphthyl Schiff-base manganese complexes [MnL(X)] [H2L = 2,21-bis(3-R2-5-R 2-2-hydroxybenzylideneimino)-1,1′-binaphthyl; R1 = R2 = Cl, X = O2CMe 1; R1 = Et, R2 = NO2, X = O2CMe 2; R1 = R2 = Cl, X = acac (acetylacetonate) 3] and an iron analogue [FeL(acac)] 4 (R1 = R2 = Cl) have been prepared. The crystal structures of the racemic forms of 3·CH2Cl2 and 4·2H2O exhibit non-planar cis-β configurations with dihedral angles of 85.5 and 72.1° respectively between the two naphthalene rings. Complexes (R)-1 to 3 are active catalysts for the asymmetric epoxidation of alkenes by PhIO. The oxidation of cis-β-methylstyrene by (R)-2 in toluene at -20°C gave an enantiomeric excess of 76%.
- Cheng, Ming-Chuan,Chan, Michael Chi-Wang,Peng, Shie-Ming,Cheung, Kung-Kai,Che, Chi-Ming
-
-
Read Online
- Highly practical sodium(i)/azobenzene catalyst system for aerobic oxidation of benzylic alcohols
-
An economic, environmental and practical aerobic oxidation of benzylic alcohols and hetero aryl alcohols to the corresponding carbonyl compounds with good substrate scope is disclosed for the first time. Good to excellent yields were obtained by employing economic and commercially available sodium bromide and a catalytic amount of azobenzene under metal-free and ligand-free conditions. Moreover, aldehydes and acids, the oxidation products of benzylic 1° alcohols, could be obtained using sodium bromide and sodium hydroxide as the co-catalyst respectively in high yields.
- Liu, Chengkou,Fang, Zheng,Yang, Zhao,Li, Qingwen,Guo, Shiyu,Guo, Kai
-
-
Read Online
- Selective oxidation of primary and secondary alcohols with chromium trioxide in ionic liquid
-
The oxidation of primary and secondary alcohols to corresponding aldehydes and ketones by CrO3 in room temperature ionic liquids is an efficient and low flammability method with fast rate, facile procedure and high yields.
- Zheng, Yun-Fa,Du, Xing-Fen,Bao, Wei-Liang
-
-
Read Online
- Tsuji-Wacker Oxidation of Terminal Olefins using a Palladium-Carbon Nanotube Nanohybrid
-
Palladium nanoparticles supported on carbon nanotubes were used in the Tsuji-Wacker oxidation. The palladium-based nanohybrid was found to be very active in combination with cuprous chloride for the selective oxidation of terminal olefins into methyl ketones. The co-catalytic system operates under very mild and sustainable conditions (room temperature, atmospheric pressure, low catalyst loading), as opposed to previously reported catalysts, and can be recycled without any loss in activity. Give it a whack: Palladium nanoparticles supported on carbon nanotubes are used in combination with cuprous chloride for the selective Tsuji-Wacker oxidation of terminal olefins into methyl ketones. The co-catalytic system operates under very mild and sustainable conditions and can be recycled without any loss in activity.
- Donck, Simon,Gravel, Edmond,Shah, Nimesh,Jawale, Dhanaji V.,Doris, Eric,Namboothiri, Irishi N. N.
-
-
Read Online
- Transition-Metal-Free: A Highly Efficient Catalytic Aerobic Alcohol Oxidation Process
-
A highly efficient catalytic system without transition metals has been developed for aerobic alcohol oxidations. Under the optimal reaction conditions, various alcohol substrates were converted into their corresponding carbonyl compounds by air with TEMPO/Br2/NaNO2 as catalyst, especially the oxidation of benzylic alcohols to benzaldehydes in high yields. Copyright
- Liu, Renhua,Liang, Xinmiao,Dong, Chunyan,Hu, Xinquan
-
-
Read Online
- Reactions of OH and SO4.- with Some Halobenzenes and Halotoluenes: A Radiation Chemical Study
-
The optical absorption and kinetic characteristics of the transients formed in the reactions of OH and SO4.- with bromobenzene, ortho and meta-isomers of chloro- and bromobenzenes, and monobromotoluenes have been studied by pulse radiolysis technique.The rates for OH reaction are generally higher (k = (1.7-4.4)X109 M-1s-1) than those found for the SO4.- reaction (k = (0.4-2.3)x109 M-1s-1). ρ+ values of -0.4 for OH and -1.2 for SO4.- reactions were obtained from the Hammett analysis.The formation of substituted hydroxycyclohexadienyl radicals (λmax = 315-330 nm) is the major reaction channel, and the phenoxyl type radical (λ >/=400 nm) formation is an additional minor process in the SO4.- reaction.Abstraction of H by SO4.- from the -CH3 group is only significant with the para-isomers of bromo- and chlorotoluenes.This result is in accord with the observed yields (70 percent of SO4.-) of the products resulting from the oxidation of the 4-chlorobenzyl radical in the presence of K3Fe(CN)6 under steady-state conditions.The total yields of the phenolic products accounting for >90 percent of OH and SO4.- suggest that the attack at the ipso positions is considerably small.The rate constants for OH reactions relative to benzene at positions 3 and 6 of 2-chlorotoluene and positions 2 and 3 of 4-chlorotoluene are between 1.18 and 1.39, indicating that the directing effects of -CH3 and -Cl groups are comparable.This is also reflected in the additive effects of activation of the ortho and para-positions and deactivation of meta-positions by these substituents in 3-chlorotoluene.
- Merga, Getahun,Rao, B. S. M.,Mohan, H.,Mittal, J. P.
-
-
Read Online
- Oxidative transformations of p-chloro- and p-fluorostyrene epoxides in the presence of p-toluenesulfonic acid
-
Mild oxidation of two halogenated styrene epoxides, 2-(4-chlorophenyl) oxirane (CSE) and 2-(4-fluorophenyl)oxirane (FSE), was studied in the presence of p-toluenesulfonic acid (TSA). Hydrogen peroxide and p-chlorobenzaldehyde are the products of CSE oxidation. The kinetics of the overall CSE consumption and oxidation of CSE and FSE are identical to those revealed earlier for the oxidation of styrene epoxide (SE). The consumption and oxidation rates do not depend on the epoxide concentration (zero order) and are proportional to the TSA concentration. At 343 K, the oxidation rate of CSE and FSE are higher than that for SE by factors of 2 and 7, respectively. The introduction of the halogen atoms in the p-position on the phenyl ring accelerates the oxidation.
- Petrov,Solyanikov
-
-
Read Online
- Oxidation of benzylic alcohols with butyltriphenylphosphonium permanganate under non-aqueous conditions
-
Oxidation of benzylic alcohols with butyltriphenylphosphonium permanganate (BuPh3P+MnO4-) 1 (BTPPPM) in acetonitrile at room temperature is reported. This reagent selectively oxidizes benzylic alcohols in the presence of other oxidizable functional groups.
- Hajipour, Abdol Reza,Mallakpour, Shadpour E.,Samimi, Heshmat A.
-
-
Read Online
- Role of vanadium and pyridine in heteropolycompounds for selective oxidation of alcohols with hydrogen peroxide
-
This study describes the application of heteropolyacids H3PMo12O40,H4SiMo12O40, H4PMo11VO40, H5PMo10V2O40, H9PMo6V6O40, and a hybrid pyridine-modified heteropolyacid with Keggin structure for selective oxidation of alcohols to ketones or aldehydes using aqueous hydrogen peroxide and acetonitrile as solvent. Performance of these different catalysts in 1-phenylethanol oxidation was studied. Influence of reaction temperature, amount of catalyst and hydrogen peroxide and reaction time on the yield of acetophenone was investigated to obtain optimal reaction conditions. Oxidation ability of the catalyst depended on the number of vanadium atoms present in the Keggin ion and to a lesser extent on pyridine substitution in the Keggin secondary structure. In order to explore the applicability of the method for selective oxidation of alcohols to ketones or aldehydes, various alcohols were investigated according to the general procedure using hybrid pyridine-modified heteropolyacid. Indian Academy of Sciences.
- Palermo, Valeria,Villabrille, Paula I.,Vazquez, Patricia G.,Caceres, Carmen V,Tundo, Pietro,Romanelli, Gustavo P.
-
-
Read Online
- Magnetic crosslinked copoly(ionic liquid) nanohydrogel supported palladium nanoparticles as efficient catalysts for the selective aerobic oxidation of alcohols
-
Nowadays it is still a great sustainable processes challenge to produce efficient, selective and easy magnetic recovery and recycling catalysts for oxidation of alcohols using air as the oxidant. In this work, a new magnetic nanohydrogel comprising [DABCO-allyl][Br] ionic liquid, allyl alcohol and N,N’-methylenebis(acrylamide) is used for stabilization of small and highly uniform palladium nanoparticles of 3–4 nm size MXCPILNHG@Pd. This material has been characterized by Fourier-transform infrared spectroscopy (FTIR), atomic adsorption spectroscopy (AAS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM-Map, energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectra (XPS), vibrating-sample magnetometer (VSM) and dynamic light scattering (DLS). According to optimization of cross-linking degree and ratio of DABCO-IL, MXCPILNHG-2@Pd is found as a highly selective catalyst in oxidations of primary alcohols to the corresponding aldehydes in toluene and to acids in water. Furthermore, secondary alcohols were reacted efficiently to the corresponding ketones in both toluene and water. Catalyst is magnetically recovered and recycled for several times in both toluene and water and the reused catalysts are characterized by TEM and XPS.
- Gholinejad, Mohammad,Afrasi, Mahmoud,Nikfarjam, Nasser,Nájera, Carmen
-
-
Read Online
- Mild and efficient oxidation of alcohols with sodium periodate catalyzed by polystyrene-bound Mn(III)porphyrin
-
Mild and efficient oxidation of primary and secondary alcohols with sodium periodate catalyzed by Mn(TPyP), [manganese(III)tetra(4-pyridyl)porphyrin], supported on chloromethylated polystyrene, [Mn(TPyP)-CMP], at room temperature were reported. This catalyst can be reused consecutively four times in the oxidation of 4-chlorobenzyl alcohol in 97% yield without significant loss of its activity.
- Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj,Kargar, Hadi
-
-
Read Online
- Symmetric quaternary phosphonium cation and perchlorate/chlorate anions: Crystal structure, Database study and Hirshfeld surface analysis
-
Two new quaternary phosphonium salts of 1,2-ethandiylbis (triphenylphosphonium) Diperchlorate (I), 1,2-ethandiylbis (triphenylphosphonium) Dichlorate (II) were prepared and used for oxidation of different benzylic alcohols to afford their corresponding ca
- Salmasi,Salimi,Gholizadeh,Rahmani,Garrison
-
-
Read Online
- Oxidation of benzylic alcohols to their corresponding carbonyl compounds using KIO4 in ionic liquid by microwave irradiation
-
A chemoselective, straightforward, and rapid method for oxidation of alcohols to the corresponding carbonyl compounds using microwave irradiation and a catalytic amount of ionic liquid is reported. The reaction has been carried out with excellent yields and short reaction times. Copyright Taylor & Francis Group, LLC.
- Hajipour, Abdol Reza,Rafiee, Fatemeh,Ruoho, Arnold E.
-
-
Read Online
- SBA-15 Supported 1-Methyl-2-azaadamanane N-Oxyl (1-Me-AZADO) as Recyclable Catalyst for Oxidation of Alcohol
-
Herein, we designed and synthesized an SBA-15 supported 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO) and investigated its catalytic performance for selective oxidation of alcohols under Anelli's conditions. The first example of immobilization of 1-Me-AZADO was very important to advance the oxgenation effectively because this supported N-oxyl has excellent catalytic activity for oxidation of alcohols to carbonyl compounds, and more importantly, it can be conveniently recovered and reused at least 6 times without significant effect on its catalytic efficiency.
- Tian, Yangwu,Guo, Xiaqun,Li, Meichao,Li, Chunmei,Hu, Xinquan,Jin, Liqun,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu
-
-
Read Online
- Photochemical oxidative deprotection of 1,3-dithianes to carbonyl compounds with hydrogen peroxide (HP)
-
Regeneration of carbonyl compounds from their 1,3-dithianes were achieved using photochemical oxidation with (HP 30%) in relatively high yields. Thus, an efficient, economic and simple photochemical method for this deprotection has been demonstrated.
- Habibi,Tangestaninejad,Mohammadpoor-Baltork,Montazerozohori
-
-
Read Online
- Mannich base Cu(II) complexes as biomimetic oxidative catalyst
-
Galactose Oxidase (GOase) and catechol oxidase (COase) are the metalloenzymes of copper having monomeric and dimeric sites of coordination, respectively. This paper summarizes the results of our studies on the structural, spectral and catalytic properties of new mononuclear copper (II) complexes [CuL(OAc)] (1), and [CuL2] (2), (HL = 2,4?dichloro?6?{[(2′?dimethyl?aminoethyl)methylamino]methyl}?phenol) which can mimic the functionalities of the metalloenzymes GOase and COase. The structure of the compounds has been elucidated by X-ray crystallography and the mimicked Cu(II) catalysts were further characterized by EPR. These mimicked models were used for GOase and COase catalysis. The GOase catalytic results were identified by GC–MS and, analyzed by HPLC at room temperature. The conversion of benzyl alcohol to benzaldehyde were significant in presence of a strong base, Bu4NOMe in comparison to the neutral medium. Apart from that, despite of being monomeric in nature, both the homogeneous catalysts are very prone to participate in COase mimicking oxidation reaction. Nevertheless, during COase catalysis, complex 1 was found to convert 3,5?ditertarybutyl catechol (3,5-DTBC) to 3,5?ditertarybutyl quinone (3,5-DTBQ) having greater rate constant, kcat or turn over number (TON) value over complex 2. The generation of reactive intermediates during COase catalysis were accounted by electrospray ionization mass spectrometry (ESI-MS). Through mechanistic approach, we found that H2O2 is the byproduct for both the GOase and COase catalysis, thus, confirming the generation of reactive oxygen species during catalysis. Notably, complex 1 having mono-ligand coordinating atmosphere has superior catalytic activity for both cases in comparison to complex 2, that is having di-ligand environment.
- Kundu, Bidyut Kumar,Ranjan, Rishi,Mukherjee, Attreyee,Mobin, Shaikh M.,Mukhopadhyay, Suman
-
-
Read Online
- A new layered metal-organic framework as a promising heterogeneous catalyst for olefin epoxidation reactions
-
A new layered MOF material [Co(Hoba)2·2H2O] (1) (H2oba = 4,4′-oxybis(benzoic acid)) has been synthesized and used as a highly recyclable heterogeneous catalyst for olefin epoxidation reactions. Both high conversion (96%) and high selectivity of epoxide products (96%) are achieved.
- Zhang, Jingming,Biradar, Ankush V.,Pramanik, Sanhita,Emge, Thomas J.,Asefa, Tewodros,Li, Jing
-
-
Read Online
- Solid state desemicarbazonation on clayfen under microwave irradiation
-
A new, efficient, and environmentally benign method for the cleavage of semicarbazones has been achieved by a simple reaction of semicarbazones with clayfen under microwave irradiation.
- Heravi,Ajami,Mohajerani,Tajbakhsh,Ghassemzadeh,Tabar-Hydar
-
-
Read Online
- A CONVENIENT SYNTHESIS OF EPOXIDES FROM OLEFINS USING MOLECULAR OXYGEN IN THE ABSENCE OF METAL CATALYSTS
-
The system consisting of molecular oxygen and aldehydes (e.g., isobutyraldehyde and pivalaldehyde) oxidizes various olefins to give epoxides in high yields at 40 deg C for 3-6 h.Key Words: Epoxidation, Olefin, Molecular oxygen, Aldehyde
- Kaneda, Kiyotomi,Haruna, Shigeru,Imanaka, Toshinobu,Hamamoto, Masatoshi,Nishiyama, Yutaka,Ishii, Yasutaka
-
-
Read Online
- A mild titanium-based system for the reduction of amides to aldehydes
-
A mild method for the reduction of amides to aldehydes using 1,1,3,3-tetramethyldisiloxane/titanium(IV) isopropoxide reducing system is described. The reaction occurs under mild conditions and allows the reduction of aromatic as well as aliphatic, tertiary amides to the corresponding aldehydes, in good yields. This methodology was extended to the reduction of aromatic secondary and primary amides to the corresponding aldehydes.
- Laval, Stéphane,Dayoub, Wissam,Favre-Reguillon, Alain,Demonchaux, Patrice,Mignani, Gérard,Lemaire, Marc
-
-
Read Online
- Mixed Monosilyl Acetals and Catalyst-Dependent Chemoselective Mukaiyama Aldol Reactions
-
We report a direct, simple, and straightforward approach for the construction of a mixed monosilyl acetal as a new and synthetically valuable functional group by mixing an aldehyde, sodium tert-butoxide, and trimethylsilyl azide. We also demonstrate a catalyst-dependent chemoselective reaction between mixed monosilyl acetals and silyl ketene acetals through Mukaiyama aldol reactions to give different structures of O-protected β-hydroxy esters in excellent yields with high chemoselectivities. This study provided the existence of an oxonium ion intermediate and of its kinetically controlled reaction with the pre-equilibrated silyl enol ether obtained from (E)- and (Z)-isomerization.
- Kim, Sun Min,Yang, Hye Sung,Eum, Heesung,Ha, Hyun-Joon,Yang, Jung Woon
-
-
Read Online
- NaNO2-activated, iron-TEMPO catalyst system for aerobic alcohol oxidation under mild conditions
-
FeCl3-TEMPO-NaNO2 catalyses the selective and mild aerobic oxidation of a broad range of alcohols to the corresponding aldehydes and ketones. The Royal Society of Chemistry 2005.
- Wang, Naiwei,Liu, Renhua,Chen, Jiping,Liang, Xinmiao
-
-
Read Online
- Design and synthesis of hybrid solids based on the tetravanadate core toward improved catalytic properties
-
Five inorganic-organic hybrid vanadates based on tetravanadate cores, transition metals and N-donor ligands have been designed and synthesized under hydrothermal conditions, namely, [Zn(eIM)3]2V4O12 (1), [Zn(pIM)3]2V4O12·H2O (2), [Zn(ipIM)3]2V4O12 (3), [Co(eIM)3]2V4O12·H2O (4), [Cu(eIM)2(H2O)]2V4O12 (5) (eIM = 1-ethylimidazole, pIM = 1-propylimidazole, ipIM = isopropylimidazole). All compounds were fully characterized by single-crystal XRD, powder XRD, elemental analysis, TGA, and FT-IR spectroscopy. The hybrid zinc vanadates (1-3) and cobalt vanadate (4) exhibit interesting 2D folded structures and the hybrid copper vanadate (5) presents a 1D chain configuration. All compounds can catalyze olefin epoxidation reactions when using TBHP (TBHP = tert-butyl hydroperoxide) as an oxidant in acetonitrile. The introduction of transition metal ions into tetravanadate cores not only improved the catalytic activity but also fulfilled the heterogeneous catalytic behavior. 1-5 all exhibit extraordinary efficiency in converting olefins to the corresponding epoxides with high conversion and selectivity (particularly, conv. up to 97.1%, sele. up to 100% for 1). Leaching test was also carried out to prove the heterogeneous behavior.
- Niu, Yan-Hong,Yang, Song,Li, Ji-Kun,Xu, Yan-Qing,Hu, Chang-Wen
-
-
Read Online
- Highly efficient and metal-free oxidation of olefins by molecular oxygen under mild conditions
-
Highly efficient and metal-free aerobic oxidations of cyclohexene and styrene were successfully performed under mild conditions in the presence of 1,4-diamino-2,3-dichloro-anthraquinone and N-hydroxyphthalimide. When cyclohexene was oxidized, an 89% conversion and 71% selectivity for 2-cyclohexen-1-one was obtained under 0.3 MPa at 80 °C for 5 h. In the oxidation of styrene, a 77% conversion and 69% selectivity for benzaldehyde was obtained for 10 h. Furthermore, more olefins were efficiently oxidized to corresponding oxygenated products under mild conditions. All kinds of factors that affected cyclohexene oxidation were well investigated, and the possible reaction mechanism was provided.
- Tong, Xinli,Xu, Jie,Miao, Hong,Yang, Guanyu,Ma, Hong,Zhang, Qiaohong
-
-
Read Online
- Poly(9,9′-spirobifluorene-manganese porphyrin): A new catalytic material for oxidation of alkenes by iodobenzene diacetate and iodosylbenzene
-
Anodic oxidation of tetraspirobifluorene-manganese porphyrin lead to the coating of the working electrode by insoluble electroactive poly(9,9′-spirobifluorene-manganese porphyrin) films for which electrochemical behaviour and physicochemical properties are described; these polymeric materials are able to catalyze the heterogeneous epoxidation of styrene with iodobenzene diacetate and iodosylbenzene.
- Poriel, Cyril,Ferrand, Yann,Le Maux, Paul,Raul-Berthelot, Joelle,Simonneaux, Gerard
-
-
Read Online
- Synthesis, characterization and catalytic activity of oleic acid-coated TiO2 nanoparticles carrying MoO2 (acac)2 in the oxidation of olefins and sulfides using economical peroxides
-
Titanium oxide nanoparticles were synthesized by a modified polymerized complex derived sol-gel method followed by coating with oleic acid (OA) to modify their surface. The reaction with MoO2 (acac)2 yielded the TiO2-OA-MoO2 nanocomposite as a supported cis-dioxomolybdenum complex. The structural and morphological characterization of the as-prepared TiO2 and TiO2-OA-MoO2 were carried out by different techniques such as XRD, FT-IR, TGA and TEM. The catalytic activity of the TiO2-OA-MoO2 nanocomplex in the epoxidation of olefins and oxidation of sulfides to sulfoxides using H 2O2 in ethanol as a safe solvent was investigated. The reactions also proceeded efficiently in the presence of tert-butylhydroperoxide (TBHP). Good/high yields and excellent selectivity were obtained. The recovery of the title heterogeneous nanocatalyst was easy and efficient and its catalytic activity was strikingly different from other nanooxometals such as m-ZrO 2, MoO3, Fe3O4 and TiO2, as well as their nanocomposites such as TiO2-OA, ZrO 2-OA-MoO2, MoO3-OA-MoO2 and Fe 3O4-OA-MoO2. the Partner Organisations 2014.
- Jafarpour, Maasoumeh,Ghahramaninezhad, Mahboube,Rezaeifard, Abdolreza
-
-
Read Online
- Crystal structure and solid state computational (DFT/Hirshfeld surface) study for probing a new efficient and recyclable oxidation reagent, 1,2-ethandiylbis(triphenylphosphonium) peroxodisulfate dihydrate
-
A new, efficient and recyclable reagent, 1,2-Ethandiylbis(triphenylphosphonium) peroxodisulfate dihydrate, for the oxidation of benzylic alcohols has been synthesized and characterized by IR, NMR spectroscopy, and single crystal X-ray crystallography. Usi
- Salmasi,Salimi,Gholizadeh,Abolghasempour,Garrison, Jered C.
-
-
Read Online
- Solid state deprotection of acetals and thioacetals using benzyltriphenylphosphonium peroxymonosulfate
-
A variety of acetals and thioacetals 2 are deprotected to the corresponding parent carbonyl compounds 3 under solvent-free conditions using benzyltriphenyl-phosphonium peroxymonosulfate (1) in the presence of aluminum chloride.
- Hajipour, Abdol Reza,Mallakpour, Shadpour E.,Mohammadpoor-Baltork, Iraj,Adibi, Hadi
-
-
Read Online
- Halogen/lithium exchange in hydrocarbon media; Basic and continuous reactor studies
-
The halogen/lithium (X/Li) exchange's usefulness is challenged by the extreme conditions employed during the conversion of a bromo or an iodo substituent to an organolithium intermediate. Our preliminary disclosure reveals that simple X/Li exchanges can be accomplished at ambient temperature and in doped hydrocarbon media using n-BuLi. Use of a continuous reactor featuring brief reaction times (≤1 s) and large product throughputs further facilitates the production of a product resulting from a sequential X/Li exchange and nucleophilic addition.
- Slocum,Kusmic, Damir,Raber, Jeffrey C.,Reinscheld, Thomas K.,Whitley, Paul E.
-
-
Read Online
- Selective oxidation of oximes to carbonyl compounds using N-bromo-N-benzoyl-4-toluenesulfonamide
-
Oximes were converted to parent carbonyl compounds in good yields by treating with N-bromo-N-benzoyl-4-toluenesulfonamide.
- Khazaei, Ardeshir,Manesh, Abbas Amini
-
-
Read Online
- Cu(II) Schiff base complex supported on Fe3O4 nanoparticles as an efficient nanocatalyst for the selective aerobic oxidation of alcohols
-
Herein, we have prepared a new Cu(II) Schiff base complex supported onto the surface of modified Fe3O4 nanoparticles as highly stable, heterogeneous and magnetically recyclable nanocatalyst for the selective aerobic oxidation of different alcohols. The structure, morphology, chemical composition and magnetic property of the nanocatalyst and its precursors were characterized using FT-IR, TGA, AAS, ICP-AES, XRD, SEM, EDS, VSM and N2 adsorption–desorption analyses. Characterization results exhibited the uniform spherical morphology for nanocatalyst and its precursors. A promising eco-friendly method with short reaction time and high conversion and selectivity for oxidation of various primary and secondary alcohols under O2 atmosphere condition was achieved. The synthesized nanocatalyst could be recovered easily by applying an external magnetic field and reused for least eight subsequent reaction cycles with only negligible deterioration in catalytic performance.
- Aghajani, Milad,Monadi, Niaz
-
-
Read Online
- Selective oxidation of p-chlorotoluene to p-chlorobenzaldehyde over metal-modified OMS-2 molecular sieves
-
A series of manganese oxide octahedral molecular sieve (OMS-2) doped with Co, V, and Ce (Me) with molar ratio Me/Mn?=?0.04 and 0.12 were prepared via a one-step reflux method, and were characterized by XRD, SEM, IR, BET, ICP, XPS, and TG techniques. The OMS-2 materials doped with Me having Me/Mn?=?x are denoted as Me-M(x). It was found that Ce mainly enters the tunnel structure of OMS-2 instead of K, Co mainly substitutes for Mn in the framework, and V is likely to substitution into both the Mn and K in the cryptomelane tunnel structure. The length of OMS-2 rods decreases with the decline of K+ mole fraction in the OMS-2 tunnels. Doping V and Ce markedly decreases the crystallization of OMS-2. Ce-M(0.12) shows a specific surface area (142?m2?g?1) roughly double that of OMS-2 (69?m2?g?1). All the Me-M(x) materials were tested as catalysts for the oxidation of p-chlorotoluene to p-chlorobenzaldehyde with molecular oxygen, and it is Ce-M(0.12) that shows the highest catalytic activity. The excellent performance is attributed to the large specific surface area and good mobility of oxygen species of the Ce-M(0.12) material.
- Xie, Jun,Chen, Lang,Zhou, Wei-Fang,Au, Chak-Tong,Yin, Shuang-Feng
-
-
Read Online
- Direct aza-Diels-Alder reaction in water catalyzed by layered α-zirconium hydrogen phosphate and sodium dodecyl sulfate
-
The direct aza-Diels-Alder reaction between 2-cyclohexen-1-one (1) and benzaldimines 2 in water is reported for the first time. The reaction occurs at 30°C, is catalyzed by layered α-zirconium hydrogen phosphate (α-ZrP) and requires the presence of sodium dodecyl sulfate (SDS). The reaction yield is excellent, the reaction is faster and the exo diastereo-selectivity is higher than when organic solvent is used. The one-pot, three-component version of the reaction and the recycling of both the catalyst and the aqueous mother liquor in toto (water, α-ZrP and SDS) have also been investigated. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
- Costantino, Umberto,Fringuelli, Francesco,Orru, Mara,Nocchetti, Morena,Piermatti, Oriana,Pizzo, Ferdinando
-
-
Read Online
- Manganese(III) porphyrin supported on multi-wall carbon nanotubes: A highly efficient and reusable biomimetic catalyst for oxidative decarboxylation of α-arylcarboxylic acids and oxidation of alkanes with sodium periodate
-
In the present work, the highly efficient oxidative decarboxylation of carboxylic acids and also the oxidation of alkanes with sodium periodate catalyzed by tetrakis(p-aminophenyl)porphyrinatomanganese(III) chloride, [Mn(TNH2PP)Cl], supported on functionalized multi-wall carbon nanotubes, MWCNT, is reported. The catalyst, [Mn(TNH2PP)Cl@MWCNT], was used as an efficient and heterogeneous catalyst for hydroxylation of alkenes with NaIO4 at room temperature, in the presence of imidazole as an axial ligand. Also, in this system, carboxylic acids were converted to their corresponding carbonyl compounds. This heterogenized catalyst could be reused several times without significant loss of its catalytic activity.
- Araghi, Mehdi,Bokaei, Forough
-
-
Read Online
- Functionalized-1,3,4-oxadiazole ligands for the ruthenium-catalyzed Lemieux-Johnson type oxidation of olefins and alkynes in water
-
Three arene-ruthenium(II) complexes bearing alkyloxy(5-phenyl-1,3,4-oxadiazol-2-ylamino)(4-trifluoromethylphenyl)methyl ligands were quantitatively obtained through the reaction of (E)-1-(4-trifluoromethylphenyl)-N-(5-phenyl-1,3,4-oxadiazol-2-yl)-methanimine with the ruthenium precursor [RuCl2(η6-p-cymene)]2 in a mixture of the corresponding alcohol and CH2Cl2 at 50 °C. The obtained complexes were fully characterized by elemental analysis, infrared, NMR and mass spectrometry. Solid-state structures confirmed the coordination of the 1,3,4-oxadiazole moiety to the ruthenium center via their electronically enriched nitrogen atom at position 3 in the aromatic ring. These complexes were evaluated as precatalysts in the Lemieux-Johnson type oxidative cleavage of olefins and alkynes in water at room temperature with NaIO4 as oxidizing agent. Good to full conversions of olefins into the corresponding aldehydes were measured, but low catalytic activity was observed in the case of alkynes. In order to get more insight into the mechanism, three analogue arene-ruthenium complexes were synthesized and tested in the oxidative cleavage of styrene. The latter tests clearly demonstrated the importance of the hemilabile alkyloxy groups, which may form more stable (N,O)-chelate intermediates and increase the efficiency of the cis-dioxo-ruthenium(VI) catalyst.
- Hkiri, Shaima,Touil, Soufiane,Samarat, Ali,Sémeril, David
-
-
- Highly atom efficient synthesis of 2,2,4,5-tetrasubstituted 3(2H)-furanones having both hydroxyl and amino substituents
-
We have developed a highly atom efficient synthesis of tetrasubstituted 3(2H)-furanones from easily accessible starting materials such as C,N-diarylaldonitrones and dibenzoylacetylene. Control experiments revealed that reaction of aldonitrones having electron-withdrawing groups on the C-aryl substituent in polar aprotic solvents exhibited high product selectivity while reaction temperature has only a negligible effect on product yield and selectivity.
- Antony, Jesna,Mathai, Sindhu,Natarajan, Rakesh,P. Musthafa, Sumi,Rappai, John P.,S. Devaky, Karakkattu
-
supporting information
(2022/02/25)
-
- Controlled reduction of activated primary and secondary amides into aldehydes with diisobutylaluminum hydride
-
A practical method is disclosed for the reduction of activated primary and secondary amides into aldehydes using diisobutylaluminum hydride (DIBAL-H) in toluene. A wide range of aryl and alkyl N-Boc, N,N-diBoc and N-tosyl amides were converted into the corresponding aldehydes in good to excellent yields. Reduction susceptible functional groups such as nitro, cyano, alkene and alkyne groups were found to be stable. Broad substrate scope, functional group compatibility and quick conversions are the salient features of this methodology.
- Azeez, Sadaf,Kandasamy, Jeyakumar,Sabiah, Shahulhameed,Sureshbabu, Popuri
-
supporting information
p. 2048 - 2053
(2022/03/31)
-
- The: In situ fabrication of ZIF-67 on titania-coated magnetic nanoparticles: A new platform for the immobilization of Pd(ii) with enhanced catalytic activity for organic transformations
-
Considering the outstanding characteristics of metal organic frameworks (MOFs) and magnetic nanoparticles, herein we report a facile approach for the synthesis of a magnetic zeolitic-imidazolate-framework-supported palladium(ii) catalyst. In brief, zeolitic imidazolate framework-67 (ZIF-67) was successfully incorporated onto the surface of titania-coated magnetic nanoparticles using ethane-1,2-diamine as a linker, and then Pd(ii) was immobilized onto this. The resulting Pd@ZIF-67-Fe3O4-TiO2 catalyst possesses a high surface area (205 m2 g-1), a large pore volume (0.10 cm3 g-1), good magnetic responsivity (10.71 emu g-1), and high stability. A comparative analysis of Pd@ZIF-67-Fe3O4-TiO2 and Pd@Fe3O4-TiO2 catalysts for the oxidation, reduction, and oxidative deprotection of oximes was done to investigate the effects of ZIF-67 on the catalytic performance of Pd species. Substantial differences in activity and stability were observed in the presence of ZIF-67, suggesting that ZIF-67 plays an important role in enhancing the activity of Pd(ii). This superior catalytic activity and stability arises due to a synergistic effect between well-dispersed palladium species and highly porous ZIF-67, which was confirmed via XPS analysis. Moreover, the catalyst retains its structure, chemical environment, and good magnetic response even after five catalytic runs, as confirmed via FTIR, XRD, XPS, and VSM studies of reused catalyst samples.
- Kaur, Manpreet,Paul, Satya,Sharma, Chandan,Sharma, Sukanya
-
p. 20309 - 20322
(2021/11/22)
-
- Ferric ion concentration-controlled aerobic photo-oxidation of benzylic C–H bond with high selectivity and conversion
-
A Fe(III)-promoted highly selective photo-oxidation of benzylic C–H bond delivering relative carbonyl products is reported. By altering the concentration of ferric salt, methylarenes can be selectively oxidized under UV irradiation to furnish aromatic aldehydes or acids, respectively. By this protocol, the oxidation of ethylarenes provides the corresponding acetophenones. The reaction is inferred to involve divergent pathways in different concentrations of catalyst for the alternative selectivity between aldehydes and aicds. The reusable catalyst, high conversion and selectivity make this oxidation a green and economic protocol for the synthesis of aromatic carbonyl compounds.
- Bu, Hongzhong,Gu, Jiefan,Li, Yufeng,Ma, Hongfei,Wan, Yuting,Wu, Zheng-Guang,Zhang, Weijian,Zhou, Ying'ao,Zhu, Hongjun
-
-
- Selective Electrochemical Oxygenation of Alkylarenes to Carbonyls
-
An efficient electrochemical method for benzylic C(sp3)-H bond oxidation has been developed. A variety of methylarenes, methylheteroarenes, and benzylic (hetero)methylenes could be converted into the desired aryl aldehydes and aryl ketones in moderate to excellent yields in an undivided cell, using O2 as the oxygen source and lutidinium perchlorate as an electrolyte. On the basis of cyclic voltammetry studies, 18O labeling experiments, and radical trapping experiments, a possible single-electron transfer mechanism has been proposed for the electrooxidation reaction.
- Li, Xue,Bai, Fang,Liu, Chaogan,Ma, Xiaowei,Gu, Chengzhi,Dai, Bin
-
supporting information
p. 7445 - 7449
(2021/10/02)
-
- SBA-15 Supported Silver Catalyst for the Efficient Aerobic Oxidation of Toluene Under Solvent-Free Conditions
-
The efficient SBA-15 supported silver catalysts(Ag/SBA-15) were prepared and characterized by ICP-OES, XRD, TEM, SEM, XPS and N2 adsorption–desorption techniques. The catalysts exhibited an excellent catalytic activity for the aerobic oxidation of toluene to benzaldehyde under solvent-free conditions. Conversion of toluene and selectivity of benzaldehyde were 50% and 89% respectively over catalyst with 9.1 wt% Ag loading (10Ag/SBA-15). A wide range of substrates were tolerated under the selected reaction conditions. The kinetic study shows that the oxidation of toluene over 10Ag/SBA-15 is pseudo-first-order reaction and the activation energy Ea is 45.1?kJ/mol. A plausible mechanism involving oxygen free radicals was proposed for the aerobic oxidation reaction. Compared with the traditional method, the newly designed heterogeneous catalytic system shows better economic applicability, environmental friendliness and broader application prospects. Graphical abstract: [Figure not available: see fulltext.]
- Chen, Lei,Chen, Yanjiao,Dai, Xuan,Guo, Jiaming,Peng, Xinhua
-
-
- Metal- And additive-free C-H oxygenation of alkylarenes by visible-light photoredox catalysis
-
A metal- and additive-free methodology for the highly selective, photocatalyzed C-H oxygenation of alkylarenes under air to the corresponding carbonyls is presented. The process is catalyzed by an imide-acridinium that forms an extremely strong photooxidant upon visible light irradiation, which is able to activate inert alkylarenes such as toluene. Hence, this is an easy to perform, sustainable and environmentally friendly oxidation that provides valuable carbonyls from abundant, readily available compounds.
- García Manche?o, Olga,Kuhlmann, Jan H.,Pérez-Aguilar, María Carmen,Piekarski, Dariusz G.,Uygur, Mustafa
-
supporting information
p. 3392 - 3399
(2021/05/21)
-
- Photo-tunable oxidation of toluene and its derivatives catalyzed by TBATB
-
In this report, tetrabutylammonium tribromide (TBATB) was introduced as an efficient visible light active catalyst to carry out the aerobic oxidation of toluene, its derivatives, and some of methyl arenes to benzaldehydes, benzoic acids and ketones in good to high yields. All the oxidation reactions were performed under mild conditions using oxygen as a green oxidant, a catalytic amount of TBATB under blue (460 nm), royal blue (430 nm), and violet LED (400 nm) irradiation. It was found that the reactions selectivity was significantly affected by changing the solvent (from CH3CN to EtOAc) and LED wavelength (from blue to violet). In the following, our mechanistic studies revealed that the visible light oxidation of toluenes and methyl arenes over TBATB could be following a benzyl peroxy radical intermediate.
- Mardani, Atefeh,Kazemi, Foad,Kaboudin, Babak
-
-
- Core-shell Co-MOF-74@Mn-MOF-74 catalysts with Controllable shell thickness and their enhanced catalytic activity for toluene oxidation
-
A series of core-shell Co-MOF-74@Mn-MOF-74 samples with different shell thicknesses were prepared by the seed growth method, which were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), inductively coupled plasma mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy, nitrogen adsorption-desorption and scanning electron microscopy (SEM). The shell thickness of these MOF samples were successfully controlled by adjusting the mass ratio between MnCl2·4H2O and Co-MOF-74. On this basis, these MOFs were applied to the catalytic oxidation of toluene. The results showed that with the growth of Mn-MOF-74 in the outer layer of Co-MOF-74, the oxidative selectivity of the substrate to benzaldehyde was greatly improved for the synergy between the core layer and shell layer. The conversion of toluene was 22.4%, and the selectivity of benzaldehyde was 98.1%. In addition, the catalyst can transform various substituted toluene into the corresponding aldehydes in highly selectivity and still keep good stability after four catalytic cycles. The selectivity of the corresponding aldehyde is generally above 80%.
- Gu, Xiangyu,Huang, Cheng,Xu, Zengchuang,Wu, Hao,Dong, Ruilan,Liu, Rui,Chen, Jing,Zhu, Hongjun
-
-
- Oxidation/ MCR domino protocol for direct transformation of methyl benzene, alcohol, and nitro compounds to the corresponding tetrazole using a three-functional redox catalytic system bearing TEMPO/Co(III)-porphyrin/ Ni(II) complex
-
A redox catalytic system for oxidation-reduction reactions and the domino preparation of tetrazole compounds from nitro and alcohol precursors was designed, prepared and characterized by UV–vis, GPC, TGA, XRD, EDX, XPS, VSM, FE-SEM, TEM, DLS, BET, NMR, and ICP analyses. The catalyst was prepared via several successive steps by demetalation of chlorophyll b, copolymerization with acrylated TEMPO monomers, complexation with Ni and Co metals (In two different steps), then immobilized on magnetic nanoparticles. The presence of three functional groups including TEMPO, coordinated cobalt, and coordinated nickel in the catalyst, allowed the oxidation of various types of alcohols, alkyl benzenes as well as the reduction of nitro compounds by a single catalyst. All reactions yielded up to 97 % selectivity for oxidation and reduction reactions. Next, the ability of the catalyst to successfully convert alcohol, methyl benzenes and nitro to their corresponding tetrazoles was studied.
- Mahmoudi, Boshra,Rostami, Amin,Kazemnejadi, Milad,Hamah-Ameen, Baram Ahmed
-
-
- Catalytic alcohol oxidation using cationic Schiff base manganeseIII complexes with flexible diamino bridge
-
Four Schiff base manganese(III) complexes with derivatives of [(R,R)-N,N’-bis(salicy1idene)-1,2-cyclohexanediaminato)] including substituents on salicylaldehyde such as 3-methoxy, 3,5-di-tert-butyl and 3,5-chloro were synthesized and characterized using a combination of IR, UV–Vis, and HR ESI-MS techniques. The catalytic activity of these complexes was tested in the oxidation of 1-phenylethanol to acetophenone, revealing very good performances for all of the four manganese complexes. The catalytic reactions were carried out in the presence of tert-butyl hydroperoxide (TBHP) as oxidant and imidazole as co-catalyst. Complex Mn-4, bearing electron withdrawing [(R,R)-N,N’-bis(3,5-di-chloro-salicylidene)-1,2-cyclohexanediaminato)] ligand was found to be the most stable of the tested Mn(III) complexes and was selected for the oxidation of several primary and secondary alcohols.
- Kakavand, Meysam,Mastrorilli, Piero,Mesto, Ernesto,Neshat, Abdollah,Osanlou, Farzane,Schingaro, Emanuela,Todisco, Stefano
-
-
- Merging N-Hydroxyphthalimide into Metal-Organic Frameworks for Highly Efficient and Environmentally Benign Aerobic Oxidation
-
Two highly efficient metal-organic framework catalysts TJU-68-NHPI and TJU-68-NDHPI have been successfully synthesized through solvothermal reactions of which the frameworks are merged with N-hydroxyphthalimide (NHPI) units, resulting in the decoration of pore surfaces with highly active nitroxyl catalytic sites. When t-butyl nitrite (TBN) is used as co-catalyst, the as-synthesized MOFs are demonstrated to be highly efficient and recyclable catalysts for a novel three-phase heterogeneous oxidation of activated C?H bond of primary and secondary alcohols, and benzyl compounds under mild conditions. Based on the high efficiency and selectivity, an environmentally benign system with good sustainability, mild conditions, simple work-up procedure has been established for practical oxidation of a wide range of substrates.
- Wang, Man,Liang, Gan,Wang, Yunhao,Fan, Tao,Yuan, Baoling,Liu, Mingxian,Yin, Ying,Li, Liangchun
-
supporting information
p. 9674 - 9685
(2021/06/09)
-
- Green synthesis of a vanadium(V) Schiff base complex by grinding method: study on its catalytic and anti-bacterial activity
-
A facile protocol was developed for the green synthesis of a Schiff base and its vanadium(V) complex. The compounds were derived from salicylaldehyde, diethylenetriamine and vanadyl sulfate by applying grinding method to overcome environmental issues with solvents. The reactions took place rapidly and products were isolated pure. The compounds were characterized with elemental, EDX, mass spectrometry, magnetic susceptibility, molar conductance, UV-vis, FTIR and NMR analysis. The synthesized vanadium(V) complex was an efficient and selective catalyst towards oxidation of organic sulfides and alcohols. The oxidation reactions were conducted under microwave irradiation as well as conventional heating. A reaction mechanism has been proposed for the catalytic oxidation reactions. The mechanism was further established by using GAUSSIAN16 suite. The complex also showed good anti-bacterial activity against Gram-positive and Gram-negative bacteria.
- Boruah, Jeena Jyoti,Bhatt, Zankhana S.,Nathani, Chirag R.,Bambhaniya, Vaishali J.,Guha, Ankur Kanti,Das, Siva Prased
-
p. 2055 - 2068
(2021/06/27)
-
- The Highly Effective Cobalt Based Metal–Organic Frameworks Catalyst for One Pot Oxidative Esterification Under Mild Conditions
-
The cobalt-based metal organic frameworks (Co-MOFs) catalyst has been prepared with using terephthalic acid and 4,4′-bipyridine as organic linkers by facile solvothermal method for one pot oxidative esterification. The prepared catalyst was pyrolysed at different temperature and then applied for oxidation of aldehyde using molecular oxygen as benign oxidant under mild conditions. The Co-MOFs pyrolysed at 800?°C (denoted as Co-MOFs-800) catalyst exhibited excellent catalytic activity, selectivity and recyclability toward the oxidative esterification of benzaldehydes. Furthermore, it can be reused up to 5 runs without significant loss of activity. Graphic Abstract: [Figure not available: see fulltext.]
- Chindawong, Chakkresit,Mekrattanachai, Pagasukon,Setthaya, Naruemon,Song, Wei Guo,Zhu, Lei
-
-
- C70Fullerene Catalyzed Photoinduced Aerobic Oxidation of Benzylamines to Imines and Aldehydes
-
C70 fullerene catalyzed photoinduced oxidation of benzylic amines at ambient conditions has been explored here. The developed strategy's main feature includes the additive/oxidant-free conversion of benzylic amine to corresponding imine and aldehydes. The reaction manifests broad substrate scope with excellent function group leniency and is applicable up to the gram scale. Further, symmetrical secondary amines can also be synthesized from benzylic amine in a one-pot two-step process. Various experiments and density functional theory studies revealed that the current reaction involves the generation of reactive oxygen species, single electron transfer reaction, and benzyl radical formation as key steps under photocatalytic conditions.
- Kumar, Inder,Kumar, Rakesh,Gupta, Shiv Shankar,Sharma, Upendra
-
supporting information
p. 6449 - 6457
(2021/05/29)
-
- One-Pot Direct Oxidation of Primary Amines to Carboxylic Acids through Tandem ortho-Naphthoquinone-Catalyzed and TBHP-Promoted Oxidation Sequence
-
Biomimetic oxidation of primary amines to carboxylic acids has been developed where the copper-containing amine oxidase (CuAO)-like o-NQ-catalyzed aerobic oxidation was combined with the aldehyde dehydrogenase (ALDH)-like TBHP-mediated imine oxidation protocol. Notably, the current tandem oxidation strategy provides a new mechanistic insight into the imine intermediate and the seemingly simple TBHP-mediated oxidation pathways of imines. The developed metal-free amine oxidation protocol allows the use of molecular oxygen and TBHP, safe forms of oxidant that may appeal to the industrial application.
- Kim, Hun Young,Oh, Kyungsoo,Si, Tengda
-
supporting information
p. 18150 - 18155
(2021/12/09)
-
- Aerobic epoxidation of styrene over Zr-based metal-organic framework encapsulated transition metal substituted phosphomolybdic acid
-
Catalytic epoxidation of styrene with molecular oxygen is regarded as an eco-friendly alternative to producing industrially important chemical of styrene oxide (STO). Recent efforts have been focused on developing highly active and stable heterogeneous catalysts with high STO selectivity for the aerobic epoxidation of styrene. Herein, a series of transition metal monosubstituted heteropolyacid compounds (TM-HPAs), such as Fe, Co, Ni or Cu-monosubstituted HPA, were encapsulated in UiO-66 frameworks (denoted as TM-HPA@UiO-66) by direct solvothermal method, and their catalytic properties were investigated for the aerobic epoxidation of styrene with aldehydes as co-reductants. Among them, Co-HPA@UiO-66 showed relatively high catalytic activity, stability and epoxidation selectivity at very mild conditions (313 K, ambient pressure), that can achieve 82 % selectivity to STO under a styrene conversion of 96 % with air as oxidant and pivalaldehyde (PIA) as co-reductant. In addition, the hybrid composite catalyst can also efficiently catalyze the aerobic epoxidation of a variety of styrene derivatives. The monosubstituted Co atoms in Co-HPA@UiO-66 are the main active sites for the aerobic epoxidation of styrene with O2/PIA, which can efficiently converting styrene to the corresponding epoxide through the activation of the in-situ generated acylperoxy radical intermediate.
- Hu, Dianwen,Song, Xiaojing,Zhang, Hao,Chang, Xinyu,Zhao, Chen,Jia, Mingjun
-
-
- Rapid, chemoselective and mild oxidation protocol for alcohols and ethers with recyclable N-chloro-N-(phenylsulfonyl)benzenesulfonamide
-
Chlorine is the 20th most abundant element on the earth compared to bromine, iodine, and fluorine, a sulfonimide reagent, N-chloro-N-(phenylsulfonyl)benzenesulfonamide (NCBSI) was identified as a mild and selective oxidant. Without activation, the reagent was proved to oxidize primary and secondary alcohols as well as their symmetrical and mixed ethers to corresponding aldehydes and ketones. With recoverable PS-TEMPO catalyst, selective oxidation over chlorination of primary and secondary alcohols and their ethers with electron-donating substituents was achieved. The reagent precursor of NCBSI was recovered quantitatively and can be reused for synthesizing NCBSI.
- Badani, Purav,Chaturbhuj, Ganesh,Ganwir, Prerna,Misal, Balu,Palav, Amey
-
supporting information
(2021/06/03)
-
- La(OH)3nanoparticles immobilized on Fe3O4@chitosan composites as novel magnetic nanocatalysts for sonochemical oxidation of benzyl alcohol to benzaldehyde
-
This work introduces an eco-friendly method for immobilization of La(OH)3 nanoparticles on modified Fe3O4 nanoparticles. The structural and morphological characteristics of the nanocatalyst were determined by various analytical techniques including, FT-IR, EDS, FESEM, VSM and XRD. The catalytic efficiency of the Fe3O4@Cs/La(OH)3 composite as a heterogeneous nanocatalyst was evaluated by selective oxidation of benzylic alcohols to aldehydes. The optimum reaction conditions including time, temperature, nanocatalyst dosage, and solvent were investigated for ultrasound-assisted oxidation processes. Furthermore, the magnetic nanocatalyst was recovered up to seven times without considerable activity loss. Furthermore, the proposed nanocomposite had a remarkable effect on reducing the reaction time and enhancing the yield. This journal is
- Fadaeian, Manoochehr,Ghomi, Javad Safaei,Javidfar, Fereshteh
-
p. 35988 - 35993
(2021/12/02)
-
- Selective aerobic oxidation of benzylic and allylic alcohols catalyzed by Cu(OAc)2/TEMPO/Et2NH
-
Selective oxidation of benzylic and allylic alcohols to their corresponding aldehyde/ketone derivative without affecting saturated alcohols is still a challenging endeavor in organic synthesis. Various metal complexes, especially the copper complexes in the presence of TEMPO are being used very often for such transformations under aerobic conditions, but they are not selective to allylic and benzylic alcohols. The use of copper salt for oxidation of alcohols in the absence of a ligand are very scarcely studied except for the one catalyzed by CuCl/TEMPO where chloride inhibition and lack of selective oxidation have been noted upon use of CuCl2. Herein we report a Cu(OAc)2 catalyzed and TEMPO mediated selective aerobic oxidation of benzylic and allylic alcohols to aldehyde/ketone in the presence of Et2NH. The method avoids pre-synthesis of the catalyst as in the case of Cu(II)/(I) complexes/TEMPO catalyzed oxidation reactions, requires low catalyst loading, employs cheaper copper salt, and gives excellent selectivity for oxidation of benzylic and allylic alcohols.
- Bez, Ghanashyam,Gogoi, Achinta,Pasupuleti, Bala Gangadhar
-
p. 589 - 597
(2021/09/28)
-
- Selective alcohol oxidation catalysed BY FeCl3 /novel glycine functionalised IONIC liquid
-
An effective and eco-friendly technique were designated for quick alcohol oxidation by glycine functionalised imidazolium ionic liquids in presence of FeCl3 at ambient-temperature. No over the primary alcohols oxidation to carbonyl compounds was observed in presence of this FeCl3/[Gmim]Cl. These benefits of the catalyst resulted mainly from the circumstance with alcohols-H2O2, and the Fe3+ was coordinated by the immobilized IL to permitted both reactants to access the active sites of the catalyst effectively. The catalyst recycled nine times without loss of activity.
- Gopalsamy Selvaraj, Ganesh,Karthikeyan, Parasuraman,Manickam, Deepa,Selvarasu, Uthayanila
-
-
- A Synergistic Magnetically Retrievable Inorganic-Organic Hybrid Metal Oxide Catalyst for Scalable Selective Oxidation of Alcohols to Aldehydes and Ketones
-
Herein, we report a synergistic silica coated magnetic Fe3O4 catalyst functionalized with nitrogen rich organic moieties and immobilized with cobalt metal ion (FNP-5) for selective oxidation of alcohols to aldehydes and ketones using tert-butyl hydroperoxide (TBHP) as oxidant. The catalyst was rigorously characterized via several techniques which delineate its core-shell structure, magnetic behavior, phase and crystal structure. The Co(III) acts as the active catalytic center for selective oxidation reaction. The control reactions revealed radical mechanistic pathway assisted by the synergism induced by the inorganic-organic hybrid nature of FNP-5. The other features of current protocol involve neat reaction conditions, high TOF values, scalability of product and low E-factor value (1.92). Moreover, FNP-5 could be effortlessly separated via an external magnet, displays recyclability over eight catalytic cycles and exhibits structural integrity even after rigorous use. Overall, these results manifest the understanding of synergistic architectures as sustainable surrogates for selective oxidation reactions.
- Mittal, Rupali,Awasthi, Satish Kumar
-
p. 4799 - 4813
(2021/09/30)
-
- A TEMPO-Functionalized Ordered Mesoporous Polymer as a Highly Active and Reusable Organocatalyst
-
The properties of high stability, periodic porosity, and tunable nature of ordered mesoporous polymers make these materials ideal catalytic nanoreactors. However, their application in organocatalysis has been rarely explored. We report herein for the first time the incorporation of a versatile organocatalyst, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), into the pores of an FDU-type mesoporous polymer via a pore surface engineering strategy. The resulting FDU-15-TEMPO possesses a highly ordered mesoporous organic framework and enhanced stability, and shows excellent catalytic activity in the selective oxidation of alcohols and aerobic oxidative synthesis of 2-substituted benzoxazoles, benzimidazoles and benzothiazoles. Moreover, the catalyst can be easily recovered and reused for up to 7 consecutive cycles.
- Guo, Ying,Wang, Wei David,Li, Shengyu,Zhu, Yin,Wang, Xiaoyu,Liu, Xiao,Zhang, Yuan
-
supporting information
p. 3689 - 3694
(2021/09/29)
-
- Nitrosoarene-Catalyzed HFIP-Assisted Transformation of Arylmethyl Halides to Aromatic Carbonyls under Aerobic Conditions
-
A rare metal-free nucleophilic nitrosoarene catalysis accompanied by highly hydrogen-bond-donor (HBD) solvent, 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), organocatalytically converts arylmethyl halides to aromatic carbonyls. This protocol offers an effective means to access a diverse array of aromatic carbonyls with good chemoselectivity under mild reaction conditions. The activation of arylmethyl halides by HFIP to generate stable carbocation and autoxidation of in situ generated hydroxylamine to nitrosoarene in the presence of atmospheric O2 are the keys to success.
- Pradhan, Suman,Sharma, Vishali,Chatterjee, Indranil
-
supporting information
p. 6148 - 6152
(2021/08/03)
-
- Zirconium-based metal-organic framework as an efficiently heterogeneous photocatalyst for oxidation of benzyl halides to aldehydes
-
The development of efficient heterogeneous catalysts for fine chemical synthesis is critical for practical applications. Herein, for the first time, the zirconium-based metal-organic framework (UiO-66-NH2) is applied as an efficiently heterogeneous photocatalyst for conversion of benzyl halides to corresponding aldehydes with high selectivity (about 80 %) and conversion (up to 99 %) in the presence of oxygen and DMF as solvent. Through a series of experiments and analysis, the reaction mechanism is proposed to involve nucleophilic attack of the N-oxide. This study provides a general, environmental and high selective method to prepare benzaldehydes and broadens the application fields of UiO-66-NH2.
- Xue, Ping,Huang, Jiming,Lin, Liguang,Li, Rong,Tang, Mi,Wang, Zhengbang
-
-
- Hydroxyl radical-mediated oxidative cleavage of CC bonds and further esterification reaction by heterogeneous semiconductor photocatalysis
-
A hydroxyl radical-mediated aerobic cleavage of alkenes and further sequence esterification reaction for the preparation of carbonyl compounds have been developed by using tubular carbon nitride (TCN) as a general heterogeneous photocatalyst under an oxygen atmosphere with visible light irradiation. This protocol has an excellent substrate scope and gives the desired aldehydes, ketones and esters in moderate to high yields. Importantly, this metal-free procedure employed photogenerated hydroxyl radicals in situ as green oxidation active species, avoiding the present additional initiators. The reaction could be carried out under solar light irradiation and was applicable to large-scale reactions. Furthermore, the recyclable TCN catalyst could be used several times without a significant loss of activities.
- Hong, Mei,Jia, Rui,Miao, Hongyan,Ni, Bangqing,Niu, Tengfei,Wang, Hui
-
p. 6591 - 6597
(2021/09/10)
-
- Selective oxidation of alkenes to carbonyls under mild conditions
-
Herein, a practical and sustainable method for the synthesis of aldehydes, ketones, and carboxylic acids from an inexpensive olefinic feedstock is described. This transformation features very sustainable and mild conditions and utilizes commercially available and inexpensive tetrahydrofuran as the additive, molecular oxygen as the sole oxidant and water as the solvent. A wide range of substituted alkenes were found to be compatible, providing the corresponding carbonyl compounds in moderate-to-good yields. The control experiments demonstrated that a radical mechanism is responsible for the oxidation reaction.
- Huo, Jie,Xiong, Daokai,Xu, Jun,Yue, Xiaoguang,Zhang, Pengfei,Zhang, Yilan
-
supporting information
p. 5549 - 5555
(2021/08/16)
-
- Method for generating benzaldehyde by catalyzing alpha-monosubstituted styrene to be oxidized by N-hydroxyphthalimide
-
The invention discloses a method for generating benzaldehyde by catalyzing alpha-mono-substituted styrene to be oxidized through N-hydroxyphthalimide. According to the method, N-hydroxyphthalimide isused as a catalyst, oxygen is used as an oxidizing agent, and an alpha mono-substituted styrene compound is oxidized in an organic solvent to obtain the benzaldehyde derivative. The method has the advantages of simple reaction operation, low cost, mild conditions, high yield, no heavy metal pollution and the like.
- -
-
Paragraph 0045-0047
(2021/01/24)
-
- V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
-
The versatile application of different functional groups such as alcohols (1° and 2°), alkyl arenes, and (aryl)olefins to construct carbon-oxygen bond via oxidation is an area of intense research. Here, we report a reusable heterogeneous V2O5@TiO2 catalyzed selective oxidation of various functionalities utilizing different mild and eco-compatible oxidants under greener reaction conditions. The method was successfully applied for the alcohol oxidation, oxidative scission of styrenes, and benzylic C?H oxidation to their corresponding aldehydes and ketones. The utilization of mild and eco-friendly oxidizing reagents such as K2S2O8, H2O2 (30 % aq.), TBHP (70 % aq.), broad substrate scope, gram-scale synthesis, and catalyst recyclability are notable features of the developed protocol.
- Upadhyay, Rahul,Kumar, Shashi,Maurya, Sushil K.
-
p. 3594 - 3600
(2021/07/02)
-
- Thiol-initiated photocatalytic oxidative cleavage of the C=C bond in olefins and its extension to direct production of acetals from olefins
-
The oxidative cleavage of olefins to produce aldehydes/ketones is an important reaction in organic syntheses. In this manuscript, a mild and operationally simple protocol for the aerobic oxidation of olefins to produce carbonyl compounds was realized over ZnIn2S4under visible light, using air as the oxidant and a thiol as the initiator. It was proposed that the photogenerated holes over ZnIn2S4attack the thiol to produce thiyl radicals, which initiate the oxidative cleavage of the C=C bond in olefins to produce aldehydes/ketones. By further coupling with the condensation between the as-obtained aldehydes/ketones and alcohols, this strategy can also be applied to the production of different acetals directly from the olefins. This study demonstrates a new pathway to realize the oxidative cleavage of olefins to produce aldehydes/ketones, and also provides a new protocol for the production of acetals directly from the olefins.
- Wang, Xinglin,Li, Yuanyuan,Li, Zhaohui
-
p. 1000 - 1006
(2021/02/26)
-
- g-C3N4@Ce-MOF Z-scheme heterojunction photocatalyzed cascade aerobic oxidative functionalization of styrene
-
A special composite of the cerium-based metal-organic framework (Ce-UiO-66) modified with graphitic carbon nitride nanosheets (g-C3N4) has been synthesized. In order to make a comparison, a series of composites comprising g-C3N4and Ce-MOF were synthesized as well. Their structural features were investigated using Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), sorption of nitrogen (BET and BJH), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), X-ray fluorescence spectroscopy (XRF) and diffuse reflectance UV-Vis spectroscopy (UV-Vis DRS) and electron spin resonance (ESR) techniques. According to the obtained results, it was found that nanosheets of mesoporous g-C3N4act as linkers between the cerium sites, playing a critical role in the formation of composites. In fact, the embedded g-C3N4nanoparticles in the Ce-MOF cause a new kind of meso-porosity. Moreover, the coordination of nitrogen atoms in the graphitic carbon nitride structure to cerium atoms of the crystal brings about substantial changes in the optical properties, increasing the photoreactivity. On the other hand, since there is a physical contact between Ce-UiO-66 and g-C3N4in the composite, the unaltered pore volume and optical properties lead to the formation of a physical mixture rather than a composite. The g-C3N4@Ce-MOF as a photocatalyst was employed in photocatalytic aerobic oxidative Hantzsch pyridine synthesis of styrene and indicated high performance under visible light. The stability and reusability of g-C3N4@Ce-MOF were also examined and showed high efficiency up to the 5th run. Besides, the PXRD and FT-IR analyses taken from the retrieved g-C3N4@Ce-MOF nanocomposite confirmed the catalyst stability after the completion of the cascade aerobic oxidative reaction. Despite the photocatalytic performance, the synergistic effect of open metal sites in the MOF as Lewis acid and nitrogen in g-C3N4have greatly improved the efficiency of the catalyst. Moreover, the study of the reaction mechanism using ESR indicates the positive effect of composite formation on the performance of the photocatalytic aerobic oxidation reaction by the superoxide radical (O2˙—), as a selective oxidant species.
- Karimia, Meghdad,Sadeghia, Samira,Gavinehroudi, Reza Ghahremani,Mohebali, Haleh,Mahjoub, Alireza,Heydari, Akbar
-
p. 6671 - 6681
(2021/04/22)
-
- A highly stable metal-organic framework with cubane-like clusters for the selective oxidation of aryl alkenes to aldehydes or ketones
-
Triazine derivatives, a class of electron-deficient π-conjugated molecules with high photochemical activity and excellent luminescent characteristics, have been utilized as a kind of electron-acceptor for the construction of molecular cages, luminescent and photochromic materials. In this paper, a novel and highly stable MOF with cubane-like clusters, [Co4(SO4)3(F)3(tpt)2(tatb)] (1) (tpt = 2,4,6-tris-(4-pyridyl)-1,3,5-triazine, H3tatb = 4,4′,4′′-(1,3,5-triazine-2,4,6-triyl)tribenzoic acid), has been successfully synthesized based on a triazine derivative, and possesses unprecedented sulfate- and fluoride-bridged cubane-type tetranuclear cobalt clusters and a 3D + 3D → 3D open framework. Compound1shows a rather high BET surface area and exhibits excellent thermal stability and high chemical stability in common solvents and even in acidic or basic solutions (in a pH range from 4 to 12). Moreover, catalytic measurements show that compound1is an excellent heterogeneous catalyst for the selective oxidation of aryl alkenes to aldehydes or ketones with conversions of 97%.
- He, Chixian,Liu, Jiaming,Liu, Jian-Jun,Liu, Teng,Shen, Xianfu,Shen, Xiang
-
p. 4667 - 4673
(2021/07/11)
-
- Method for preparing aldehyde compounds by oxidative cleavage of carbon-carbon bonds of terminal alkene compounds
-
The invention discloses a method for preparing aldehyde compounds by oxidizing and breaking carbon-carbon bonds of terminal alkene compounds. The method comprises the following steps: adding an alkene-terminated compound, an additive and a nitrogen-doped mesoporous carbon-loaded monatomic catalyst into a fatty primary alcohol solvent, putting into a pressure container, sealing, introducing oxygen source gas with a certain pressure, controlling the pressure of the oxygen source gas to be 0.1-1MPa and the reaction temperature to be 80-150 DEG C, and obtaining a reaction product, namely the aldehyde compound. The nitrogen-doped mesoporous carbon-loaded monatomic catalyst adopted by the invention is high in activity, the highest separation yield of the aldehyde compound as a reaction product reaches 99%, the method is wide in application range, the reaction conditions are easy to control, the catalyst can be recycled, the post-treatment is simple, and the method is suitable for industrial production.
- -
-
Paragraph 0051-0052; 0089-0090
(2021/06/06)
-
- Fe-S Catalyst Generated in Situ from Fe(III)- And S3?--Promoted Aerobic Oxidation of Terminal Alkenes
-
An iron-sulfur complex formed by the simple mixture of FeCl3 with S3?- generated in situ from K2S is developed and applied to selective aerobic oxidation of terminal alkenes. The reaction was carried out under an atmosphere of O2 (balloon) and could proceed on a gram scale, expanding the application of S3?- in organic synthesis. This study also encourages us to explore the application of an Fe-S catalyst in organic reactions.
- Ai, Jing-Jing,Huang, Cheng-Mi,Li, Jian,Liu, Bei-Bei,Rao, Weidong,Wang, Fei,Wang, Shun-Yi
-
supporting information
p. 4705 - 4709
(2021/06/28)
-
- Visible-Light-Driven Oxidative Cleavage of Alkenes Using Water-Soluble CdSe Quantum Dots
-
The oxidative cleavage of C=C bonds is an important chemical reaction, which is a popular reaction in the photocatalytic field. However, high catalyst-loading and low turnover number (TON) are general shortcomings in reported visible-light-driven reactions. Herein, the direct oxidative cleavage of C=C bonds through water-soluble CdSe quantum dots (QDs) is described under visible-light irradiation at room temperature with high TON (up to 3.7×104). Under the same conditions, water-soluble CdSe QDs could also oxidize sulfides to sulfoxides with 51–84 % yields and TONs up to 3.4×104. The key features of this photocatalytic protocol include high TONs, wide substrates scope, low catalyst loadings, simple and mild reaction conditions, and molecular O2 as the oxidant.
- Li, Jianing,Zhao, Jingnan,Ma, Cunfei,Yu, Zongyi,Zhu, Hongfei,Yun, Lei,Meng, Qingwei
-
p. 4985 - 4992
(2021/10/16)
-
- Aerobic oxidative C?C bond cleavage of aromatic alkenes by a high valency iron-containing perovskite catalyst
-
High valency iron-containing perovskite catalyst BaFeO3-dcould efficiently promote the additive-free oxidative C?C bond cleavage of various aromatic alkenes to the corresponding aldehydes or ketones using O2as the sole oxidant. This system was applicable to the gram-scale oxidation of 1,1-diphenylethylene, in which 2.71 g (75% yield) of the analytically pure ketone could be isolated.
- Shibata, Satomi,Kamata, Keigo,Hara, Michikazu
-
p. 2369 - 2373
(2021/04/22)
-
- Tunable Artificial Enzyme-Cofactor Complex for Selective Hydrolysis of Acetals
-
Enzymes frequently use unimpressive functional groups such as weak carboxylic acids for efficient, highly selective catalysis including hydrolysis of acetals and even amides. Much stronger acids generally have to be used for such purposes in synthetic systems. We report here a method to position an acidic group near the acetal oxygen of 2-(4-nitrophenyl)-1,3-dioxolane bound by an artificial enzyme. The hydrolytic activity of the resulting artificial enzyme-cofactor complex was tuned by the number and depth of the active site as well as the hydrophobicity and acidity of the cofactor. The selectivity of the complex was controlled by the size and shape of the active site and enabled less reactive acetals to be hydrolyzed over more reactive ones.
- Bose, Ishani,Fa, Shixin,Zhao, Yan
-
p. 1701 - 1711
(2021/02/05)
-
- A Magnetically Recyclable Palladium-Catalyzed Formylation of Aryl Iodides with Formic Acid as CO Source: A Practical Access to Aromatic Aldehydes
-
A magnetically recyclable palladium-catalyzed formylation of aryl iodides under CO gas-free conditions has been developed by using a bidentate phosphine ligand-modified magnetic nanoparticles-anchored- palladium(II) complex [2P-Fe 3O 4@SiO 2-Pd(OAc) 2] as catalyst, yielding a wide variety of aromatic aldehydes in moderate to excellent yields. Here, formic acid was employed as both the CO source and the hydrogen donor with iodine and PPh 3as the activators. This immobilized palladium catalyst can be obtained via a simple preparative procedure and can be facilely recovered simply by using an external magnetic field, and reused at least 9 times without any apparent loss of catalytic activity.
- You, Shengyong,Zhang, Rongli,Cai, Mingzhong
-
p. 1962 - 1970
(2021/01/25)
-
- Atomically Dispersed Pt-N3C1Sites Enabling Efficient and Selective Electrocatalytic C-C Bond Cleavage in Lignin Models under Ambient Conditions
-
Selective cleavage of C-C linkages is the key and a challenge for lignin degradation to harvest value-added aromatic compounds. To this end, electrocatalytic oxidation presents a promising technique by virtue of mild reaction conditions and strong sustainability. However, the existing electrocatalysts (traditional bulk metal and metal oxides) for C-C bond oxidative cleavage suffer from poor selectivity and low product yields. We show for the first time that atomically dispersed Pt-N3C1sites planted on nitrogen-doped carbon nanotubes (Pt1/N-CNTs), constructed via a stepwise polymerization-carbonization-electrostatic adsorption strategy, are highly active and selective toward Cα-Cβbond cleavage in β-O-4 model compounds under ambient conditions. Pt1/N-CNTs exhibits 99% substrate conversion with 81% yield of benzaldehyde, which is exceptional and unprecedented compared with previously reported electrocatalysts. Moreover, Pt1/N-CNTs using only 0.41 wt % Pt achieved a much higher benzaldehyde yield than those of the state-of-the-art bulk Pt electrode (100 wt % Pt) and commercial Pt/C catalyst (20 wt % Pt). Systematic experimental investigation together with density functional theory (DFT) calculation suggests that the superior performance of Pt1/N-CNTs arises from the atomically dispersed Pt-N3C1sites facilitating the formation of a key Cβradical intermediate, further inducing a radical/radical cross-coupling path to break the Cα-Cβbond. This work opens up opportunities in lignin valorization via a green and sustainable electrochemical route with ultralow noble metal usage.
- Cui, Tingting,Ma, Lina,Wang, Shibin,Ye, Chenliang,Liang, Xiao,Zhang, Zedong,Meng, Ge,Zheng, Lirong,Hu, Han-Shi,Zhang, Jiangwei,Duan, Haohong,Wang, Dingsheng,Li, Yadong
-
supporting information
p. 9429 - 9439
(2021/07/19)
-
- Palladium-Catalyzed Reductive Carbonylation of (Hetero) Aryl Halides and Triflates Using Cobalt Carbonyl as CO Source
-
An efficient protocol for the reductive carbonylation of (hetero) aryl halides and triflates under CO gas-free conditions using Pd/Co2(CO)8 and triethylsilane has been developed. The mild reaction conditions, enhanced chemoselectivity and, easy access to heterocyclic and vinyl carboxaldehydes highlights its importance in organic synthesis.
- Dogga, Bhushanarao,Joseph, Jayan T.,Kumar, C. S. Ananda
-
p. 309 - 313
(2020/12/23)
-
- Cs 2CO 3-Mediated Regio- And Stereoselective Sulfonylation of 1,1-Dibromo-1-alkenes with Sodium Sulfinates
-
A highly selective synthesis of (Z)-1-bromo-1-sulfonyl alkenes via Cs 2CO 3-promoted sulfonylation of 1,1-dibromo-1-alkenes with sodium sulfinates is described. Notably, using excess amounts of Cs 2CO 3and sodium sulfinate in such a reaction regenerated the parent aldehyde. Interestingly, the reaction of 1-(2,2-dibromovinyl)-2-nitrobenzene in the presence of sulfinates and Cs 2CO 3produced isatin. The Sonogashira cross coupling of synthesized (Z)-1-bromo-1-sulfonyl alkenes with phenylacetylene gave selectively the corresponding sulfonylalkynyl alkenes.
- Shiri, Morteza,Salehi, Parvin,Mohammadpour, Zeinab,Salehi, Peyman,Notash, Behrouz
-
p. 1149 - 1156
(2020/10/21)
-
- Liquid-phase oxidation of olefins with rare hydronium ion salt of dinuclear dioxido-vanadium(V) complexes and comparative catalytic studies with analogous copper complexes
-
Homogeneous liquid-phase oxidation of a number of aromatic and aliphatic olefins was examined using dinuclear anionic vanadium dioxido complexes [(VO2)2(salLH)]? (1) and [(VO2)2(NsalLH)]? (2) and dinuclear copper complexes [(CuCl)2(salLH)]? (3) and [(CuCl)2(NsalLH)]? (4) (reaction of carbohydrazide with salicylaldehyde and 4-diethylamino salicylaldehyde afforded Schiff-base ligands [salLH4] and [NsalLH4], respectively). Anionic vanadium and copper complexes 1, 2, 3, and 4 were isolated in the form of their hydronium ion salt, which is rare. The molecular structure of the hydronium ion salt of anionic dinuclear vanadium dioxido complex [(VO2)2(salLH)]? (1) was established through single-crystal X-ray analysis. The chemical and structural properties were studied using Fourier transform infrared (FT-IR), ultraviolet–visible (UV–Vis), 1H and 13C nuclear magnetic resonance (NMR), electrospray ionization mass spectrometry (ESI-MS), electron paramagnetic resonance (EPR) spectroscopy, and thermogravimetric analysis (TGA). In the presence of hydrogen peroxide, both dinuclear vanadium dioxido complexes were applied for the oxidation of a series of aromatic and aliphatic alkenes. High catalytic activity and efficiency were achieved using catalysts 1 and 2 in the oxidation of olefins. Alkenes with electron-donating groups make the oxidation processes easy. Thus, in general, aromatic olefins show better substrate conversion in comparison to the aliphatic olefins. Under optimized reaction conditions, both copper catalysts 3 and 4 fail to compete with the activity shown by their vanadium counterparts. Irrespective of olefins, metal (vanadium or copper) complexes of the ligand [salLH4] (I) show better substrate conversion(%) compared with the metal complexes of the ligand [NsalLH4] (II).
- Maurya, Abhishek,Haldar, Chanchal
-
-
- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
-
A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method includes the steps of: (A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst; wherein, the catalyst is represented by Formula (II): M(O)mL1yL2z??(II);wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and(B) mixing the compound with an unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):
- -
-
Paragraph 0071; 0077
(2021/07/10)
-
- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
-
A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method comprises the following step: (A) providing a compound (I) with an unsaturated double bond, a reagent with trifluoromethyl, and a catalyst; wherein the catalyst is represented by the following formula (II): M(O)mL1yL2z (II); wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and (B) mixing the compound with an unsaturated double bond and the reagent with a trifluoromethyl to perform an oxidation of the compound with the unsaturated double bond by using the catalyst at air or an oxygen condition to get a compound presented as formula (III):
- -
-
Paragraph 0053-0054; 0062-0063
(2021/03/19)
-
- Surfactant-Assisted Ozonolysis of Alkenes in Water: Mitigation of Frothing Using Coolade as a Low-Foaming Surfactant
-
Aqueous-phase ozonolysis in the atmosphere is an important process during cloud and fog formation. Water in the atmosphere acts as both a reaction medium and a reductant during the ozonolysis. Inspired by the atmospheric aqueous-phase ozonolysis, we herein report the ozonolysis of alkenes in water assisted by surfactants. Several types of surfactants, including anionic, cationic, and nonionic surfactants, were investigated. Although most surfactants enhanced the solubility of alkenes in water, they also generated excessive foaming during the ozone bubbling, which led to the loss of products. Mitigation of the frothing was accomplished by using Coolade as a nonionic and low-foaming surfactant. Coolade-assisted ozonolysis of alkenes in water provided the desired carbonyl products in good yields and comparable to those achieved in organic solvents. During the ozonolysis reaction, water molecules trapped within the polyethylene glycol region of Coolade were proposed to intercept the Criegee intermediate to provide a hydroxy hydroperoxide intermediate. Decomposition of the hydroxy hydroperoxide led to formation of the carbonyl product without the need for a reductant typically required for the conventional ozonolysis using organic solvents. This study presents Coolade as an effective surfactant to improve the solubility of alkenes while mitigating frothing during the ozonolysis in water.
- Buntasana, Supanat,Hayashi, Jun,Klumphu, Piyatida,Padungros, Panuwat,Saetung, Prakorn,Vilaivan, Tirayut
-
supporting information
(2022/02/23)
-
- Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group
-
Chemoselective sulfonylation and isonitrilation reactions for the divergent synthesis of valuable diarylmethyl sulfones and isonitrile diarylmethanes starting from easy-to-synthesize para-quinone methides (p-QMs) and commercially abundant p-toluenesulfonylmethyl isocyanide (TosMIC) by using respectively zinc iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalysts were developed. The distinguishing feature of this method is that TosMIC plays a dual role from the same substrates in the reaction: as a sulfonyl source or as an isonitrile source. The synthetic utility of this protocol was also demonstrated in the synthesis of difluoroalkylated diarylmethane 5 and diarylmethane ketone derivatives 6 and 7, which are important core structures in natural products and medicines.
- Chen, Yuan,Huang, Run,Li, Yong,Liu, Tong,Qu, Chuanhua,Song, Guiting
-
p. 2822 - 2831
(2022/01/03)
-
- Aqueous extract of Shikakai; a green solvent for deoximation reaction: Mechanistic approach from experimental to theoretical
-
This article describes a green method for regeneration of carbonyl compounds from various types of oxime compounds under microwave radiation using I2 and aqueous saponin solution isolated from Shikakai. Effect of saponin concentration on yield percentage of regenerated different types of carbonyl compounds has been discussed. A correlation has been established between saponin concentration and yield percentage of carbonyl compounds. Mechanism of interaction between oxime and saponin is established on the basis of density functional theory. In addition, the quantum chemical parameters for saponin have been determined. Furthermore, electrostatic surface analysis of the saponin is carried out to confirm the mechanism of interaction between saponin and oximes.
- Das, Debadutta,Kudrat-E-Zahan, Md.,Mahal, Ahmed,Mohapatra, Ranjan K.,Parhi, Pankaj K.,Sahu, Raghaba,Sarangi, Ashish K.
-
-
