- Pd nanoparticles supported on pyrazolone-functionalized hollow mesoporous silica as an excellent heterogeneous nanocatalyst for the selective oxidation of benzyl alcohol
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Hollow mesoporous silica nanoparticles (HMSNs), by exploiting both their organo-functionalized surface and porous shell were chosen as the ideal support for the immobilization of palladium nanoparticles (Pd-NPs). The HMSNs were created by acidic removal of Fe3O4 nanoparticles from silica-coated Fe3O4 core-shell. The catalyst was prepared following surface modification of HMSNs by (3-chloropropyl)-triethoxysilane (CPTES), functionalization by pyrazolone-based ligand, and stabilization of Pd-NPs on HMSNs. The resulting catalyst was fully characterized by different analytical techniques. This new heterogeneous catalyst showed high catalytic activity and excellent selectivity in the selective oxidation of benzyl alcohols in ethanol at ambient temperature. Easy separation by centrifuge and reusability for five successive cycles without significant loss of catalytic activity were some advantages of this catalyst.
- Ghorbani, Somayeh,Parnian, Rouhallah,Soleimani, Ebrahim
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Read Online
- Polyoxotungstate ([PW11O39]7-) immobilized on mesoporous polymer for selective liquid-phase oxidation of alcohols using H2O2
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Selective oxidation of alcohols is an attractive organic transformation and has received tremendous attention from the scientific community over the years. Herein, a mesoporous polymer (MP) was synthesized by a template-free solvothermal approach. The surface of the MP was functionalized with quaternary ammonium groups and polyoxotungstate anion (PW11O397-) was subsequently supported on the MP as a counter anion to the ammonium cation by a simple ion-exchange procedure. The structure of PW11 and PW4 complexes was confirmed by 31P NMR and FTIR analysis. The surface properties of all the catalysts synthesized were explored by various characterization techniques such as nitrogen sorption, TGA, contact angle measurement, and ICP-OES analysis. The synthesized PW11/MP catalysts were employed for selective oxidation of alcohols. Among the various PW11 supported catalysts, PW11/MP (80 : 20) demonstrated excellent catalytic activity for the oxidation of alcohols using aqueous H2O2. The PW11/MP (80 : 20) catalyst showed good catalytic activity for oxidation of a wide range of alcohols including substituted, heterocyclic and secondary alcohols. The superior catalytic activity of PW11/MP (80 : 20) is attributed to an optimum balance in the hydrophilicity/hydrophobicity in the mesoporous environment, better catalyst wettability, and enrichment of reactants in the catalytic active sites.
- Choudhuri, Jyoti Roy,Churipard, Sathyapal R.,Kanakikodi, Kempanna S.,Maradur, Sanjeev P.
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Read Online
- V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
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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.
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p. 3594 - 3600
(2021/07/02)
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- Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO4nanoparticles
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Visible light-mediated selective and efficient oxidation of various primary/secondary benzyl alcohols to aldehydes/ketones and oxidative dehydrogenation (ODH) of partially saturated heterocycles using a scalable and reusable heterogeneous photoredox catalyst in aqueous medium are described. A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential oxidation of benzyl alcohols and heteroaryl carbinols followed by the Pictet-Spengler cyclization and then aromatization to obtain the β-carbolines in high isolated yields. This methodology was found to be suitable for scale up and reusability. To the best of our knowledge, this is the first report on the oxidation of structurally diverse aryl carbinols and ODH of partially saturated N-heterocycles using a recyclable and heterogeneous photoredox catalyst under environmentally friendly conditions.
- Abinaya, R.,Balasubramaniam, K. K.,Baskar, B.,Divya, P.,Mani Rahulan, K.,Rahman, Abdul,Sridhar, R.,Srinath, S.
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p. 5990 - 6007
(2021/08/24)
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- Preparation method of m-phenoxy benzaldehyde
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The invention provides a preparation method of m-phenoxy benzaldehyde, and belongs to the technical field of synthesis of medical intermediates. The preparation method comprises the following steps: mixing m-cresol, halogenated benzene, inorganic base and a catalyst for condensation reaction to obtain m-phenoxy toluene; mixing the m-phenoxy toluene with an oxidant, and carrying out an oxidation reaction under acidic conditions to obtain m-phenoxy benzaldehyde. According to the preparation method, m-cresol and halogenated benzene are taken as raw materials, the cost of the raw materials is low, m-phenoxy toluene is firstly prepared through a condensation reaction, then m-phenoxy toluene is oxidized into m-phenoxy benzaldehyde, the yield of the product is high, and the preparation is simple. The result of the embodiment shows that the yield of the m-phenoxybenzaldehyde prepared by the method is 56.8% or above.
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Paragraph 0044-0046; 0048-0053; 0055-0056; 0058-0059; 0061
(2021/04/17)
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- Preparation method of m-phenoxy benzaldehyde
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The invention provides a preparation method of m-phenoxy benzaldehyde, and belongs to the technical field of organic synthesis. The preparation method provided by the invention comprises the following steps: condensing m-cresol serving as a raw material with halogenated benzene to obtain m-phenoxytoluene, reacting the m-phenoxytoluene with chlorine to chloridize methyl to obtain a m-phenoxytoluene chloro product, oxidizing the m-phenoxytoluene chloro product through Komblum to obtain an oxide of the m-phenoxytoluene chloro product, and directly hydrolyzing the m-phenoxytoluene chloro product without separation to obtain the product m-phenoxy benzaldehyde. The preparation method provided by the invention has the advantages that the raw materials are cheap and easily available, the yield is high, the product quality meets the market demand, the problems of high raw material price, many side reactions, many impurities, low yield, large wastewater amount and serious environmental pollution in the traditional process are solved, and the production cost of m-phenoxybenzaldehyde is greatly reduced. Data of the embodiment shows that the total yield of m-phenoxybenzaldehyde obtained by the preparation method provided by the invention is 83.5%, and the gas phase content is 99.3%.
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Paragraph 0034; 0059; 0061-0067; 0069-0075; 0077-0080; 0082
(2021/04/28)
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- Preparation method of m-phenoxy benzaldehyde
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The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of m-phenoxy benzaldehyde. According to the preparation method provided by the invention, m-hydroxybenzaldehyde is salified by phenolic hydroxyl under an alkaline anhydrous condition, and then is subjected to substitution reaction with halobenzene to obtain m-phenoxy benzaldehyde, so that disproportionation reaction of aldehyde groups during reaction in an alkaline aqueous solution is avoided, the utilization rate of raw materials is increased, and side reactions are reduced. The purification of the m-phenoxybenzaldehyde product and the improvement of the yield are facilitated. The test result of the embodiment shows that the yield of m-phenoxybenzaldehyde obtained by the preparation method provided by the invention is 79.9-81%, and the yield is high; the gas phase content of m-phenoxy benzaldehyde is 98.9%-99.3%, and the purity of m-phenoxy benzaldehyde is high.
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Paragraph 0055-0076; 0081-0088
(2021/04/17)
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- A Simple and Effective Method for Catalytic Oxidation of Alcohols Using the Oxone/Bu4NHSO4 Oxidation System
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Abstract: A simple and efficient procedure is reported for the oxidation of alcohols tocarbonyl compounds with Oxone (potassium peroxymonosulfate) in the presence oftetrabutylammonium hydrogen sulfate as catalyst with excellent conversion andhigh selectivity using chloroform as solvent at room temperature. The efficiencyof several phase-transfer catalysts in the oxidation of benzyl alcohols andbenzydrol was studied. The proposed catalytic system was also evaluated in theoxidation of alcohols in water at room temperature.
- An, X. Q.,Kang, M.,Ma, H. C.,Yang, Y. X.,Yang, Z. W.,Zeng, W.
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p. 521 - 523
(2020/04/29)
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- KMnO4-catalyzed chemoselective deprotection of acetate and controllable deacetylation-oxidation in one pot
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A novel and efficient protocol for chemoselective deacetylation under ambient conditions was developed using catalytic KMnO4. The stoichiometric use of KMnO4 highlighted the dual role of a heterogeneous oxidant enabling direct access to aromatic aldehydes in one-pot sequential deacetylation-oxidation. The reaction employed an alternative solvent system and allowed the clean transformation of benzyl acetate to sensitive aldehyde in a single step while preventing over-oxidation to acids. Use of inexpensive and readily accessible KMnO4 as an environmentally benign reagent and the ease of the reaction operation were particularly attractive, and enabled the controlled oxidation and facile cleavage of acetate in a preceding step. This journal is
- Gurawa, Aakanksha,Kumar, Manoj,Rao, Dodla S.,Kashyap, Sudhir
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p. 16702 - 16707
(2020/10/27)
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- Clean and Selective Oxidation of Alcohols with Oxone and Phase-Transfer Catalysts in Water
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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.
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p. 1790 - 1794
(2020/12/01)
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- Development of novel phenoxy-diketopiperazine-type plinabulin derivatives as potent antimicrotubule agents based on the co-crystal structure
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The co-crystal structure of Compound 6b with tubulin was prepared and solved for indicating the binding mode and for further optimization. Based on the co-crystal structures of tubulin with plinabulin and Compound 6b, a total of 27 novel A/B/C-rings plinabulin derivatives were designed and synthesized. Their biological activities were evaluated against human lung cancer NCI-H460 cell line. The optimum phenoxy-diketopiperazine-type Compound 6o exhibited high potent cytotoxicity (IC50 = 4.0 nM) through SAR study of three series of derivatives, which was more potent than plinabulin (IC50 = 26.2 nM) and similar to Compound 6b (IC50 = 3.8 nM) against human lung cancer NCI-H460 cell line. Subsequently, the Compound 6o was evaluated against other four human cancer cell lines. Both tubulin polymerization assay and immunofluorescence assay showed that Compound 6o could inhibit microtubule polymerization efficiently. Furthermore, theoretical calculation of the physical properties and molecular docking were elucidated for these plinabulin derivatives. The binding mode of Compound 6o was similar to Compound 6b based on the result of molecular docking. The theoretical calculated LogPo/w and PCaco of Compound 6o were better than Compound 6b, which could enhance its cytostatic activity. Therefore, Compound 6o might be developed as a novel potent anti-microtubule agent.
- Ding, Zhongpeng,Ma, Mingxu,Zhong, Changjiang,Wang, Shixiao,Fu, Zhangyu,Hou, Yingwei,Liu, Yuqian,Zhong, Lili,Chu, Yanyan,Li, Feng,Song, Cai,Wang, Yuxi,Yang, Jinliang,Li, Wenbao
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- Cinnamonitrile adjuvants restore susceptibility to β-lactams against methicillin-resistant staphylococcus aureus
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β-Lactams are used routinely to treat Staphylococcus aureus infections. However, the emergence of methicillin-resistant S. aureus (MRSA) renders them clinically precarious. We describe a class of cinnamonitrile adjuvants that restore the activity of oxacillin (a penicillin member of the β-lactams) against MRSA. The lead adjuvants were tested against six important strains of MRSA, one vancomycin-intermediate S. aureus (VISA) strain, and one linezolid-resistant S. aureus strain. Five compounds out of 84 total compounds showed broad potentiation. At 8 μM (E)-3-(5-(3,4-dichlorobenzyl)-2-(trifluoromethoxy)phenyl)-2-(methylsulfonyl)acrylonitrile (26) potentiated oxacillin with a >4000-fold reduction of its MIC (from 256 to 0.06 mg·L-1). This class of adjuvants holds promise for reversal of the resistance phenotype of MRSA.
- Speri, Enrico,Kim, Choon,De Benedetti, Stefania,Qian, Yuanyuan,Lastochkin, Elena,Fishovitz, Jennifer,Fisher, Jed F.,Mobashery, Shahriar
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p. 1148 - 1153
(2019/08/27)
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- MgBr2 supported on Fe3O4@SiO2?~?urea nanoparticle: An efficient catalyst for ortho-formylation of phenols and oxidation of benzylic alcohols
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Urea was successfully immobilized on the surface of chloropropyl-modified Fe3O4@SiO2 core–shell magnetic nanoparticles, then supported by MgBr2 and acts as a unique catalyst for oxidation of benzylic alcohols to aldehydes and ketones, and ortho-formylation of phenols to salicylaldehydes. The prepared catalyst was characterized by FT-IR, transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, dispersive X-ray spectroscopy, CHN and TGA. It was found that Fe3O4@SiO2?~?urea/MgBr2 showed higher catalytic activity than homogenous MgBr2, and could be reused several times without significant loss of activity.
- Soleimani, Ebrahim,Yaesoobi, Nadieh,Ghasempour, Hamid Reza
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- Correlation analysis of reactivity in the oxidation of substituted benzyl alcohols by benzimidazolium dichromate - A kinetic and mechanistic aspects
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The oxidation of a number of para- and meta-substituted benzyl alcohols by benzimidazolium dichromate (BIDC), in dimethyl sulphoxide, leads to the formation of the corresponding benzaldehydes. The reaction is first order with respect to each BIDC and alcohol. The reaction is catalyzed by hydrogen ions and the dependence has the form kobs = a + b[H+]. The oxidation of [1,1-2H2]benzyl alcohol exhibited the presence of a substantial kinetic isotope effect. The rates of the oxidation of meta-substituted benzyl alcohols correlated best with Taft's σ1 and σR0 constants. The para-substituted compounds exhibited excellent correlation with σ1 and σRBA values. The polar reaction constants are negative. The rate of oxidation of benzyl alcohol was determined in nineteen organic solvents. An analysis of the solvent effect by multiparametric equations indicated the greater importance of the cation-solvating power of the solvents. Suitable mechanisms have been discussed.
- Kumar, Pravesh,Panday, Dinesh,Kothari, Seema
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p. 1207 - 1215
(2020/06/27)
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- Tungstate ions (WO4 =) supported on imidazolium framework as novel and recyclable catalyst for rapid and selective oxidation of benzyl alcohols in the presence of hydrogen peroxide
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Tungstate salt with imidazolium framework is found to be a recoverable and heterogeneous system favouring the highly selective oxidation of primary benzylic alcohols to corresponding aldehydes with 30% H2O2 as a green oxidant under neutral aqueous reaction conditions. Furthermore, in order to demonstrate the recyclability of the catalyst, it was recovered and efficiently reused in seven succeeding reaction cycles without any significant loss. The use of green solvent, very short reaction time with excellent yields and recyclability of the catalyst make this protocol highly advantageous.
- Hosseini Eshbala, Fereshteh,Mohanazadeh, Farajollah,Sedrpoushan, Alireza
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- Transition State-Based Sialyltransferase Inhibitors: Mimicking Oxocarbenium Ion by Simple Amide
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In the new transition-state based sialyltransferase inhibitors, an amide group was placed at the corresponding C-2 position of CMP-sialic acid to mimic the geometry and charge distribution in the transition state, and simple aromatic or aliphatic rings were used instead of the sialic acid moiety. All synthetic compounds exhibited excellent α(2-6)-sialyltransferase inhibition, resulting in up to a 2600-fold higher affinity for the enzyme than CMP-Neu5Ac, suggesting that amide is a key element for simulating transition-state features.
- Guo, Jian,Li, Wenming,Xue, Weiwei,Ye, Xin-Shan
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supporting information
p. 2135 - 2141
(2017/03/17)
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- One-pot two-step conversion of aromatic carboxylic acids and esters to aromatic aldehydes via indium-catalyzed reductive thioacetalization and desulfurization
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Described herein is that a new approach to a one-pot two-step conversion of aromatic carboxylic acids/esters to aromatic aldehydes, in which indium(III) iodide effectively catalyzes both the first reductive thioacetalization of carboxylic acids and a subsequent desulfurization of the in-situ formed thioacetal intermediates leading to aldehydes.
- Sakai, Norio,Minato, Kohei,Ogiwara, Yohei
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supporting information
p. 4563 - 4567
(2017/11/03)
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- Indium(III) Isopropoxide as a Hydrogen Transfer Catalyst for Conversion of Benzylic Alcohols into Aldehydes or Ketones via Oppenauer Oxidation
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Indium(III) isopropoxide [In(Oi-Pr)3] was applicable as an Oppenauer oxidation catalyst, and the conversion of primary or secondary alcohols into the corresponding aldehydes or ketones was promoted at room temperature using pivalaldehyde as an oxidant.
- Ogiwara, Yohei,Ono, Yuji,Sakai, Norio
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p. 4143 - 4148
(2016/11/26)
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- Screening of by-products of esfenvalerate in aqueous medium using SBSE probe desorption GC-IT-MS technique
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The pyrethroids, their metabolites and by-products have been recognized as toxic to environment and human health. Despite several studies about esfenvalerate toxicity and its detection in water and sediments, information about its degradation products is still scanty. In this work, esfenvalerate degradation products were obtained by chemical oxidation with hydrogen peroxide and their structure was elucidated using a procedure known as stir bar sorptive extraction (SBSE) probe desorption gas chromatography-ion trap mass spectrometry (GC-IT-MS) analysis. This procedure consists of the thermal desorption of analytes extracted from a SBSE stir bar introduced by a probe into a gas chromatograph (GC) coupled to an ion trap mass spectrometry (IT-MS) system. Based on IT-MS data, a degradation pathway of esfenvalerate is proposed with ten products of chemical oxidation of esfenvalerate that are fully identified. Among these compounds, 3-phenoxybenzoic acid and 3-phenoxybenzaldehyde were detected, reported as being environmental metabolites of some pyrethroids, with endocrine-disrupting activity.
- Colombo, Renata,Ferreira, Tanare C. R.,Yariwake, Janete H.,Lanza, Marcos R. V.
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p. 1831 - 1837
(2015/09/22)
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- A counteranion triggered arylation strategy using diaryliodonium fluorides
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A mild and transition metal-free counteranion triggered arylation strategy has been developed using diaryliodonium fluorides. The fluoride counteranion within the hypervalent iodonium species displays unusual reactivity that activates a phenolic O-H bond leading to electrophilic O-arylation. A wide range of phenols and diaryliodonium salts are compatible with this transformation under remarkably mild conditions. Furthermore, we pre-empt the wider implications of this strategy by demonstrating the compatibility of the arylation tactic with latent carbon nucleophiles.
- Chan,McNally,Toh,Mendoza,Gaunt
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p. 1277 - 1281
(2015/02/05)
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- Practical organic solvent-free Cu(OAc)2/DMAP/TEMPO-catalyzed aldehyde and imine formation from alcohols under air atmosphere
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A highly efficient and practical organic solvent-free Cu(OAc)2/DMAP/TEMPO catalyst system for the selective aerobic oxidation of benzylic and allylic alcohols to aldehydes and phenones under an ambient air atmosphere was reported. A wide range of functional groups such as phenolic hydroxyl, amino, and methylthio are compatible with the catalyst system. The organic solvent-free aerobic oxidative imine synthesis from benzyl alcohol and amines was also achieved via the newly developed Cu(OAc)2/DMAP/TEMPO catalyst. 100 g-scale reactions for aldehyde and imine formation were achieved with over 90% yield using 0.5 mol% catalyst loading in 36 hours, presenting a potential valuable protocol for both economical and environmental considerations. This journal is
- Guan, Mingyu,Wang, Chao,Zhang, Jingyu,Zhao, Yingsheng
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p. 48777 - 48782
(2014/12/10)
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- Biopolymer-metal complex wool-Pd: An efficient and reusable heterogeneous catalyst for the heck cross-coupling reactions and aerobic oxidation of alcohols in aqueous media
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Heterogeneous palladium catalysts, which are supported by biopolymer, have been applied in water-mediated Heck and the oxidation of alcohols cyclic reaction without assistance of any phosphine ligands. More importantly, owing to the interconversion between the Pd0 and PdII oxidation states during the Heck and oxidation reaction course, the catalyst exhibits good activity in Heck cross-coupling reaction of bromobenzene with styrene and oxidation reaction of alcohols to corresponding aldehydes or ketones without overoxidation using air as the source of molecular oxygen. This heterogeneous wool-Pd catalyst is stable, shows negligible metal leaching, and can be reused several times in reactions without significant loss of activity and selectivity.
- Wu, Shang,Zhang, Hong,Wang, Yanbin,Su, Qiong,Lei, Ziqiang,Wu, Lan
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p. 774 - 779
(2015/04/14)
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- Practical Cu(OAc)2/TEMPO-catalyzed selective aerobic alcohol oxidation under ambient conditions in aqueous acetonitrile
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We reported a ligand-and additive-free Cu(OAc)2/TEMPO catalyst system that enables efficient and selective aerobic oxidation of a broad range of primary and secondary benzylic alcohols, primary and secondary 1-heteroaryl alcohols, cinnamyl alcohols, and aliphatic alcohols to the corresponding aldehydes and ketones. This ambient temperature oxidation protocol is of practical features like aqueous acetonitrile as solvent, ambient air as the terminal oxidant, and low catalyst loading, presenting a potential value in terms of both economical and environmental considerations. Based on the experimental observations, a plausible reaction mechanism was proposed.
- Jiang, Jian-An,Du, Jia-Lei,Wang, Zhan-Guo,Zhang, Zhong-Nan,Xu, Xi,Zheng, Gan-Lin,Ji, Ya-Fei
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supporting information
p. 1677 - 1681
(2014/03/21)
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- Magnetic copper ferrite nanoparticles/TEMPO catalyzed selective oxidation of activated alcohols to aldehydes under ligand- and base-free conditions in water
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A novel, effective and sustainable strategy for the synthesis of aldehydes has been developed using inexpensive, readily available, oxygen-stable and recyclable CuFe2O4 nanoparticles as the catalyst. The corresponding substituted aldehydes were obtained in moderate to good yields by aerobic oxidation of aromatic alcohols in water under dioxygen atmosphere. Importantly, a ligand or a base was not necessary. The catalyst was completely recoverable with an external magnet and could be reused six times without significant loss of catalytic activity.
- Zhu, Xiao,Yang, Daoshan,Wei, Wei,Jiang, Min,Li, Lulu,Zhu, Xiangbing,You, Jinmao,Wang, Hua
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p. 64930 - 64935
(2015/04/27)
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- Magnetically retrievable MFe2O4 spinel (M = Mn, Co, Cu, Ni, Zn) catalysts for oxidation of benzylic alcohols to carbonyls
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The catalytic activity of the MFe2O4 spinel (M = Mn, Co, Cu, Ni, Zn) was investigated for the oxidation of benzylic alcohols to respective carbonyls using tert-butyl hydroperoxide (TBHP) as an oxidant. The combination of CoFe2O4/TBHP in a dimethyl sulfoxide (DMSO) catalytic system was found to be most efficient for this catalytic conversion. A CoFe2O4 catalyst is magnetically separable and could be reused with no considerable loss in catalytic activity as proved for 5 consecutive cycles.
- Burange, Anand S.,Kale, Sandip R.,Zboril, Radek,Gawande, Manoj B.,Jayaram, Radha V.
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p. 6597 - 6601
(2014/02/14)
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- Fenpropathrin biodegradation pathway in bacillus sp. DG-02 and its potential for bioremediation of pyrethroid-contaminated soils
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The widely used insecticide fenpropathrin in agriculture has become a public concern because of its heavy environmental contamination and toxic effects on mammals, yet little is known about the kinetic and metabolic behaviors of this pesticide. This study reports the degradation kinetics and metabolic pathway of fenpropathrin in Bacillus sp. DG-02, previously isolated from the pyrethroid-manufacturing wastewater treatment system. Up to 93.3% of 50 mg L-1 fenpropathrin was degraded by Bacillus sp. DG-02 within 72 h, and the degradation rate parameters qmax, Ks, and K i were determined to be 0.05 h-1, 9.0 mg L-1, and 694.8 mg L-1, respectively. Analysis of the degradation products by gas chromatography-mass spectrometry led to identification of seven metabolites of fenpropathrin, which suggest that fenpropathrin could be degraded first by cleavage of its carboxylester linkage and diaryl bond, followed by degradation of the aromatic ring and subsequent metabolism. In addition to degradation of fenpropathrin, this strain was also found to be capable of degrading a wide range of synthetic pyrethroids including deltamethrin, λ-cyhalothrin, β-cypermethrin, β-cyfluthrin, bifenthrin, and permethrin, which are also widely used insecticides with environmental contamination problems with the degradation process following the first-order kinetic model. Bioaugmentation of fenpropathrin-contaminated soils with strain DG-02 significantly enhanced the disappearance rate of fenpropathrin, and its half-life was sharply reduced in the soils. Taken together, these results depict the biodegradation mechanisms of fenpropathrin and also highlight the promising potentials of Bacillus sp. DG-02 in bioremediation of pyrethroid-contaminated soils.
- Chen, Shaohua,Chang, Changqing,Deng, Yinyue,An, Shuwen,Dong, Yi Hu,Zhou, Jianuan,Hu, Meiying,Zhong, Guohua,Zhang, Lian-Hui
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p. 2147 - 2157
(2014/04/03)
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- Novel [4-hydroxy-TEMPO + NaCl]/SiOas a reusable catalyst for aerobic oxidation of alcohols to carbonyls
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A convenient method for the preparation of [4-hydroxy-TEMPO + NaCl]/SiOwas developed. And [4-hydroxy-TEMPO + NaCl]/SiOwith Fe(NOH was used for an aerobic oxidation of alcohols to carbonyls under mild reaction conditions. Alcohols were converted to the corresponding carbonyls in good to excellent yields. [4-Hydroxy-TEMPO + NaCl]/SiOcan be easily separated from the reaction mixture by filtration and reused at least six times. Georg Thieme Verlag Stuttgart · New York.
- Tamura, Naoya,Aoyama, Tadashi,Takido, Toshio,Kodomari, Mitsuo
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experimental part
p. 1397 - 1401
(2012/07/03)
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- Metal-free arylation of oxygen nucleophiles with diaryliodonium salts
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Phenols and carboxylic acids are efficiently arylated with diaryliodonium salts. The reaction conditions are mild, metal free, and avoid the use of halogenated solvents, additives, and excess reagents. The products are obtained in good-to-excellent yields after short reaction times. Steric hindrance is very well tolerated, both in the nucleophile and diaryliodonium salt. The scope includes ortho- and halo-substituted products, which are difficult to obtain by metal-catalyzed protocols. Many functional groups are tolerated, including carbonyl groups, heteroatoms, and alkenes. Unsymmetric salts can be chemoselectively utilized to obtain products with hitherto unreported levels of steric congestion. The arylation has been extended to sulfonic acids, which can be converted to sulfonate esters by two different approaches. With recent advances in efficient synthetic procedures for diaryliodonium salts the reagents are now inexpensive and readily available. The iodoarene byproduct formed from the iodonium reagent can be recovered quantitatively and used to regenerate the diaryliodonium salt, which improves the atom economy. Copyright
- Jalalian, Nazli,Petersen, Tue B.,Olofsson, Berit
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supporting information
p. 14140 - 14149,10
(2012/12/12)
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- Solvent-free selective oxidation of primary alcohols-to-aldehydes and aldehydes-to-carboxylic acids by molecular oxygen over MgO-supported nano-gold catalyst
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Magnesium oxide supported nano-gold catalyst (prepared by the homogeneous deposition precipitation technique) showed high activity/selectivity and excellent reusability in the oxidation of different primary alcohols and aldehydes to corresponding aldehydes and carboxylic acids, respectively, by molecular oxygen (under atmospheric pressure) in the absence of any solvent. Influence of the catalyst calcination temperature (400-900 °C), reaction temperature (50-120 °C) and use of different solvents (viz. toluene, p-xylene, DMF or DMSO) on the oxidation reaction has also been studied.
- Choudhary, Vasant R.,Dumbre, Deepa K.
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experimental part
p. 82 - 86
(2012/06/01)
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- Room temperature, metal-free synthesis of diaryl ethers with use of diaryliodonium salts
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A fast, high-yielding synthesis of diaryl ethers with use of mild and metal-free conditions has been developed. The scope includes bulky ortho-substituted diaryl ethers, which are difficult to obtain by metal-catalyzed protocols. Halo-substituents, racemization-prone amino acid derivatives, and heteroaromatics are also tolerated. The methodology is expected to be of high utility in the synthesis of complex molecules and in the pharmaceutical industry.
- Jalalian, Nazli,Ishikawa, Eloisa E.,Silva, Luiz F.,Olofsson, Berit
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supporting information; experimental part
p. 1552 - 1555
(2011/04/26)
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- A nitric acid-assisted carbon-catalyzed oxidation system with nitroxide radical cocatalysts as an efficient and green protocol for selective aerobic oxidation of alcohols
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The incorporation of nitroxide radicals into a nitric acid-assisted carbon-catalyzed oxidation system (NACOS) afforded a highly efficient, widely applicable, non-metallic approach for the selective aerobic oxidations of alcohols. Without any solvent, this novel protocol has the ability to oxidize various primary alcohols to their corresponding aldehydes with selectvities as high as 99% at full conversions, with only 0.1 mol% of nitroxide radicals and 4.5 wt% of activated carbon under mild conditions (temperatures as low as 50°C and atmospheric pressure). The performances of several stable nitroxide radicals have been compared. The effects of nitric acid concentration, activated carbon loading, and temperature have been studied for the oxidation of benzyl alcohol. The enhanced NACOS represents a greener and more efficient fundamental chemical process, due to its use of molecular oxygen as an oxidant, and its solvent-free nature.
- Kuang, Yongbo,Rokubuichi, Hodaka,Nabae, Yuta,Hayakawa, Teruaki,Kakimoto, Masa-Aki
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experimental part
p. 2635 - 2642
(2010/12/25)
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- TEMPO/HCl/NaNO2 catalyst: A transition-metal-free approach to efficient aerobic oxidation of alcohols to aldehydes and ketones under mild conditions
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Hydrochloric acid, a very inexpensive and readily available inorganic acid, has been found to cooperate exquisitely with NaNO2/TEMPO in catalyzing the molecular-oxygen-driven oxidation of a broad range of alcohol substrates to the corresponding aldehydes and ketones. This transition-metal- free catalytic oxidative conversion is novel and represents an interesting alternative route to the corresponding carbonyl compounds to the metal-catalyzed aerobic oxidation of alcohols.The reaction is highly selective with respect to the desired product when carried out at room temperature in air at atmospheric pressure. Notably, the use of very inexpensive NaNO2 and HCl in combination with TEMPO for this highly selective aerobic oxidation of alcohols in air at ambient temperaturemakes the reaction operationally and economically very attractive. The results of mechanistic studies, performed with the aid of electrospray ionization mass spectrometry (ESI-MS), are presented and discussed. TEMPO, TEMPOH, and TEMPO+ were observed in the redox cycle by means of ESI-MS. On the basis of these observations, a mechanism is proposed that may provide an insight into the newly developed aerobic alcohol oxidation.
- Wang, Xinliang,Liu, Renhua,Jin, Yu,Liang, Xinmiao
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supporting information; experimental part
p. 2679 - 2685
(2009/04/10)
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- PHAMACEUTICAL PREPARATIONS COMPRISING INSULIN
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Novel preparations comprising ligands for the HisB10 Zn2+ sites of the R-state insulin hexamer wherein the ligand is extended by protamine that are capable of prolonging the ac-tion of insulin preparations.
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Page/Page column 122
(2010/02/15)
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- A high-throughput screening assay for hydroxynitrile lyase activity
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A high-throughput screening assay for hydroxynitrile lyase activity accepting a wide range of HNL-substrates is presented, which is useful either for enzyme fingerprinting or screening of huge variant libraries generated in metagenome or directed evolution approaches. The Royal Society of Chemistry 2006.
- Andexer, Jennifer,Guterl, Jan-Karl,Pohl, Martina,Eggert, Thorsten
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p. 4201 - 4203
(2007/10/03)
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- Design, synthesis, and progress toward optimization of potent small molecule antagonists of CC chemokine receptor 8 (CCR8)
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Activation of CCR8 by its ligand CCL1 may play an important role in diseases such as asthma, multiple sclerosis, and cancer. The study of small molecule CCR8 antagonists will help establish the validation of these hypotheses. We report the design, synthesis, and progress toward optimization of potent small molecule CCR8 antagonists identified from a high-throughput screen. These analogues exhibit good potency in binding and chemotaxis assays, show good selectivity versus the hERG channel, and have good eADME (early absorption, distribution, metabolism, and excretion) profiles.
- Ghosh, Shomir,Elder, Amy,Guo, Jianping,Mani, Ukti,Patane, Michael,Carson, Kenneth,Ye, Qing,Bennett, Robert,Chi, Shannon,Jenkins, Tracy,Guan, Bing,Kolbeck, Roland,Smith, Sean,Zhang, Cheng,LaRosa, Gregory,Jaffee, Bruce,Yang, Hua,Eddy, Priya,Lu, Chuang,Uttamsingh, Vinita,Horlick, Robert,Harriman, Geraldine,Flynn, Daniel
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p. 2669 - 2672
(2007/10/03)
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- Oxidative deoximation with H2O2 and MCM-41
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A simple and mild method of oxidative deoximation with 30%H 2O2 and MCM-41 is described. This method is effective for deprotection of ketones and aldehydes.
- Vijayakumari,Reddy, Balakrishna,Nagarapu, Lingaiah
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p. 407 - 410
(2008/02/10)
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- Catalytic oxidation of alcohols with polymer-supported ruthenium complex under mild conditions
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Polymer-supported ruthenium-containing complex PS-Phen-Ru was synthesized (where PS = chloromethyl polystyrene resin, Phen = 1,10-phenanthroline) and was characterized by FT-IR, ICP, and XPS. The supported complex was used to catalyze the oxidation of primary aliphatic alcohols as well as aromatic alcohols in the presence of iodosylbenzene. The oxidations were carried out in acetonitrile solution, affording the corresponding aldehydes or ketones in high substrate conversion and high selectivities under mild reaction conditions. The catalyst can be easily prepared and can be recycled.
- Kang, Qiao-Xiang,Luo, Ju-Jie,Bai, Yan-Bin,Yang, Zhi-Wang,Lei, Zi-Qiang
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p. 6309 - 6313
(2007/10/03)
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- Design and synthesis of low molecular weight compounds with complement inhibition activity
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An attempt was made to synthesize a series of non-cytotoxic low molecular weight compounds of varying substitutions and functionalities having pharmacophore activity like carbonyl compounds, carboxylic acid and bioisosteres like tetrazole and phenyl acrylic acid. The in vitro assay of these analogues for the inhibition of complement activity revealed significant inhibitory activity for varying substituents and, particularly, for bioisosteres, that is, tetrazole and phenyl acrylic acid derivatives.
- Master, Hoshang E.,Khan, Shabana I.,Poojari, Krishna A.
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p. 4891 - 4899
(2007/10/03)
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- INHIBITORS OF MONOAMINE UPTAKE
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N,N-disubstituted 4-amino-piperidines of the general Formula (I) are inhibitors of the uptake of serotonin and/or norepinephrine and/or dopamine. As such, they may be useful for the treatment of disorders of the central and/or peripheral nervous system.
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Page 138-139
(2010/02/07)
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- A fast and efficient deprotection of aldehydes from acylals using a Wells-Dawson heteropolyacid catalyst (H6P2W 18O62 · 24H2O)
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A rapid and efficient method for the deprotection of aldehyde 1,1-diacetates is described. The reaction was carried out using a Wells-Dawson type catalyst supported on silica. The catalyst, used in 1% molar quantity, is easily recoverable and reusable and maintains the activity after its use in four consecutive reaction batches. The yield of the deprotection was 92-100% (15 examples including nitrobenzaldehyde 1,1-diacetates). Reaction conditions involve short times and the use of toluene as the solvent; isolation is simple and the products are nearly pure.
- Romanelli,Autino,Baronetti,Thomas
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p. 3909 - 3914
(2007/10/03)
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- Oxidation of benzylic alcohols and ethers to carbonyl derivatives by nitric acid in dichloromethane
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Nitric acid in dichloromethane may be successfully employed for the oxidation of benzylic alcohols and ethers to the corresponding carbonyl compounds. The proposed method proved to be of general applicability, affording very good yields of aldehydes and ketones and showing interesting chemoselectivity in many instances, allowing competitive aromatic nitration to be avoided, as well as - in the case of aldehydes - any further oxidation to carboxylic acids. The reaction probably proceeds by a radical mechanism, the active species in the oxidation process being NO2. Competitive formation of nitro esters was observed in some cases, whereas poor results were obtained with allylic and non-benzylic substrates. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Strazzolini, Paolo,Runcio, Antonio
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p. 526 - 536
(2007/10/03)
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- New Applications of 2,4,6-Trichloro-1,3,5-triazine (TT) in Synthesis: Highly Efficient and Chemoselective Deprotection and Ring-Enlargement of Dithioacetals and Oxathioacetals
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Efficient deprotection of a wide variety of 1,3-dithioacetals and 1,3-oxathiolanes to the corresponding carbonyl compounds at room temperature using a combination of 2,4,6-trichloro-1,3,5-triazine (TT) and dimethyl sulfoxide (DMSO) was investigated. In this way, 1,3-oxathioacetals and 1,3-dithioacetals of enolizable ketones were converted to the corresponding 1,4-oxathiepine and 1,4-dithiepine derivatives, respectively.
- Karimi, Babak,Hazarkhani, Hassan
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p. 2547 - 2551
(2007/10/03)
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- Synthesis of low molecular weight compounds with complement inhibition activity
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An attempt was made to synthesize a series of non-cytotoxic low molecular weight meta-substituted aromatic ethers (2-4, 5-7) and some of their bioisosteres (14-16) and to evaluate their activity on the activation of human complement (classical pathway) and their intrinsic hemolytic activity. The in vitro assay results of the inhibition of complement-mediated hemolysis by these analogues indicate that the aldehydic meta substituted aromatic ethers show inhibitory potency, while carboxylic acid meta substituted aromatic ethers show hemolytic activity. Some of the bioisosteres exhibit both inhibitory as well as hemolytic property.
- Master, Hoshang E.,Khan, Shabana I.,Poojari, Krishna A.
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p. 1249 - 1251
(2007/10/03)
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- Quinolinium chlorochromate as an efficient reagent for oxidative cleavage of oximes via the use of microwave irradiation and pestle/mortar
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An effective, eco-friendly and simplistic approach towards the regeneration of aldehydes and ketones from the corresponding oximes has been described, using quinolinium chlorochromate in combination to microwave irradiation and also with a pestle and mortar.
- Singh, Jasvinder,Bhandari, Monica,Kaur, Jasamrit,Kad, Goverdhan L.
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p. 405 - 407
(2007/10/03)
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- Selective oxidation of benzylic alcohols to aldehydes with metal nitrate reagents catalyzed by BEA zeolites or clays
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The oxidation of benzylic alcohols to benzaldehydes by bismuth(III) nitrate was investigated in the presence of various acidic aluminosilicates. The solid acid was used either as support for the nitrate or simply added in the reaction medium as a catalyst of the decomposition of Bi nitrate. The reactivity of the clay-supported reagent is controlled by the dispersion of the nitrate. A high dispersion requires both high surface area and high acidity of the support. There is a good correlation in the oxidation of benzyl alcohol - as the model reaction - between the structure and the chemical activity of the two main groups of supports (K10 and KSF vs. KSF/0 and KP10). In supported reagents made with zeolitic materials such as ZSM-5 or BEA the pores are blocked by the salt, therefore the solvent used for their preparation could not be eliminated completely from the solid. Zeolites cannot, therefore, be used to prepare conventional supported reagents, but work remarkably well, especially BEA, as a catalyst for the oxidation of benzyl alcohol or m-phenoxybenzyl alcohol by bismuth nitrate. Similar oxidation results were obtained with iron(III) nitrate.
- Farkas, Janos,Bekassy, Sandor,Madarasz, Janos,Figueras, Francois
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p. 750 - 754
(2007/10/03)
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- A new phase transfer catalyst and its applications in organic transformations
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A new quaternary ammonium bromide salt has been used for the first time in phase transfer catalysis (PTC) reactions such as oxidation of alcohols to carbonyl compounds, alkylation and esterification reactions. Improved yields and reduced reaction times have been achieved by this procedure.
- Reddy, Ch. Venkateshwar,Mahesh,Raju,Reddy, V.V. Narayana
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p. 2797 - 2802
(2007/10/03)
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- Oxidative deprotection of cyclic acetals and trimethylsilyl ethers by γ-picolinium chlorochromate under nonaqueous conditions
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Deprotection of cyclic acetals and oxidative desilylation of trimethylsilyl ethers into the corresponding carbonyl compounds with γ-picolinium chlorochromate (γ-PCC) under nonaqueous conditions at room temperature is described. Oxidation of aldehydes to carboxylic acids was not observed in any case.
- Salehi,Khodaei,Goodarzi
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p. 1671 - 1673
(2007/10/03)
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- Direct hydrogenation of carboxylic acids to corresponding aldehydes catalyzed by palladium complexes
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A variety of carboxylic acids can be directly hydrogenated into the corresponding aldehydes in high yields by using homogeneous catalysts such as [Pd(PPh3)4] or combination of Pd(OAc)2 with tertiary phosphines in the presence of an excess amount of 2,2-dimethylpropionic anhydride (pivalic anhydride). As a typical example, octanoic acid can be convened into octanal in 99% yield in 3 h at 80 °C under 3.0 MPa of H2 in acetone in the presence of pivalic anhydride and a catalyst system composed of Pd(OAc)2 + 5P(p-tol)3. Such hydrogenation is widely applicable to various aliphatic, aromatic, and heterocyclic carboxylic acids as well as to di- and tribasic carboxylic acids. The process allows the presence of other functional groups such as ketonic carbonyl, nitrile, and ester groups and even internal C=C bonds. Heterogeneous palladium catalyst such as palladium on carbon also showed some catalytic activities.
- Nagayama,Shimizu,Yamamoto
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p. 1803 - 1815
(2007/10/03)
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- γ-picolinium chlorochromate (γ-PCC): A new and efficient reagent for the oxidation of primary and secondary alcohols
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The preparation of γ-picolinium chlorochromate as a new and efficient reagent for the oxidation of primary and secondary alcohols to their corresponding carbonyl compounds in dichloromethane at ambient temperature is described.
- Khodaie,Salehi,Goodarzi
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p. 1253 - 1256
(2007/10/03)
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- The first example of activation of molecular oxygen by nickel in ni-al hydrotalcite: A novel protocol for the selective oxidation of alcohols
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NiO in association with aluminum oxide has been identified by temperature-programmed reduction as the active species in the Ni-Al hydrotalcite catalyst that oxidizes αketols as well as benyzylic and allylic alcohols to their corresponding carbonyl compounds in oxygen in quantitative yields under mild reaction conditions (see scheme).
- Choudary,Kantam, M. Lakshmi,Rahman, Ateeq,Reddy, Ch. Venkat,Rao, K. Koteswara
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p. 763 - 766
(2007/10/03)
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