446-52-6Relevant articles and documents
Oxidation of Alcohols to Carbonyl Compounds Catalyzed by Oxo-Bridged Dinuclear Cerium Complexes with Pentadentate Schiff-Base Ligands under a Dioxygen Atmosphere
Shirase, Satoru,Shinohara, Koichi,Tsurugi, Hayato,Mashima, Kazushi
, p. 6939 - 6947 (2018)
Ionic mononuclear and neutral dinuclear complexes of cerium(III) 3-L1-3-L9 bearing a series of dianionic pentadentate Schiff-base ligands were synthesized, characterized, and used as catalysts for N-oxyl radical-free aerobic alcohol oxidation. Reactions of Ce(NO3)3·6H2O with o-tert-butyl-substituted sterically hindered ligands NH(CH2CH2-Rfnet=CHC6H2-3-(tBu)-5-R2-2-OH)2 (for L1H2, R2 = tBu; for L2H2, R2 = OMe; and for L3H2, R2 = H) in the presence of triethylamine afforded the corresponding anionic cerium complexes [HNEt3][Ce(L1-3)(NO3)2] (3-L1-3-L3), whereas complexation with sterically less hindered ligands, such as NH(CH2CH2N=CHC6H2-3-R1-5-R2-2-OH)2 (for L4H2, R1 = OMe and R2 = H; for L5H2, R1 = H and R2 = tBu; for L6H2, R1 = H and R2 = OMe; for L7H2, R1 = H and R2 = H; for L8H2, R1 = H and R2 = NO2; and for L9H2, R1 = tBu and R2 = NO2), afforded neutral dinuclear complexes [Ce(L4-9)(NO3)]2 (3-L4-3-L9). Among these newly prepared complexes, complex 3-L1 was selected as the best catalyst for oxidizing primary and secondary alcohols under a dioxygen atmosphere without any N-oxyl radicals such as TEMPO to produce the corresponding carbonyl compounds, where the oxo-bridged dinuclear complex worked as a catalyst while maintaining its dinuclear skeleton during the catalytic cycle. In addition, an intramolecular redox process between the two cerium centers through the bridging oxygen atom played a key role in forming the ligand phenoxide radical-mediated TEMPO-free alcohol oxidation reaction.
Novel pyridinedicarboxamide derivatives and a polymeric copper(II) complex: Synthesis, structural characterization, electrochemical behavior, catalytic and cytotoxic studies
Abdolmaleki, Sara,Ghadermazi, Mohammad
, p. 221 - 232 (2017)
Two new amide-based ligands, N,N′-bis(2-carboxylphenyl)-2,6-pyridinedicarboxamide (L1), N,N′-bis(2-carboxyphenyl ethyl ester)-2,6-pyridinedicarboxamide (L2) and a one-dimensional polymeric complex from reaction between (L1) and Cu(NO3)2·3H2O with the formula of {[Cu(CPCP)](DMAP)·3H2O}n [where DMAP is 4-dimethylaminopyridine and CPCP is 6-(2-carboxylatophenylcarbamoyl) picolinate] were synthesized. These compounds have been characterized spectroscopically and their molecular structures were determined by single-crystal X-ray diffraction. Also, thermal analysis (TGA/DTA) was carried out on complex (3). Possible mechanisms were proposed for esterification and hydrolysis of (L1). Study of electrochemical behavior of compounds using cyclic voltammetry at E of ?1.0 to +1.0?V showed two redox couple for complex (3) corresponding to Cu(I)/Cu(0) and Cu(II)/Cu(I) at E0′ of ?0.26 to 0.08?V versus Ag/AgCl. Ligands (L1) and (L2) did not exhibit any wave in the investigated potential range. Also, complex (3) was evaluated for catalytic activity on the oxidation of aromatic and aliphatic alcohols by changing parameters such as the amount of catalyst, oxidant and also reaction temperature. The outstanding catalytic performance of complex (3) was confirmed by selective conversion of alcohols to the corresponding aldehydes. The cytotoxic effect of compounds was evaluated using oxaliplatin as a positive control against MCF7 (a human breast cancer), HT29 (a human colon adenocarcinoma) and βTC (a mouse beta pancreatic) cell lines. The cancerous cells exhibited the highest sensitivity to compound (3) with IC50 values about 1–10?μM.
A new porous Co(ii)-metal-organic framework for high sorption selectivity and affinity to CO2and efficient catalytic oxidation of benzyl alcohols to benzaldehydes
Wu, Yun-Long,Yang, Rong-Rong,Yang, Guo-Ping,Yan, Yang-Tian,Su, Xiao-Lei,He, Xin-Hai,Song, Yan-Yan,Ma, Zheng-Sheng,Wang, Yao-Yu
, p. 3717 - 3723 (2021)
Herein, we report a new 3D porous Co(ii)-based metal-organic framework catalyst (Me2NH2)2[Co3(L)2(H2O)2]·2DMF (MOF I), which has been successfully prepared by using Co(ii) ions and rigid V-shaped 3,5-di(2,4-dicarboxylphenyl)pyridine (H4L) via the solvothermal reaction. Structural analysis reveals that I displays a porous structure with the pore size of 16.2 × 7.2 ?2 based on the trinuclear [Co3(COO)4(H2O)2N2] secondary building units (SBUs). Gas sorption experiments on the guest free sample I′ reveals a high capacity and selectivity to CO2 over CH4. And further, the catalytic explorations of the I′-catalyzed system (I′: 3 mol%; proline: 40 mol%; CH3CN: 2 mL) reveal that benzyl alcohols with different structures can be efficiently transformed into benzyl alcohols without by-products under mild conditions.
The effects of halogen substituents on the catalytic oxidation of benzyl-alcohols in the presence of dinuclear oxidovanadium(IV) complex
Bikas, Rahman,Shahmoradi, Elaheh,Noshiranzadeh, Nader,Emami, Marzieh,Reinoso, Santiago
, p. 100 - 109 (2017)
A new dinuclear complex of oxidovanadium(IV), namely [(VO)2(HL)(μ-O)] (1), has been synthesized by the reaction of VO(acac)2 with the heptadentate N4O3-donor Schiff base ligand, 2-(5-Bromo-2-hydroxyphenyl)-1,3-bis(2-(5-bromo-2-hydroxybenzylideneamino)ethyl)imidazolidine (H3L). The complex has been characterized by elemental analysis, spectroscopic methods and single-crystal X-ray diffraction. The latter technique revealed that the vanadium ions have distorted octahedral geometry and are connected together by oxido and phenolic oxygen atoms. The bridging oxido ligand shares the equatorial positions of the two metal centers while the oxygen atom of the bridging phenol group connects the axial positions. The catalytic activity of this complex has been tested for the oxidation of some benzyl alcohol derivatives by using H2O2 as a green oxidant. In order to maximize the yields, the effects of various influential parameters in catalytic reactions such as the oxidant-to-substrate molar ratio, the temperature and the solvent, were studied. Moreover, the electronic and steric effects of halogen substituents on the phenyl group of the substrate were also explored by analyzing the oxidation of benzyl alcohol derivatives with F, Cl and Br atoms in the relative para-position (electronic effect), and of another set of substrates with a Cl substituent in relative ortho-, meta, and para-positions (steric effect). The results of these catalytic studies show that complex 1 catalyzes the oxidation of benzyl alcohol derivatives to the corresponding benzaldehydes with little amounts of the benzoic acid being detectable in the reaction mixture. Both the reaction conditions and the substituents on the phenyl group of the benzyl alcohols affect the selectivity and the activity of this catalytic system.
Lead-free perovskite Cs3Bi2Br9 heterojunctions for highly efficient and selective photocatalysis under mild conditions
He, Jing-Hui,Li, Lanxin,Lu, Jian-Mei,Sun, Qimeng,Wang, Jia,Wei, Jialiang,Ye, Wen
, (2021/10/27)
Lead halide perovskites possess excellent photoelectric properties and are promising for photocatalysis. However, the toxicity of lead in these perovskites has hindered their application. We designed a stable, lead-free heterojunction to enhance the photocatalytic efficiency of the perovskite. A production rate of 1465 μmol/g/h for the selective oxidation of benzyl alcohol was achieved, which was the highest among all inorganic catalysts without zero-valent metal cocatalyst in the atmosphere at room temperature. In addition, the heterojunction degraded 74.7% of 10 ppm 2-mercaptobenzothiazole within 10 min, and achieving a final degradation rate exceeding 99.9% in 20 min, which is the best degradation efficiency among all reported studies. Detailed optical characterisation proved that the high efficiency stems from band matching and charge transfer between Cs3Bi2Br9 and TiO2. This result will inspire the design of additional lead-free perovskites for photocatalysis.
Lithioarene Cycliacylation and Pd-Catalyzed Aminoethylation/Cyclization to Access Electronically Diverse Saturated Isoquinoline Derivatives
Altenbach, Robert J.,Buchman, Marek,Farney, Elliot P.,Gfesser, Gregory A.,Greszler, Stephen N.,Voight, Eric A.
, p. 776 - 789 (2022/01/14)
We report operationally facile methods for the synthesis of substituted dihydroisoquinolinones and tetrahydroisoquinolines from readily accessible o-bromobenzyl bromides and o-bromobenzaldehydes, respectively. While classical electrophilic aromatic substitution reactions are tailored to the construction of saturated isoquinolines derived from electron-rich precursors, we demonstrate efficient syntheses from electronically diverse substrates to produce cyclized products as single regioisomers.
The dehydrogenative oxidation of aryl methanols using an oxygen bridged [Cu-O-Se] bimetallic catalyst
Choudhury, Prabhupada,Behera, Pradyota Kumar,Bisoyi, Tanmayee,Sahu, Santosh Kumar,Sahu, Rashmi Ranjan,Prusty, Smruti Ranjita,Stitgen, Abigail,Scanlon, Joseph,Kar, Manoranjan,Rout, Laxmidhar
supporting information, p. 5775 - 5779 (2021/04/12)
Herein, we report a new protocol for the dehydrogenative oxidation of aryl methanols using the cheap and commercially available catalyst CuSeO3·2H2O. Oxygen-bridged [Cu-O-Se] bimetallic catalysts are not only less expensive than other catalysts used for the dehydrogenative oxidation of aryl alcohols, but they are also effective under mild conditions and at low concentrations. The title reaction proceeds with a variety of aromatic and heteroaromatic methanol examples, obtaining the corresponding carbonyls in high yields. This is the first example using an oxygen-bridged copper-based bimetallic catalyst [Cu-O-Se] for dehydrogenative benzylic oxidation. Computational DFT studies reveal simultaneous H-transfer and Cu-O bond breaking, with a transition-state barrier height of 29.3 kcal mol?1
Fe(III) superoxide radicals in halloysite nanotubes for visible-light-assisted benzyl alcohol oxidation and oxidative C[sbnd]C coupling of 2-naphthol
Bania, Kusum K.,Baruah, Manash J.,Bora, Tonmoy J.,Dutta, Rupjyoti,Guha, Ankur Kanti,Roy, Subhasish
, (2021/09/20)
Selective oxidation of benzyl alcohols to aldehydes and 2-naphthol to BINOL was achieved by activation of molecular oxygen (O2) and hydrogen peroxide (H2O2) over an iron-oxide catalyst embedded in halloysite nanotube. Electron spin resonance spectroscopy (ESR), Raman and in situ FTIR spectroscopic analysis provided direct evidence for the involvement of superoxide radical bound FeIII species in the oxidation reaction. Both the analysis suggested the end-on binding of superoxide radical with FeIII-centre. The stability of such radical bound FeIII-species in halloysite nanotube was analyzed through density functional theory (DFT) calculations. Results suggested that end-on (η1) binding was favourable by 13.5 kcal/ mol than the side-on (η2) binding mode. The formation of such reactive species was believed to play the crucial role in bringing the high selectivity in the catalytic oxidation of benzyl alcohol and oxidative C[sbnd]C coupling of 2-naphthol. UV–Vis spectroscopic studies on the oxidation of benzyl alcohol suggested for the initial adsorption of substrate molecule on the catalyst surface followed by its interaction with FeIII -superoxide/hydroperoxide species generated upon photoirradiation with visible light in presence of O2. The presence of a suitable band gap ～2.14 eV enabled the catalyst to catalyze the reaction under visible light irradiation. Both the reactions (benzyl alcohol and 2-naphthol oxidation) were tested in presence of both O2 and H2O2 as oxidants at ambient temperature. The influence of different parameters like rate of oxygen flow, amount of peroxide, nature of solvent, and catalyst amount on the conversion and selectivity of the reactions were studied to understand their role in the catalytic reactions. Successful oxidation of 2-naphthol with H2O2 as oxidant was a real success to overcome the limitations associated with this reaction using H2O2 as oxidant.
An aerobic oxidation of alcohols into carbonyl synthons using bipyridyl-cinchona based palladium catalyst
Cheedarala, Ravi Kumar,Chidambaram, Ramasamy R.,Siva, Ayyanar,Song, Jung Il
, p. 32942 - 32954 (2021/12/02)
We have reported an aerobic oxidation of primary and secondary alcohols to respective aldehydes and ketones using a bipyridyl-cinchona alkaloid based palladium catalytic system (PdAc-5) using oxygen at moderate pressure. ThePdAc-5catalyst was analysed using SEM, EDAX, and XPS analysis. The above catalytic system is used in experiments for different oxidation systems which include different solvents, additives, and bases which are cheap, robust, non-toxic, and commercially available on the industrial bench. The obtained products are quite appreciable in both yield and selectivity (70-85%). In addition, numerous important studies, such as comparisons with various commercial catalysts, solvent systems, mixture of solvents, and catalyst mole%, were conducted usingPdAc-5. The synthetic strategy of oxidation of alcohol into carbonyl compounds was well established and all the products were analysed using1H NMR,13CNMR and GC-mass analyses.
Cerium-photocatalyzed aerobic oxidation of benzylic alcohols to aldehydes and ketones
K?nig, Burkhard,Kumar, Sumit,Stahl, Jessica,Yatham, Veera Reddy,Yedase, Girish Suresh
supporting information, p. 1727 - 1732 (2021/08/05)
We have developed a cerium-photocatalyzed aerobic oxidation of primary and secondary benzylic alcohols to aldehydes and ketones using inexpensive CeCl3 7H2O as photocatalyst and air oxygen as the terminal oxidant.
