- Synthesis of novel N- and S-derivatives of 2-naphthol – Promising ligands for the binuclear copper complexes
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N- And S-ligands for binuclear copper complexes were synthesized by the C-sp2-aminomethylation of 2-naphthol with N,N,N′,N′-tetramethyldiaminomethane giving 1-dimethylaminomethyl-2-naphthol, which then reacted with 1,2-ethanedithiol to be converted to thiomethylated derivative. Direct thiomethylation of 2-naphthol and its acetate with formaldehyde and 1,2-ethanedithiol is nonselective, because the reaction involves both O- and C-sp2 reaction centers of the substrate. Binuclear copper complexes with Cu-O-Cu-N or Cu-Cl-Cu-S bonds were prepared.
- Abdullin, Marat F.,Akhmadiev, Nail S.,Akhmetova, Vnira R.,Bikbulatova, El'mira M.,Ibragimov, Askhat G.,Mescheryakova, Ekaterina S.
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- Influence of N-Cetyl-N,N,N-Trimethylammonium Bromide Counterions in the Basic Hydrolysis of Negatively Charged Aromatic Esters
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The addition of counterions, Br-, in the basic hydrolysis of some negatively charged aromatic esters in cationic micelles of N-cetyl-N,N,N-trimethylammonium bromide displaces the substraces from the micellar phase to the aqueous phase.This effect is related to the different interactions of esters with the micelle.
- Vera, S.,Rodenas, E.
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- New microporous lanthanide organic frameworks. synthesis, structure, luminescence, sorption, and catalytic acylation of 2-Naphthol
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New metal-organic frameworks (MOF) with lanthanum(III), cerium(III), neodymium(III), europium(III), gadolinium(III), dysprosium(III), and holmium(III)] and the ligand precursor 1,3,5-tris(4-carboxyphenyl)-2,4,6-trimethylbenzene (H3L) were synthesized unde
- Bahrin, Lucian Gabriel,Bejan, Dana,Janiak, Christoph,K?kcam-Demir, ülkü,Lozan, Vasile,Marangoci, Narcisa Laura,Shova, Sergiu
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- INHIBITON EFFECT OF CATIONIC MICELLES ON THE BASIC HYDROLYSIS OF AROMATIC ESTERS
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The basic hydrolysis of 4-acetoxybenzoic acid and 2-naphtylacetate have been studied in cationic micelles of N-cetyl-N,N,N-trimethylammonium bromide and hydroxide and the results compared with the ones obtained for the basic hydrolysis of acetylsalicylic acid and 3-acetoxy2-naphtoic acid.The results can be explained with the pseudophase kinetic model and the determined second order rate constants in micelles are also smaller than the second order rate constants in water.
- Vera, S.,Rodenas, E.
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Read Online
- Noncross-linked polystyrene nanoencapsulation of ferric chloride: A novel and reusable heterogeneous macromolecular Lewis acid catalyst toward selective acetylation of alcohols, phenols, amines, and thiols
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Ferric chloride has been successfully nanoencapsulated for the first time on a non-cross-linked polystyrene matrix as the shell material via the coacervation technique. The resulting polystyrene nanoencapsulated ferric chloride was used as a novel and rec
- Alinejad, Sara,Donyapeyma, Ghazaleh,Rahmatpour, Ali
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- Magnetically recyclable silica-coated ferrite magnetite-K10montmorillonite nanocatalyst and its applications in O, N, and S-acylation reaction under solvent-free conditions
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Novel silica-coated ferrite nanoparticles supported with montmorillonite (K10) have been prepared successfully by using a simple impregnation method. Further, these nanoparticles were characterized by using different analytical methods like FT-IR, PXRD, EDS, and FE-SEM techniques. In addition, these nanoparticles have been explored for their catalytic activity for the O, N, and S-acylation reactions under solvent-free conditions which gave moderate to excellent yields in a much shorter reaction time. Moreover, these nanoparticles could easily be separated out from the reaction medium after the reaction completion by using an external magnetic field and have been re-used for 10 cycles without any significant loss of the catalytic activity.
- Kumar, Pushpendra,Patil, Shripad M.,Tandon, Nitin,Tandon, Runjhun
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p. 21291 - 21300
(2021/07/01)
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- Steric effect of NHC ligands in Pd(II)–NHC-catalyzed non-directed C–H acetoxylation of simple arenes
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Although there has been a lot of progress in oxidative arene C–H functionalization reactions catalyzed by Pd(II/IV) system, the non-directed, site-selective functionalization of arene molecules is still challenging. It has been established that ligands play a pivotal role in controlling rate- as well as selectivity-determining step in a catalytic cycle involving well-defined metal-ligand bonding. N-heterocyclic carbene (NHC) ligands have had a tremendous contribution in the recent extraordinary success of achieving high reactivity and excellent selectivity in many catalytic processes including cross-coupling and olefin-metathesis reactions. However, the immense potential of these NHC ligands in improving site-selectivity of non-directed catalytic C–H functionalization reactions of simple arenes is yet to be realized, where overriding the electronic bias on deciding selectivity is a burdensome task. The presented work demonstrated an initiative step in this regard. Herein, a series of well-defined discrete [Pd(NHCR′R)(py)I2] complexes with systematically varied degree of spatial congestion at the Pd centre, exerted through the R and R’ substituents on the NHC ligand, were explored in controlling the activity as well as the site-selectivity of non-directed acetoxylation of representative monosubstituted and disubstituted simple arenes (such as toluene, iodobenzene and bromobenzene, naphthalene and 1,2-dichlorobenzene). The resulting best yields were found to be 75% for toluene and 65% for bromobenzene with [Pd(NHCMePh)(py)I2], 75% for iodobenzene and 79% for naphthalene with [Pd(NHCMeMe)(py)I2], and 41% for 1,2-dichlorobenzene with [Pd(NHCCyCy)(py)I2]. Most importantly, with increasing the bulkiness of the NHC ligand in the complexes, the selectivity of the distal C-acetoxylated products in comparison to the proximal ones, was enhanced to a great extent in all cases. Considering the vast library of NHC ligands, this study underscores the future opportunity to develop more strategies to improve the activity and the crucial site-selectivity of C–H functionalization reactions in simple as well as complex organic molecules.
- Mandal, Tanmoy,Yadav, Sudha,Choudhury, Joyanta
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- Method for promoting acylation of amine or alcohol by carbon dioxide
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The invention relates to a method for promoting acylation of amine or alcohol by carbon dioxide, which comprises the following steps of: mixing an amine compound, carboxylate or thiocarboxylate compound and a reaction solvent under the action of carbon dioxide, and reacting to obtain an amide compound, or under the action of carbon dioxide, mixing the alcohol compound, the thiocarboxylate compound and the reaction solvent [gamma]-valerolactone, and reacting to obtain the ester compound. According to the invention, under the promotion action of carbon dioxide, carboxylate or thiocarboxylate is used as an acylation reagent, and amine and alcohol are converted into amide and ester compounds in the absence of a transition metal catalyst, so that acylation reagents such as acyl chloride or anhydride with irritation and corrosivity are avoided; and the method has the advantages of simple operation, mild reaction conditions, high tolerance of substrate functional groups, strong applicability and high yield, and provides an efficient, reliable and economical preparation method for synthesis of amide and ester compounds.
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Paragraph 0034-0035
(2021/05/29)
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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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supporting information
p. 16702 - 16707
(2020/10/27)
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- Nickel-Mediated Trifluoromethylation of Phenol Derivatives by Aryl C?O Bond Activation
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The increasing pharmaceutical importance of trifluoromethylarenes has stimulated the development of more efficient trifluoromethylation reactions. Tremendous efforts have focused on copper- and palladium-mediated/catalyzed trifluoromethylation of aryl halides. In contrast, no general method exists for the conversion of widely available inert electrophiles, such as phenol derivatives, into the corresponding trifluoromethylated arenes. Reported herein is a practical nickel-mediated trifluoromethylation of phenol derivatives with readily available trimethyl(trifluoromethyl)silane (TMSCF3). The strategy relies on PMe3-promoted oxidative addition and transmetalation, and CCl3CN-induced reductive elimination. The broad utility of this transformation has been demonstrated through the direct incorporation of trifluoromethyl into aromatic and heteroaromatic systems, including biorelevant compounds.
- Hu, Wei-Qiang,Pan, Shen,Qing, Feng-Ling,Vicic, David A.,Xu, Xiu-Hua
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supporting information
p. 16076 - 16082
(2020/07/04)
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- Environmentally benign decarboxylative: N-, O-, and S-Acetylations and acylations
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An operationally simple and general method for acetylation and acylation of a wide variety of substrates (amines, alcohols, phenols, thiols, and hydrazones) has been reported. Meldrum's acid and its derivatives have been used as an air-stable, non-volatile, cost-effective, and easy to handle acetylating/acylating agent. Easily separable byproducts (CO2 and acetone) allowed the isolation of analytically pure acetylated products without the requirement of work-up and any chromatography. This journal is
- Ghosh, Santanu,Purkait, Anisha,Jana, Chandan K.
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supporting information
p. 8721 - 8727
(2020/12/30)
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- 4-Imidazol-1-yl-butane-1-sulfonic acid ionic liquid: Synthesis, structural analysis, physical properties and catalytic application as dual solvent-catalyst
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4-Imidazol-1-yl-butane-1-sulfonic acid (ImBu-SO3H) has been successfully synthetized and fully characterized by FT-IR and high-resolution NMR spectroscopy (1H, 13C). The “plausible” alternative structures of ImBu-SO3H were discussed on the basis of its NMR data. The ionic liquid showed interesting dual solvent-catalyst property, which was studied experimentally for the acetylation of a variety of functionalized alcohols, phenols, thiols, amines and α-tocopherol (α-CTP) as the most active form of vitamin E with acetic anhydride and which provided good yields within a short reaction time. ImBu-SO3H was successfully recycled by product extraction with an average recovered yield of 82% for 5 subsequent runs. The catalytic activity of the recycled ImBu-SO3H showed almost no loss even after five consecutive runs.
- Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie,Juan, Joon Ching
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p. 866 - 878
(2019/07/12)
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- Manganese-mediated acetylation of alcohols, phenols, thiols, and amines utilizing acetic anhydride
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Manganese(II) chloride-catalyzed acetylation of alcohols, phenols thiols and amines with acetic anhydride is reported. This method is environment-friendly and economically viable as it involves inexpensive, relatively benign catalyst, mild reaction condition, and simple workup. Acetylation is performed under the solvent-free condition at ambient temperature and acetylated products obtained in good to excellent yields. Primary, secondary heterocyclic amines, and phenols with various functional groups are smoothly acetylated in good yields. This method exhibits exquisite chemoselectivity, the amino group is preferentially acetylated in the presence of a hydroxyl/thiol group.
- Jain, Isha,Sharma, Ramandeep,Malik, Payal
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supporting information
p. 2952 - 2960
(2019/09/13)
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- Iodine(III)-Mediated, Controlled Di- or Monoiodination of Phenols
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An oxidative procedure for the electrophilic iodination of phenols was developed by using iodosylbenzene as a nontoxic iodine(III)-based oxidant and ammonium iodide as a cheap iodine atom source. A totally controlled monoiodination was achieved by buffering the reaction medium with K3PO4. This protocol proceeds with short reaction times, at mild temperatures, in an open flask, and generally with high yields. Gram-scale reactions, as well as the scope of this protocol, were explored with electron-rich and electron-poor phenols as well as heterocycles. Quantum chemistry calculations revealed PhII(OH)·NH3 to be the most plausible iodinating active species as a reactive "I+" synthon. In light of the relevance of the iodoarene moiety, we present herein a practical, efficient, and simple procedure with a broad functional group scope that allows access to the iodoarene core unit.
- Satkar, Yuvraj,Yera-Ledesma, Luisa F.,Mali, Narendra,Patil, Dipak,Segura-Quezada, Luis A.,Ramírez-Morales, Perla I.,Solorio-Alvarado, César R.,Navarro-Santos, Pedro
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p. 4149 - 4164
(2019/04/30)
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- Copper-Catalyzed Acetylation of Electron-Rich Phenols and Anilines
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An approach has been developed for the copper-catalyzed acetylation of phenols and anilines with potassium thioacetate as an acetylating reagent. Although only electron-rich phenols and anilines are compatible with this protocol, the reaction can provide moderate to high yields under mild conditions. Compared with other acetylating reagents, the current reagent has certain advantages, such as its low cost, easy availability, stability, insensitivity to water or air, and ease of storage.
- Zhang, Jieyu,Ke, Qiumin,Tian, Feitao,Jiang, Bei,Ji, Chang-An,Zhang, Lingling,Yu, Jian,Huang, Dayun,Yan, Guobing
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supporting information
p. 726 - 730
(2019/03/26)
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- Method for synthesizing phenyl acetate derivatives
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The invention discloses a method for synthesizing phenyl acetate derivatives. The method of the invention comprises the following steps: 1, adding a phenol derivative, potassium thioacetate, copper acetate and acetonitrile to a reaction tube, and tightening the bottle stopper of the reaction tube, and magnetically stirring at 80 DEG C and reacting for 4 h; and 2, extracting with ethyl acetate, mixing organic phases, removing most of the solvent by reduced pressure distillation, and carrying out column chromatography separation and purification on residual mixed liquor by using petroleum etherand ethyl acetate at the volume ratio of 10:1 as a leacheate so as to obtain a target product. By using a phenol derivative as the raw material and using stable potassium thioacetate, which is cheap and easily available and is easy to operate, as an acetylation reagent, a series of phenyl acetate derivatives are efficiently synthesized, and the yield is considerable.
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Paragraph 0015-0020
(2019/05/08)
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- Acceptorless Dehydrogenation of Hydrocarbons by Noble-Metal-Free Hybrid Catalyst System
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A hybrid catalysis that comprises an acridinium photoredox catalyst, a thiophosphate organocatalyst, and a nickel catalyst-enabled acceptorless dehydrogenation of hydrocarbons is reported. The cationic nickel complex played a critical role in the reactivity. This is the first example of acceptorless dehydrogenation of hydrocarbons by base metal catalysis under mild reaction conditions of visible light irradiation at room temperature.
- Fuse, Hiromu,Kojima, Masahiro,Mitsunuma, Harunobu,Kanai, Motomu
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p. 2042 - 2045
(2018/04/16)
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- Preparation method of aryl carboxylate compound based on alkenyl carboxylate ester exchange reaction
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The invention provides a preparation method of an aryl carboxylate compound based on alkenyl carboxylate ester exchange reaction and belongs to the technical field of pharmaceutical chemical intermediates and related chemistry. According to the method, phenol and alkenyl carboxylate are used as raw materials and green and efficient synthesis of the aryl carboxylate compound is realized under the catalysis effect of alkali. The method has the advantages of high selectivity, moderate reaction conditions, good functional group compatibility, wide substrate range, environment friendliness and thelike. The aryl carboxylate compound is an important organic synthetic intermediate and has very wide application in the fields of organic synthesis and pharmacology, so that the preparation method hasvery great application value and social economic benefits.
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Paragraph 0043; 0044; 0045
(2018/10/11)
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- Na 2 CO 3-Catalyzed O-Acylation of Phenols for the Synthesis of Aryl Carboxylates with Use of Alkenyl Carboxylates
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Inorganic base-catalyzed O-acylation of phenol and its derivatives has been developed. The procedure provides an efficient catalysis system for the preparation of aryl carboxylates with alkenyl carboxylates as acyl reagents. The reaction proceeded smoothly by using ?-Na 2 CO 3 as the catalyst in MeCN to produce the corresponding aryl carboxylates in good to excellent yields.
- Zhou, Xiao-Yu,Chen, Xia
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supporting information
p. 2321 - 2325
(2018/10/20)
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- Phenol Derivatives in Ruthenium-Catalyzed C–H Arylation: A General Synthetic Access to Azole-Based Congested Polyaromatics
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Aryl triflates and related phenolates are suitable electrophile coupling partners for the ruthenium-catalyzed direct arylation of heteroaromatic substrates using azole N-directed Csp2–H activation. We report herein convenient conditions for the efficient ortho-C–H functionalization of aryl-pyrazoles, thiazoles and pyridines in which [RuCl2(p-Cym)]2 precatalyst is employed with pivalic acid (PivOH) as co-catalyst. Different phenolate derivatives were successfully coupled, which tolerate a large scope of electron-rich substituents in para-, meta- and highly hindered ortho-position. Electron-withdrawing aryl triflates were found to be less reactive, making the general reactivity of these electrophiles complementary to those of aryl chlorides and deactivated bromides. This cost-effective ruthenium C–H activation/arylation synthesis of poly(hetero)aromatics was concurrently examined using triflates, mesylates, sulfonates, and carbonates, and was also successfully extended to the use of diethyl carbonate as an eco-friendly solvent.
- Roger, Julien,Hierso, Jean-Cyrille
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supporting information
p. 4953 - 4958
(2018/09/25)
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- Protection of COOH and OH groups in acid, base and salt free reactions
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We report an iron-catalyzed general functional group protection method with inexpensive reagents. This environmentally benign process does not use acids or bases, and does not produce waste products. Further purification beyond filtration and evaporation is, in most cases, unnecessary. Free COOH and OH groups can be protected in a one-pot reaction.
- Zhu, Xiaotao,Qian, Bo,Wei, Rongbiao,Huang, Jian-Dong,Bao, Hongli
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supporting information
p. 1444 - 1447
(2018/04/12)
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- Preparation method for synthesis of phenolic ester through thiocarboxylic acid mediated visible light catalyzed phenol acylation reaction
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The invention discloses a preparation method for synthesis of phenolic ester through a thiocarboxylic acid mediated visible light catalyzed phenol acylation reaction. Thiocarboxylic acid compounds andphenol compounds are subjected to a site specific reaction under certain conditions to produce phenolic ester compounds, wherein the certain conditions are as follows: under the conditions of normaltemperature, normal pressure and visible light, K2CO3 is used as an alkaline catalyst, terpyridyl ruthenium dichloride hexahydrate is used as a photosensitizer and acetonitrile is used as a reaction solvent. Synthesis of phenolic ester under catalysis of visible light is realized, thiocarboxylic acid is used as an acylation reagent, and the site specific phenol esterification reaction is realizedefficiently under mild conditions of normal temperature, normal pressure and visible light. The method has mild reaction conditions, large substrate functional group tolerance, high applicability andhigh yield, and an efficient, reliable and economical preparation method is provided for synthesis of phenolic ester.
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Paragraph 0079; 0080; 0091; 0092; 0093
(2018/07/30)
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- Reusable and efficient polyvinylpolypyrrolidone-supported triflic acid catalyst for acylation of alcohols, phenols, amines, and thiols under solvent-free conditions
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Abstract: A triflic acid-functionalized polyvinylpolypyrrolidone was prepared and fully characterized by FT-IR, TGA, and SEM. This super acidic solid catalyst shows high catalytic activity for selective acylation of alcohols, phenols, amines, and thiols with anhydrides under solvent-free conditions at room temperature. In addition, this method features an easy to handle solid super acid catalyst and an operationally simple procedure, affording the desired acylated products in excellent yields. Graphical abstract: [Figure not available: see fulltext.].
- Tajbakhsh, Mahgol,Tajbakhsh, Mahmoud,Khaksar, Samad,Gazvini, Helia Janatian,Heidary, Marzieh
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p. 1117 - 1122
(2017/05/10)
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- Polymer-Supported Palladium(II) Carbene Complexes: Catalytic Activity, Recyclability, and Selectivity in C?H Acetoxylation of Arenes
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Heterogeneous catalysts for selective oxidation of C?H bonds were synthesized by co-polymerization of new N-heterocyclic carbene-palladium(II) (NHC-PdII) monomers with divinylbenzene. The polymer-supported NHC-PdII-catalysed undirect
- Majeed, Maitham H.,Shayesteh, Payam,Wallenberg, L. Reine,Persson, Axel R.,Johansson, Niclas,Ye, Lei,Schnadt, Joachim,Wendt, Ola F.
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supporting information
p. 8457 - 8465
(2017/06/28)
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- Asymmetric Alkynylation of β-Ketoesters and Naphthols Promoted by New Chiral Biphenylic Iodanes
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The preparation of new chiral biphenylic λ3-iodane reagents bearing transferable alkynyl ligands is described. These reagents transfer their carbon-based ligands onto β-ketoesters with an enantiomeric excess (ee) up to 68 %, and most remarkably, enable the dearomative alkynylation of naphthols in good to high yields up to 84 % ee.
- Companys, Simon,Peixoto, Philippe A.,Bosset, Cyril,Chassaing, Stefan,Miqueu, Karinne,Sotiropoulos, Jean-Marc,Pouységu, Laurent,Quideau, Stéphane
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supporting information
p. 13309 - 13313
(2017/10/05)
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- Synthesis, structure and multifunctional catalytic properties of a Cu(i)-coordination polymer with outer-hanging CuBr2
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A 1D Cu(i)-coordination polymer [(CuL1)(CuBr2), 1] carrying external copper bromide moieties was synthesized. The outer-hanging [CuBr2]- moiety is attached to the 1D Cu(i)-CP backbone via a Cu?Cu bonding interaction, which makes it look like a coordination polymer supported CuBr2 species. 1 exhibits excellent multifunctional catalytic activity for phenol acetylation, A3-coupling (aldehyde-alkyne-amine) and styrene oxide methanolysis reactions. Its heterogeneous catalytic nature was confirmed by solution leaching experiment and it can be reused without significant loss of its catalytic activity and selectivity for the above reactions.
- Zhu, Neng-Xiu,Zhao, Chao-Wei,Yang, Jing,Wang, Xue-Ru,Ma, Jian-Ping,Dong, Yu-Bin
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p. 108645 - 108653
(2016/11/30)
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- TiCl4/Et3N-Mediated Condensation of Acetate and Formate Esters: Direct Access to β-Alkoxy- and β-Aryloxyacrylates
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A methodology to build (E)-β-alkoxy- and (E)-β-aryloxyacrylate moieties from acetate and formate esters promoted by the TiCl4/Et3N system is presented. The reaction is compatible with a broad range of structural skeletons and elapses through an unusual condensation pathway. Taking into account the obtained results, we propose a plausible mechanism involving a bimetallic titanium intermediate for this type of transformation.
- álvarez-Calero, José María,Jorge, Zacarías D.,Massanet, Guillermo M.
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supporting information
p. 6344 - 6347
(2016/12/23)
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- Highly efficient and recyclable acetylation of phenols and alcohols by nickel zirconium phosphate under solvent-free conditions
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Nickel zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetylation of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma optical emission spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity.
- Hajipour, Abdol Reza,Karimi, Hirbod,Kohi, Afshin
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- Preparation, characterization and application of RHA/TiO2 nanocomposites in the acetylation of alcohols, phenols and amines
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In this work, anatase-phase nano-titania was prepared by embedding in rice husk ash, and identified using a variety of techniques. The obtained nanocomposite (RHA/TiO2) was used as a green and inexpensive catalyst for the promotion of the acetylation of alcohols, phenols and amines with Ac2O at room temperature under solvent free conditions. The procedure gave the products in excellent yields during all reaction times. Also this catalyst can be reused for several times without loss of its catalytic activity.
- Seddighi, Mohadeseh,Shirini, Farhad,Goli-Jolodar, Omid
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p. 1003 - 1010
(2016/08/08)
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- Efficient and selective N-, S- and O-acetylation in TEAA ionic liquid as green solvent. Applications in synthetic carbohydrate chemistry
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Background: The ionic liquid triethylammonium acetate (TEAA) was found to be an efficient solvent in the acetylation of alcohols, amines, oximes and thiols to their corresponding acetyl compounds using only a 10% excess of acetic anhydride under mild conditions. Moreover TEAA is not only an inexpensive and recyclable solvent but also an anomeric selective catalyst in the per-O-acetylation of sugar moieties. Methods: Simple and effective organic synthesis protocols were provided for the selective acetylation of several substrates. The products were fully characterized by 1H and 13C NMR spectroscopy and the anomeric ratios were obtained from the 1H spectra. Results: Structurally diverse alcohols, phenols, thiols, amines, carbohydrates and oximes underwent acylation under mild conditions by this procedure to provide the corresponding acetates in excellent yields. TEAA ionic liquid is unique in its capability to act as both, solvent and high selective catalyst. As expected, the reaction proceeds with high b anomeric selectivity for sugars derivatives. Moreover, the ionic liquid was regenerated, recycled and reused for three times without apparent loss of reactivity and selectivity in all cases. Conclusions: The present procedure provides a powerful and versatile acylation method for alcohols, phenols, thiols, amines, oximes and carbohydrates. This protocol is endowed with several unique merits: selectivity, cost-efficiency, atom-economy and mild reaction conditions tolerable to acid sensitive functionalities. With these features, this method may be considered as a better alternative for the acetylation of a wide range of substrates.
- Lafuente, Leticia,Díaz, Gisela,Bravo, Rodolfo,Ponzinibbio, Agustín
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p. 195 - 200
(2016/02/26)
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- Doping of copper (I) oxide onto a solid support as a recyclable catalyst for acetylation of amines/alcohols/phenols and synthesis of trisubstituted imidazole
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A study of copper-mediated C-heteroatom especially C-N and C-O bond formations using simpler methodologies has been carried out. In the present work, acetylation of various substrates such as amines, phenols and alcohols; synthesis of 2,4,5-trisubstituted imidazole is done using simple and easily available starting materials. Copper (I) oxide was synthesized in situ by the reduction of Fehling's solution with glucose followed by its anchoring onto different supports like silica, HAP, basic alumina and cellulose. Comparison and contrasts between the reactivity of copper (I) oxide supported onto different supports for these reactions are made. The reactivity of copper (I) oxide seems to be largely dependent on the nature of support and the most active catalyst for a particular reaction was further characterized by different spectroscopic techniques such as FTIR, XRD, TGA, XPS, SEM, TEM and AAS. The catalysts were found to be stable, easily recyclable without any significant loss in activity. Graphical abstract: Applications of solid supported copper (I) oxides (where solid support is silica, HAP, cellulose and basic alumina) are studied for various organic transformations with special emphasis on C-N and C-O bond formation reactions.[Figure not available: see fulltext.]
- Gupta, Manjulla,Gupta, Monika
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p. 231 - 241
(2016/01/09)
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- Palladium-Catalyzed Carbonylative Synthesis of Aryl Formates under Mild Conditions
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Aryl formates have been extensively applied as CO sources in CO-free carbonylation reactions. However, there are no catalytic synthetic procedures for their preparation. In this manuscript, we developed a convenient palladium-catalyzed procedure for the synthesis of aryl formates. Good yields were achieved under mild reaction conditions with formic acid as the formyl source. A formyl meeting: A convenient palladium-catalyzed carbonylation procedure for the synthesis of aryl formates is developed. Good yields are achieved under mild reaction conditions with formic acid as the formyl source.
- Jiang, Li-Bing,Li, Rui,Li, Hao-Peng,Qi, Xinxin,Wu, Xiao-Feng
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p. 1788 - 1791
(2016/06/01)
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- Ligand-Promoted Palladium-Catalyzed C?H Acetoxylation of Simple Arenes
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The palladium-catalyzed C?H oxidation of simple arenes is an attractive strategy to obtain phenols, which have many applications in the fine chemicals industry. Although some advances have been made in this research area, low reactivity and selectivity are, in general, observed. This report describes a new catalytic system for the efficient C?H acetoxylation of simple arenes based on Pd(OAc)2 and a pyridinecarboxylic acid ligand.
- Valderas, Carolina,Naksomboon, Kananat,Fernández-Ibá?ez, M. ángeles
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p. 3213 - 3217
(2016/10/24)
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- Porous coordination polymers of diverse topologies based on a twisted tetrapyridylbiaryl: Application as nucleophilic catalysts for acetylation of phenols
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Porous coordination polymers (CPs) with partially uncoordinated pyridyl rings based on rationally designed polypyridyl linkers are appealing from the point of view of their application as nucleophilic catalysts. A D2d--symmetric tetradentate organic linker L, that is, 2,2 ',6,6'-tetramethoxy-3,3',5,5'-tetrakis(4-pyridyl)biphenyl, was designed and synthesized for metal-assisted self-assembly aimed at porous CPs. Depending on the nature of the metal ion and the counter anion, the ligand L is found to function as a 3- or 4-connecting building block leading to porous CPs of diverse topologies. The reaction of L with Zn(NO3)2 and Cd(NO3)2 yields porous 2D CPs of "fes" topology, in which the tetrapyridyl linker L serves as a 3-connecting unit with its free pyridyl rings well exposed into the pores. The functional utility of these porous CPs containing uncoordinated pyridyl rings is demonstrated by employing them as efficient heterogeneous nucleophilic catalysts for acetylation of a number of phenols with varying electronic properties and reactivities.
- Seth, Saona,Venugopalan, Paloth,Moorthy, Jarugu Narasimha
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p. 2241 - 2249
(2015/01/30)
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- Acetylation of alcohols and phenols under solvent-free conditions using iron zirconium phosphate
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Iron zirconium phosphate (ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields under solvent-free conditions. The steric and electronic properties of various substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma-optical emission spectrometry, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 9.3 ? when Fe3+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several important advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.
- Hajipour, Abdol R.,Karimi, Hirbod,Masti, Amir
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p. 595 - 602
(2015/09/28)
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- Simple and Efficient Process for the Large-Scale Preparation of Agomelatine: An Antidepressant Drug
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A simple and efficient process for the large-scale preparation of agomelatine (1), an antidepressant drug is, described. Agomelatine was prepared in a linear manner starting from readily available, inexpensive 2-naphthol. Key steps in the synthesis are Friedel-Crafts acylation of 2-naphthyl acetate with chloroacetyl chloride, reduction of keto intermediate, and nucleophilic displacement of chloro intermediate with sodium diformylamide. A systemic approach was described to streamline the process into a robust scalable process by controlling the impurities.
- Vujjini, Satish Kumar,Vyala, Sunitha,Badarla, Krishna Rao,Kandala, Sreenatha Charyulu,Bandichhor, Rakeshwar,Kagga, Mukkanti,Cherukupalli, Praveen
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supporting information
p. 1864 - 1870
(2015/08/03)
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- Tribromoisocyanuric acid (TBCA) as a mild and metal free catalyst for the acetylation and formylation of hydroxyl groups under solvent free conditions
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A convenient approach for acetylation and formylation of various types of alcohols and phenols with acetic anhydride and formic acid in the presence of Tribromoisocyanuric acid (TBCA) as catalyst is reported. The reactions were carried out under solvent-free condition and in good to high yields at room temperature. This present method is featured with relatively mild reaction conditions, simple operation, broad substrate scope, clean work-up, short reaction times, good to high yields, excellent selectivity and also avoids tedious purifications and the use of toxic reagents.
- Hekmatian, Zahra,Khazaei, Ardeshir
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p. 1565 - 1570
(2016/01/26)
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- The first vinyl acetate mediated organocatalytic transesterification of phenols: A step towards sustainability
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The present report outlines our efforts toward a simple yet elegant protocol for O-acylation of a wide variety of phenols. This highly enabling and solventless method relies on vinyl acetate as an innocuous acyl donor and DABCO as an organocatalyst. Operational simplicity, excellent yields, higher and faster conversion rates without excess reagents, a simple workup and essentially no need of columns are some of the salient features of the reported protocol.
- Kumar, Manoj,Bagchi, Sourav,Sharma, Anuj
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supporting information
p. 8329 - 8336
(2015/11/10)
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- Rhodium-catalyzed borylation of aryl and alkenyl pivalates through the cleavage of carbonoxygen bonds
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Rhodium-catalyzed borylation reactions of aryl and alkenyl pivalates, using a diboron reagent, via the cleavage of carbonoxygen bonds have been developed. The inert nature of the pivalate moiety enables relatively complex aryl boronates to be synthesized via the tandem cross-coupling of carbonhalogen and carbonoxygen bonds.
- Kinuta, Hirotaka,Hasegawa, Junya,Tobisu, Mamoru,Chatani, Naoto
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supporting information
p. 366 - 368
(2015/03/30)
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- The Baeyer-Villiger oxidation versus aromatic ring hydroxylation: Competing organic peracid oxidation mechanisms explored by multivariate modelling of designed multi-response experiments
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Peroxy acids can be used as the terminal oxidant for the Baeyer-Villiger oxidation of acetophenones and for direct ring hydroxylation of methoxy-substituted benzenes. An oxidative system involving 3-chloroperbenzoic acid (mCPBA) and 2,6-dimethoxyacetophenone as model substrate was investigated by means of statistical experimental design, multivariate modelling and response surface methodology. The outcome of the organic peracid oxidation experiments was portrayed by a multi-response matrix consisting of the yields of three different compounds; 2,6-dimethoxyphenyl acetate, 1-(4-hydroxy-2,6-dimethoxy-phenyl)ethanone and 3-hydroxy-2,6-dimethoxy-phenyl acetate. The optimized reaction protocol was utilized to investigate a series of various substituted acetophenones. The overall investigation revealed that both the molecular structure of the acetophenone substrate and the experimental conditions exhibited a substantial impact on whether the oxidation reaction follows the oxygen insertion or direct ring hydroxylation mechanism. An improved protocol for the direct ring hydroxylation was also obtained from the experimental and modelling described herein.
- Gambarotti, Cristian,Bj?rsvik, Hans-René
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p. 619 - 628
(2015/09/28)
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- Palladium-Catalyzed Desilylative Acyloxylation of Silicon-Carbon Bonds on (Trimethylsilyl)arenes: Synthesis of Phenol Derivatives from Trimethylsilylarenes
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A strategy for desilylative acetoxylation of (trimethylsilyl)arenes has been developed in which (trimethylsilyl)arenes are converted into acetoxyarenes. The direct acetoxylation is performed in the presence of 5 mol % of Pd(OAc)2 and PhI(OCOCF3)2 (1.5 equiv) in AcOH at 80°C for 17 h. The acetoxyarenes are obtained in good to high yields (67-98%). The synthetic utility is demonstrated with a one-pot transformation of (trimethylsilyl)arenes to phenols by successive acetoxylation and hydrolysis. Furthermore, desilylative acyloxylation of 2-(trimethylsilyl)naphthalene using several carboxylic acids has been conducted.
- Gondo, Keisuke,Oyamada, Juzo,Kitamura, Tsugio
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supporting information
p. 4778 - 4781
(2015/10/12)
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- Iron-Catalyzed Cross-Coupling of Alkenyl Acetates
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Stable C-O linkages are generally unreactive in cross-coupling reactions which mostly employ more electrophilic halides or activated esters (triflates, tosylates). Acetates are cheap and easily accessible electrophiles but have not been used in cross-couplings because the strong C-O bond and high propensity to engage in unwanted acetylation and deprotonation. Reported herein is a selective iron-catalyzed cross-coupling of diverse alkenyl acetates, and it operates under mild reaction conditions (0 C, 2 h) with a ligand-free catalyst (1-2 mol%). Iron clad: Acetates are underutilized electrophiles in metal-catalyzed cross-coupling reactions because of the strong alkenyl C-O bond and their propensity to engage in unwanted reactions. Combination of a ligand-free low-valent Fe catalyst with nucleophilic organomagnesium reagents, low temperature, and short reaction times results in highly selective cross-couplings with alkenyl acetates.
- G?rtner, Dominik,Stein, André Luiz,Grupe, Sabine,Arp, Johannes,Von Wangelin, Axel Jacobi
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supporting information
p. 10545 - 10549
(2015/09/02)
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- Tris(pentafluorophenyl)borane catalyzed acylation of alcohols, phenols, amines, and thiophenols under solvent-free condition
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The acylation of alcohols, phenols, amines, and thiophenols was accomplished with 0.5 mol % of tris(pentafluorophenyl)borane [B(C 6F5)3] at ambient temperature under solvent-free condition. Major advantages of this method include high yield, short reaction time, simple procedure, compatibility with sensitive protecting groups as well as other functional groups, absence of racemization of optical active compounds, and epimerization of sugars.
- Prajapti, Santosh Kumar,Nagarsenkar, Atulya,Babu, Bathini Nagendra
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p. 1784 - 1787
(2014/03/21)
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- Rice husk ash: A new, cheap, efficient, and reusable reagent for the protection of alcohols, phenols, amines, and thiols
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Amild, efficient, and eco-friendly protocol for the protection of alcohols and phenols as trimethylsilyl ethers has been developed using rice husk ash as a reagent. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols, and amines with acetic anhydride. All reactions were performed under mild conditions in good to high yields. Copyright
- Shirini,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali
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p. 577 - 586
(2014/06/09)
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- Solventless acetylation of alcohols and phenols catalyzed by supported iron oxide nanoparticles
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Supported iron oxide nanoparticles on silicate catalysts were found to be efficient and easily recoverable materials in the acetylation of alcohols and phenols to their corresponding acetyl compounds using acetic anhydride under mild and solvent-less conditions. The supported iron oxide nanoparticles could be easily recovered from the reaction mixture and reused ten times without any loss in activity.
- Rajabi, Fatemeh,Luque, Rafael
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p. 129 - 132
(2014/01/06)
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- Vitamin B1 supported on silica-encapsulated γ-Fe 2O3 nanoparticles: Design, characterization and application as a greener biocatalyst for highly efficient acylation
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A new magnetic catalyst was synthesized by the immobilization of vitamin B1 (thiamine hydrochloride) on the surface of silica-encapsulated γ-Fe2O3 nanoparticles. Its capability was evaluated in the acylation of alcohols and phenols with acetic anhydride under solvent-free conditions and afforded the desired products in high yield. This novel magnetic organocatalyst could be separated from the reaction vessel by use of an external magnet and recovered 5 times without a significant loss of its activity. The amount of loaded vitamin B1 on the silica-encapsulated γ-Fe2O3 was assigned by TGA and confirmed by back titration. Availability, cheapness and low toxicity are reasons associated with the utilization of vitamin B1 as a catalyst. The catalyst has been characterized by FT-IR, XRD, SEM, VSM and TG/DTA. The Royal Society of Chemistry.
- Azizi, Kobra,Heydari, Akbar
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p. 8812 - 8816
(2014/03/21)
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- Silica-supported boric acid catalyzed synthesis of dihydropyrimidin-2-ones, bis(indolyl)methanes, esters and amides
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Silica-supported boric acid (H3BO3-SiO2) has been established as a green, efficient and recyclable catalyst for the synthesis of dihydropyrimidin-2-ones, bis(indolyl)methanes, and acetylation of alcohols, phenols, amines and thiols under solvent free conditions. The main features of the present method include clean reaction, mild conditions, low loading of environment friendly catalyst and easy workup procedure. The catalyst can be recycled at least five times without any significant loss in activity.
- Kumar, Vishal,Singh, Chitra,Sharma, Upendra,Verma, Praveen K.,Singh, Bikram,Kumar, Neeraj
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- Synthesis, characterization and application of poly(N,N'-dibromo- Nethylnaphthyl-2,7-disulfonamide) as an efficient catalyst for the acetylation and deacetylation reactions
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In this work, a novel polymer namely poly(N,N'-dibromo-N-ethylnaphthyl-2,7- disulfonamide) (PBNS) is synthesized and characterized by studying its IR, 1H NMR, 13C NMR and thermal gravimetric analysis (TGA). This polymer is utilized as a highly efficient, heterogeneous and recyclable N-bromo reagent to catalyze acetylation of various compounds such as alcohols, phenols, thiol and amine with acetic anhydride under solvent-free conditions, and also it worthily catalyzes deacetylation of acetate esters in aqueous media.
- Khazaei, Ardeshir,Saednia, Shahnaz,Roshani, Liela,Kazem-Rostami, Masoud,Zare, Abdolkarim
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p. 159 - 167
(2014/05/20)
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- Total synthesis of agomelatine via Friedel-Crafts acylation followed by Willgerodt-Kindler reaction
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Total synthesis of antidepressant drug, agomelatine is reported. Regio selective Friedel-Crafts acylation followed by Willgerodt-Kindler reactions is used as the key steps for the synthesis of agomelatine.
- Vujjini, Satish Kumar,Datla, V.R. Krishnam Raju,Badarla, Krishna Rao,Vetukuri, V.N.K.V. Prasada Raju,Bandichhor, Rakeshwar,Kagga, Mukkanti,Cherukupally, Praveen
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supporting information
p. 3885 - 3887
(2014/07/08)
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- Microwave-assisted acetylation of phenols without catalyst under solvent free condition
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Etherification between phenols with acetic anhydride was tested under different conditions. Phenols were efficiently acylated with acetic anhydride to give phenol acetate derivatives in good high yields without catalyst and solventless conditions under microwave irradiation.
- Zhang, Yu-Quan,Li, Yan-Chun,Zhu, Ji-Hua,Li, Zhi-Feng,Guo, Guo-Zhe,Chen, Dong-Ping
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p. 7746 - 7748
(2015/02/02)
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- Acetylation of alcohols and phenols under solvent-free conditions using copper zirconium phosphate
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Copper zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetylation of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively-coupled plasma optical emission spectroscopy, energy dispersive spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 8.0 ? when Cu2+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several key advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.
- Hajipour, Abdol R.,Karimi, Hirbod
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p. 1982 - 1989
(2015/09/28)
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- Preparation and characterization of multi-walled carbon nanotubes (MWCNTs), functionalized with phosphonic acid (MWCNTs-C-PO3H2) and its application as a novel, efficient, heterogeneous, highly selective and reusable catalyst for acetylation of alcohols, phenols, aromatic amines, and thiols
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A novel, efficient, heterogeneous, and reusable multi-walled carbon nanotubes (MWCNTs), functionalized with phosphonic acid (MWCNTs-C-PO 3H2) has been synthesized. The synthesized CNTs were characterized using some electron microscopic techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), Energy dispersive X-ray spectroscopy (EDAX), and also some thermal and spectroscopic methods such as thermogravimetry (TG). The nitrogen adsorption behavior of the MWCNTs-C-PO3H2 catalyst was evaluated using the TG instrumentation system at 25°C. The catalyst was applied successfully for highly efficient and selective acetylation of alcohols, phenols, thiols and aromatic amines with acetic anhydride at room temperature under solvent-free conditions. The reusability of the catalyst was checked and the recovered catalyst was reused for five runs without significant loss in activity.
- Dehghani, Farzaneh,Sardarian, Ali Reza,Doroodmand, Mohammad Mehdi
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p. 673 - 684
(2014/05/20)
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