cas 829-20-9, 2,4-Dimethoxyacetophenone | Articles data

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Peptoid Helix Displaying Flavone and Porphyrin: Synthesis and Intramolecular Energy Transfer
Natural light-harvesting complexes (LHCs) absorb a broad spectrum of sunlight using a collection of photosynthetic pigments whose spatial arrangement is controlled by a protein matrix and exhibit efficient energy transfer. We constructed a novel light-harvesting protein mimic, which absorbs light in the UV to visible region (280-700 nm) by displaying flavone and porphyrin on a peptoid helix. First, an efficient synthesis of 4′-derivatized 7-methoxyflavone (7-MF, 3 and 4) was developed. The flavone-porphyrin-peptoid conjugate (FPPC) was then prepared via Miyaura borylation on a resin-bound peptoid followed by Suzuki coupling between the peptoid and pigment. Circular dichroism spectroscopy indicated that the FPPC underwent helix-to-loop conversion of the peptoid scaffold upon changing the solvent conditions. A distinct intramolecular energy transfer was observed from 7-MF to porphyrin with greater efficiency in the helix than that in the loop conformation of the peptoid, whereas no clear evidence of energy transfer was obtained for unstructured FPPC. We thus demonstrate the value of the helical peptoid, which provided a controlled orientation for 7-MF and porphyrin and modulated the energy transfer efficiency via conformational switching. Our work provides a way to construct a sophisticated LHC mimic with enhanced coverage of the solar spectrum and controllable energy transfer efficiency.
Yang, Woojin,Jo, Junhyuk,Oh, Hyeongyeol,Lee, Hohjai,Chung, Won-Jin,Seo, Jiwon
p. 1392 - 1400
(2020)
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Dihydropyrazole MurA enzyme inhibitor molecule as well as preparation method and application thereof
The invention provides a dihydropyrazole MurA enzyme inhibitor molecule as well as a preparation method and application thereof. The structural formula is shown in the specification, R is a direct-connected alkyl group with the chemical formula of CnH2n+1, and n is equal to 1-7. The preparation method comprises the following steps of by taking acetophenone substances with different substituent groups and 4-(4-methyl piperazinyl) benzaldehyde as raw materials, carrying out aldol condensation reaction under an alkaline condition to obtain an intermediate, and synthesizing a target compound with a structural formula by using the intermediate, hydrazine hydrate and an organic acid with an R-COOH structure. The dihydropyrazole MurA enzyme inhibitor molecule provided by the invention has a bacterial inhibition effect, has an MurA enzyme inhibition effect, and also has an effect of interfering synthesis of bacterial cell walls.
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Paragraph 0039-0044

(2021/05/12)

STRONGLY LEWIS ACIDIC METAL-ORGANIC FRAMEWORKS FOR CONTINUOUS FLOW CATALYSIS
Lewis acidic metal-organic framework (MOF) materials comprising triflate-coordinated metal nodes are described. The materials can be used as heterogenous catalysts in a wide range of organic group transformations, including Diels-Alder reactions, epoxide-ring opening reactions, Friedel-Crafts acylation reactions and alkene hydroalkoxylation reactions. The MOFs can also be prepared with metallated organic bridging ligands to provide heterogenous catalysts for tandem reactions and/or prepared as composites with support particles for use in columns of continuous flow reactor systems. Methods of preparing and using the MOF materials and their composites are also described.
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Paragraph 0216-0219; 0223; 0239; 0255

(2021/02/26)

Imidazolium Triflate Ionic Liquid Improves the Activity of ZnCl2 in the Synthesis of Pyrroles and Ketones
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Nguyen, Hai Truong,Ngo, Dung Kim Thi,Chau, Khiem Duy Nguyen,Tran, Phuong Hoang
p. 157 - 165
(2021/03/16)

Preparation method of S-configuration phenyl ethyl amine hydrochloride compound
The invention relates to a preparation method of an S-configuration phenyl ethyl amine hydrochloride compound, and relates to the technical field of medicine synthesis and preparation. The preparationmethod comprises the following steps: (1) carrying out Friedel-Crafts reaction on m-dimethoxy benzene and acetyl chloride under the condition of Lewis acid to generate an intermediate A; (2) reactingthe intermediate A with hydroxylamine hydrochloride without separation to generate an intermediate B; (3) reducing the intermediate B under the condition of a reducing agent to obtain a compound C; (4) carrying out organic acid resolution on the compound C to obtain an S-configuration compound D organic salt; and (5) dissociating and salifying the organic salt to obtain a target product compoundE. The preparation method disclosed by the invention has the characteristics of simple purification, low cost, high efficiency, high yield and suitability for industrial mass production.
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Paragraph 0088-0090; 0100-0102; 0112-0114

(2021/03/11)

Trialkylammonium salt degradation: Implications for methylation and cross-coupling
Trialkylammonium (most notably N,N,N-trimethylanilinium) salts are known to display dual reactivity through both the aryl group and the N-methyl groups. These salts have thus been widely applied in cross-coupling, aryl etherification, fluorine radiolabelling, phase-transfer catalysis, supramolecular recognition, polymer design, and (more recently) methylation. However, their application as electrophilic methylating reagents remains somewhat underexplored, and an understanding of their arylation versus methylation reactivities is lacking. This study presents a mechanistic degradation analysis of N,N,N-trimethylanilinium salts and highlights the implications for synthetic applications of this important class of salts. Kinetic degradation studies, in both solid and solution phases, have delivered insights into the physical and chemical parameters affecting anilinium salt stability. 1H NMR kinetic analysis of salt degradation has evidenced thermal degradation to methyl iodide and the parent aniline, consistent with a closed-shell SN2-centred degradative pathway, and methyl iodide being the key reactive species in applied methylation procedures. Furthermore, the effect of halide and non-nucleophilic counterions on salt degradation has been investigated, along with deuterium isotope and solvent effects. New mechanistic insights have enabled the investigation of the use of trimethylanilinium salts in O-methylation and in improved cross-coupling strategies. Finally, detailed computational studies have helped highlight limitations in the current state-of-the-art of solvation modelling of reaction in which the bulk medium undergoes experimentally observable changes over the reaction timecourse. This journal is
Assante, Michele,Baillie, Sharon E.,Juba, Vanessa,Leach, Andrew G.,McKinney, David,Reid, Marc,Washington, Jack B.,Yan, Chunhui
p. 6949 - 6963
(2021/06/02)

A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for aerobic oxidation of alcohols
A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for the aerobic oxidation of alcohols has been developed for the first time, and the photoredox aerobic oxidation of secondary and primary alcohols provided the corresponding ketones and carboxylic acids, respectively, in high to excellent yields.
Zhu, Xianjin,Liu, Can,Liu, Yong,Yang, Haijun,Fu, Hua
p. 12443 - 12446
(2020/10/30)

Synthesis of acyclic and cyclic phosphonates based on substituted 2-hydroxybenzylic alcohols
A convenient synthesis of benzylic phosphonates and 2,3-dihydrobenzo[d][1,2]oxaphosphole 2-oxides substituted at the aromatic ring, as well as their precursors, 2-hydroxybenzylic alcohols, from the derivatives of salicylic aldehyde, salicylic acid, and 2-hydroxyacetophenone bearing an additional hydroxy or methoxy group at the para position of the aromatic ring was developed. For the first time, the possibility of selective demethylation of the methoxy group positioned ortho to the methylene phosphonate fragment with retention of the methoxy group at the para position was shown.
Brel, V. K.,Mikulenkova, E. A.,Mironov, V. F.,Tatarinov, D. A.,Terekhova, N. V.
p. 2147 - 2152
(2020/12/09)

Strongly Lewis Acidic Metal-Organic Frameworks for Continuous Flow Catalysis
The synthesis of highly acidic metal-organic frameworks (MOFs) has attracted significant research interest in recent years. We report here the design of a strongly Lewis acidic MOF, ZrOTf-BTC, through two-step transformation of MOF-808 (Zr-BTC) secondary building units (SBUs). Zr-BTC was first treated with 1 M hydrochloric acid solution to afford ZrOH-BTC by replacing each bridging formate group with a pair of hydroxide and water groups. The resultant ZrOH-BTC was further treated with trimethylsilyl triflate (Me3SiOTf) to afford ZrOTf-BTC by taking advantage of the oxophilicity of the Me3Si group. Electron paramagnetic resonance spectra of Zr-bound superoxide and fluorescence spectra of Zr-bound N-methylacridone provided a quantitative measurement of Lewis acidity of ZrOTf-BTC with an energy splitting (?E) of 0.99 eV between the ?x? and ?y? orbitals, which is competitive to the homogeneous benchmark Sc(OTf)3. ZrOTf-BTC was shown to be a highly active solid Lewis acid catalyst for a broad range of important organic transformations under mild conditions, including Diels-Alder reaction, epoxide ring-opening reaction, Friedel-Crafts acylation, and alkene hydroalkoxylation reaction. The MOF catalyst outperformed Sc(OTf)3 in terms of both catalytic activity and catalyst lifetime. Moreover, we developed a ZrOTf-BTC?SiO2 composite as an efficient solid Lewis acid catalyst for continuous flow catalysis. The Zr centers in ZrOTf-BTC?SiO2 feature identical coordination environment to ZrOTf-BTC based on spectroscopic evidence. ZrOTf-BTC?SiO2 displayed exceptionally high turnover numbers (TONs) of 1700 for Diels-Alder reaction, 2700 for epoxide ring-opening reaction, and 326 for Friedel-Crafts acylation under flow conditions. We have thus created strongly Lewis acidic sites in MOFs via triflation and constructed the MOF?SiO2 composite for continuous flow catalysis of important organic transformations.
Ji, Pengfei,Feng, Xuanyu,Oliveres, Pau,Li, Zhe,Murakami, Akiko,Wang, Cheng,Lin, Wenbin
supporting information
p. 14878 - 14888
(2019/10/02)

Enhanced Acidity and Activity of Aluminum/Gallium-Based Ionic Liquids Resulting from Dynamic Anionic Speciation
To explore if the catalytic activity of single-metal species in halometallate catalysts can be enhanced with mixed-metal species, aluminum and gallium were simultaneously introduced to prepare a mixed-metal ionic liquid (IL) through a one-pot reaction of [HN222]Cl, AlCl3, and GaCl3 in various amounts. The Lewis acidity in Friedel-Crafts acylation and alkylation reactions of these IL compositions were evaluated and all mixed-metal [HN222][xAlCl3 + (2 - x)GaCl3]Cl ILs exhibited higher catalytic activity than AlCl3, GaCl3, [HN222][Al2Cl7], or [HN222][Ga2Cl7]. The broadening in 27Al nuclear magnetic resonance (NMR) of these ILs indicates the presence of dynamic anionic species, whereas matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) and acetonitrile-probed Fourier transform infrared (FT-IR) analyses correlates the structure-activity relationship, for instance, identifying the presence of mixed-metal-containing [Cl2GaOClAlClOGaCl2]- species in the better-performing ILs.
Li, Kai,Choudhary, Hemant,Mishra, Manish Kumar,Rogers, Robin D.
p. 9789 - 9793
(2019/10/14)

A Ruthenium-Catalyzed C-H Activation Strategy as an Efficient Shortcut in the Total Synthesis of 6,8-Dimethoxy-1,3-dimethyl?-isoquinoline
A short and convenient total synthesis of 6,8-dimethoxy-1,3-dimethylisoquinoline, employing a C-H activation/alkenylation strategy, is reported. The approach involves the CeCl 3 7H 2 O-promoted methoximation of 2,4-dimethoxyacetophenone and a methoxime-directed ruthenium-catalyzed allylation. This was followed by a one-pot, ruthenium-catalyzed allyl to propenyl isomerization and a microwave-assisted 6π-azaelectrocylization to complete the sequence. This approach, which entails a shortcut in the synthetic management of the three-carbon side chain, is an improved and more efficient route toward the natural product, which facilitated its access in just three steps and 27.3percent overall yield.
Fonzo, Santiago,Kaufman, Teodoro S.,Vargas, Didier F.
p. 3908 - 3914
(2019/10/11)

Kolbe-Schmitt type reaction under ambient conditions mediated by an organic base
The combined use of an organic base for resorcinols realized a Kolbe-Schmitt type reaction under ambient conditions. When resorcinols (3-hydroxyphenol derivatives) were treated with DBU under a carbon dioxide atmosphere, nucleophilic addition to carbon dioxide proceeded to afford the corresponding salicylic acid derivatives in high yields.
Sadamitsu, Yuta,Okumura, Akira,Saito, Kodai,Yamada, Tohru
supporting information
p. 9837 - 9840
(2019/08/20)

A molybdenum based metallomicellar catalyst for controlled and chemoselective oxidation of activated alcohols in aqueous medium
A surfactant based oxodiperoxo molybdenum complex, which could activate molecular oxygen, has been employed as a catalyst for controlled oxidation of benzylic alcohols to corresponding carbonyls. The oxidation reactions were carried out under aqueous environment, however, in the absence of any extraneous base or co-catalyst. Sensitive/oxidizable functional groups like cyano, sulfide, hydroxyl, aryl-hydroxyl, alkene (internal/terminal), alkyne (internal/terminal), and acetal were tolerated during the transformations. Such selectivity is attributed to the mild nature of the catalyst. The methodology could also be scaled-up for multi-gram synthesis and the protocol is likely to find practical use since it requires an inexpensive recyclable-catalyst and easily available oxidant (under green conditions). A plausible mechanism is proposed with the help of preliminary computational study.
Thiruvengetam, Prabaharan,Chakravarthy, Rajan Deepan,Chand, Dillip Kumar
p. 123 - 133
(2019/07/19)

Hydrogen bond donor solvents enabled metal and halogen-free Friedel–Crafts acylations with virtually no waste stream
We have developed a metal and halogen-free Friedel–Crafts acylation protocol with virtually no waste stream generation. We propose a hydrogen bonding donor solvent will form a hydrogen bonding network and may provide significant rate enhancement for Friedel–Crafts reactions. Trifluoroacetic acid is one of the strongest H-bond donor solvents, which is also volatile and can be easily recovered by distillation without need for reaction workup. Our protocol is a ‘green’ Friedel–Crafts acylation process: 1) the catalyst can be recovered and reused; 2) using halogen free starting material (carboxylic acids anhydride or carboxylic acids); 3) no need for aqueous reaction work-up; 4) minimum or no waste steam generation.
Liu, Guangchang,Xu, Bo
supporting information
p. 869 - 872
(2018/02/09)

P -Selective (sp2)-C-H functionalization for an acylation/alkylation reaction using organic photoredox catalysis
p-Selective (sp2)-C-H functionalization of electron rich arenes has been achieved for acylation and alkylation reactions, respectively, with acyl/alkylselenides by organic photoredox catalysis involving an interesting mechanistic pathway.
Pandey, Ganesh,Tiwari, Sandip Kumar,Singh, Bhawana,Vanka, Kumar,Jain, Shailja
supporting information
p. 12337 - 12340
(2017/11/20)

A bactericide and its preparation method
The invention discloses a bactericide. The bactericide comprises the following components in parts by weight: 1 part of compound I, 4 parts of aluminum oxide hydroxide, 10 parts of boric acid and 100 parts of water, wherein the compound I is as shown in the specification. The preparation method of the compound I comprises the following steps: mixing a 2,4-resacetophenone and diazomethane ether mixed solution with boron fluoride etherate under the stirring effect of icy water, stirring about 0.2-1 hour, then carrying out backflow reaction for 5-7 hours, filtering after reaction, filtering, washing the obtained solid, drying, and recrystalizing so as to obtain an intermediate I, and reacting the intermediate I with 5-methyl-furan-2-formaldehyde so as to obtain an intermediate II; reacting the intermediate II with 4-sulfonamidophenylhydrazine so as to generate an intermediate III, and reacting the intermediate III with dichloromethane and boron tribromide so as to generate a target compound. The bactericide has the beneficial effects that a simple formula is adopted, and bacteria can be effectively killed.
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Paragraph 0015-0016

(2017/08/26)

Triazole derivative having HSP90 (Heat Shock Protein) inhibiting activity, as well as preparation method and application of triazole derivative
The invention discloses a triazole derivative having an HSP90 (Heat Shock Protein) inhibiting activity, as well as a preparation method and an application of the triazole derivative. Specifically, the invention relates to the triazole derivative having a structure as shown in a formula (I), a stereisomer of the triazole derivative and a pharmaceutically acceptable salt, wherein the definition of each substituent group in the formula (I) and the definition in a description are the same. The compound with a novel structure has the HSP90 inhibiting activity, can be used to cure cancers, neurodegenerative disorders, inflammation diseases, autoimmune diseases, ischemic brain injuries and the like, and has a broad application prospect.
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Paragraph 0125; 0131; 0132; 0133

(2017/08/02)

One-Step Dual Template Mediated Synthesis of Nanocrystalline Zeolites of Different Framework Structures
A novel, dual template mediated, one-step direct synthesis route is reported here for the preparation of nanocrystalline zeolites of different framework structures (such as ZSM-5, mordenite, and sodalite). In this synthesis strategy, a suitably designed dicationic/tetra-cationic soft template was used along with a conventional zeolite structure director to obtain nanocrystalline zeolites with nanosheet morphology. Nanocrystalline zeolites exhibited large surface area, pore volume, and intercrystalline mesopores. The long hydrophobic chain containing a multiammonium template cooperatively participates in the zeolite crystallization process along with a conventional microporous zeolite structure director to form the ultrathin microporous zeolite framework, while the hydrophobic interaction between the long chains restricted the excessive growth of zeolites and induced the formation of intercrystalline mesopores. Nanocrystalline zeolites exhibited exceptionally high activity in the acid-catalyzed reactions involving large molecules when compared with conventional zeolites. This synthesis strategy can be extended for the preparation of zeolites of different framework structures or other porous materials in the future.
Rani, Poonam,Srivastava, Rajendra,Satpati, Biswarup
p. 3323 - 3333
(2016/06/14)

A kind of compounds with analgesic effect and its preparation method (by machine translation)
This invention relates to a kind of compounds with analgesic effect and its preparation method, the structural formula of this compound as the following I, II, III or IV is shown, wherein R is the chemical formula is C n H 2n+1 straight chain alkyl, n=1-7. The invention also discloses the above-mentioned several kinds of different structural formula of compound preparation method, the preparation of the same and the application of the capsaicin receptor inhibitors. The present invention provides the compound has strong analgesic activity, more than du Lengding part, and pharmacological experiment has not found this compound has addiction side effects. The present invention provides the compound plus pharmaceutically acceptable vector can be prepared as pharmaceutical compositions and pharmaceutical preparation, and can be developed with the addiction of preparing a medicine analgesia class. (by machine translation)
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Paragraph 0040-0042

(2016/12/01)

Metal Sulfonate Polymers as Catalysts for the Heterogeneous Acylation of Aromatic Derivatives
A series of metal sulfonate salts attached to a poly(ether ether ketone) (PEEK) polymer were prepared by ultrasonic activation and then examined as heterogeneous catalysts in the Friedel–Crafts acylation of aromatic derivatives.
Morizur, Vincent,Hector, Daphné,Olivero, Sandra,Desmurs, Jean Roger,Du?ach, Elisabet
supporting information
p. 3126 - 3129
(2016/07/12)

Metal-Free Intermolecular Coupling of Arenes with Secondary Amides: Chemoselective Synthesis of Aromatic Ketimines and Ketones, and N-Deacylation of Secondary Amides
The direct transformation of common secondary amides into aromatic ketimines and aromatic ketones with C-C bond formation is described. The reaction can also be used for N-deacylation of secondary amides to release amines. This method consists of in situ amide activation with triflic anhydride and intermolecular capture of the resulting highly electrophilic nitrilium intermediate with an arene. The reaction is applicable to various kinds of secondary amides (electrophiles), but only electron-rich and moderately electron-rich arenes can be used as nucleophiles. Thanks to the use of bench stable arenes instead of reactive and basic organometallics as nucleophiles, the reaction proceeded with high chemoselectivity at the secondary amido group in the presence of a series of sensitive functional groups such as aldehyde, ketone, ester, cyano, nitro, and tertiary amido groups. The reaction can be viewed as a Friedel-Crafts-type reaction using secondary amides as acylating agents or as an intermolecular version of the Bischler-Napieralski reaction.
Huang, Pei-Qiang,Huang, Ying-Hong,Xiao, Kai-Jiong
p. 9020 - 9027
(2016/10/17)

Hexafluoro-2-propanol-Promoted Intermolecular Friedel-Crafts Acylation Reaction
The intermolecular Friedel-Crafts acylation was carried out in hexafluoro-2-propanol to yield aryl and heteroaryl ketones at room temperature without any additional reagents.
Vekariya, Rakesh H.,Aubé, Jeffrey
supporting information
p. 3534 - 3537
(2016/08/16)

Visible light mediated chemo-selective oxidation of benzylic alcohols
A highly chemoselective visible light mediated strategy has been developed for oxidation of benzylic alcohols. The method circumvents the use of toxic metal catalysts, high energy light source, and operates at room temperature. Furthermore reaction is easily scalable to gram levels.
Devari, Shekaraiah,Rizvi, Masood Ahmad,Shah, Bhahwal Ali
supporting information
p. 3294 - 3297
(2016/07/11)

Synthesis of industrially important aromatic and heterocyclic ketones using hierarchical ZSM-5 and Beta zeolites
Hierarchical ZSM-5 and Beta zeolites were investigated in the synthesis of wide range of industrially important aromatic/heterocyclic ketones by Friedel-Crafts acylation and benzoylation reactions. For comparative study, conventional ZSM-5 and Beta, and amorphous mesoporous Al-MCM-41 were investigated. Hierarchical zeolites were prepared by multi-ammonium structure directing agents whereas conventional zeolites were prepared by mono-ammonium structure directing agents. Among the catalysts investigated in this study, hierarchical Beta exhibited the highest reactant conversion in the acylation and benzoylation reactions. In this study, the systematic assessment of the catalytic activity of acid catalysts for wide range of aromatic and heterocyclic compounds is shown under one umbrella. To the best of our knowledge, these reactions over hierarchical zeolites (ZSM-5 and Beta) are reported here for the first time. Structure activity relationship is explained based on the physico-chemical properties, molecular size, reactivity of reactants, and reaction mechanism. Catalysts can be easily recovered and reused with negligible loss in the catalytic activity.
Kore, Rajkumar,Srivastava, Rajendra,Satpati, Biswarup
p. 129 - 141
(2015/09/28)

Catalysis of the acylation of aromatic derivatives by metallic tosylates
A series of metallic tosylates were prepared by ultrasonic metal activation and were further used as efficient catalysts for the acylation of aromatic derivatives.
Morizur, Vincent,Szafranek, Jessica,Bonhomme, Dominique,Olivero, Sandra,Desmurs, Jean Roger,Du?ach, Elisabet
p. 6813 - 6817
(2015/08/24)

Reactions of nitrilium salts with indole and pyrrole and their derivatives in the synthesis of imines, ketones and secondary amines
Abstract Reactions of N-methyl- and N-ethyl-nitrilium salts with indole and pyrrole and their derivatives yield imines or imine salts in good yields. The related imines are obtained from the salts after careful basification and hydrolysis of the imine salts or the imines by heating with aqueous base give the related ketones in good yields. Alternatively, the imine salts can be reduced using sodium borohydride in methanol to give the related secondary amines.
Giles, Robert G.,Heaney, Harry,Plater, M. John
p. 7367 - 7385
(2015/08/24)

Total synthesis of (±)-glabridin
An efficient formal synthesis of (±)-glabridin was accomplished in 10 steps from resorcinol using Raney Ni to reduce carbon-carbon double bonds in α,β-unsaturated carbonyl compound as the key step.
Ji, Wen-Hua,Gao, Qian-Shan,Lin, Yun-Liang,Gao, Hong-Mei,Wang, Xiao,Geng, Yan-Ling
p. 540 - 546
(2014/01/23)

Palladium(II)-catalyzed decarboxylative heck arylations of acyclic electron-rich olefins with internal selectivity
Despite the recent emergence of decarboxylative C-C bond forming reactions, methodologies providing internally arylated electron-rich olefins are still lacking. We herein report on palladium(II)-catalyzed decarboxylative Heck arylations of linear electron-rich olefins with excellent selectivity for the internal position. The method allows a variety of electron-rich linear olefins to undergo arylation with ortho-functionalized aromatic carboxylic acids, including heterocycles. The reaction mechanism has been explored with ESI-MS studies to confirm previous findings, and to reveal the formation of a highly stable palladium complex as a result of the Heck product reacting with the catalyst.
Fardost, Ashkan,Lindh, Jonas,Sjoeberg, Per J. R.,Larhed, Mats
p. 870 - 878
(2014/04/03)

Efficient and recyclable rare earth-based catalysts for Friedel-Crafts acylations under microwave heating: Dendrimers show the way
The catalytic system involving Sc(OTf)3 and a dendritic terpyridine ligand is able to promote the Friedel-Crafts acylation of a wide range of aromatics under microwave irradiation. The expected products are obtained in high yields after short reaction times and the nano-sized catalyst can be recovered and successfully used in 12 consecutive runs.
Perrier, Arnaud,Keller, Michel,Caminade, Anne-Marie,Majoral, Jean-Pierre,Ouali, Armelle
supporting information
p. 2075 - 2080
(2013/09/24)

Synthesis and cytotoxicity of novel (thiazol-2-yl)hydrazine derivatives as promising anti-Candida agents
Thirty-eight new (4-(4-substituted-phenyl/2,4-disubstituted-phenyl)- thiazol-2-yl)hydrazine derivatives were synthesized in good yield and assayed for their in vitro anti-Candida activity, compared to topical and systemic antifungal drugs, against twenty-two clinical isolates of Candida spp. The concurrent presence of aliphatic chains or cycloaliphatic rings at N1-hydrazine and a 4-methyl/4-methoxyphenyl at C4 position of the thiazole nucleus exhibited an interesting anti-Candida inhibitory activity. Moreover, some of the most active compounds showed synergistic antifungal effects and lower cell toxicity when combined with clotrimazole.
Carradori, Simone,Secci, Daniela,Bolasco, Adriana,Rivanera, Daniela,Mari, Emanuela,Zicari, Alessandra,Lotti, Lavinia Vittoria,Bizzarri, Bruna
p. 102 - 111
(2013/10/01)

Friedel-Crafts acylation using bismuth triflate in [BMI][PF6]
Bismuth trifluoromethanesulfonate was found to be a good catalyst for the Friedel-Crafts acylation. Bismuth triflate immobilized in an ionic liquid was the most efficient catalytic system. Bismuth triflate in [BMI][PF6] catalyzes this reaction under microwave irradiation allowing the rapid synthesis of aryl ketones in excellent yields. The catalyst system was easily recovered and reused several times.
Tran, Phuong Hoang,Duus, Fritz,Le, Thach Ngoc
experimental part
p. 222 - 224
(2012/01/30)

Acylation of aromatic ethers using different carboxylic acid anhydrides as acylating agents in the presence of nontoxic, noncorrosive resin amberlyst 15 as a solid acid catalyst
Friedel-Crafts acylation of aromatic ethers, anisole, 2-methoxynaphthalene, and dimethoxybenzenes with different acid anhydrides is carried out in the presence of an inexpensive and nonhazardous solid acid, Amberlyst 15. The catalyst is reusable, thus making the process environmentally friendly.
Pande, Manoj A.,Samant, Shriniwas D.
experimental part
p. 754 - 761
(2011/04/12)

Solid-supported Pd(0): An efficient heterogeneous catalyst for aerobic oxidation of benzyl alcohols into aldehydes and ketones
Solid-supported nano- and microparticles of Pd(0) (SS-Pd) were used as heterogeneous catalysts for aerobic oxidation of benzyl alcohols. Primary and secondary benzyl alcohols gave the corresponding products in good yields. In addition, the catalysts could be reused up to five runs without significant loss of activities.
Bandna,Aggarwal, Nidhi,Das, Pralay
supporting information; experimental part
p. 4954 - 4956
(2011/10/08)

Total synthesis, antiprotozoal and cytotoxicity activities of rhuschalcone VI and analogs
The total synthesis of a potent antiplasmodial natural bichalcone, rhuschalcone VI, is described starting from simple and available resorcinol and 4-hydroxybenzaldehyde. Key steps include the solvent-free Aldol syntheses of chalcones, and the successful application of the Suzuki-Miyaura coupling reaction in the synthesis of bichalcones. The present work constitutes a general method for the rapid syntheses of a number of bichalcones related to rhuschalcone VI. Some of the bichalcones showed moderate antiprotozoal activities against Bodo caudatus, a preliminary screening system for antitrypanosomal activities, most of them with little or no cytotoxicity.
Mihigo, Shetonde O.,Mammo, Wendimagegn,Bezabih, Merhatibeb,Andrae-Marobela, Kerstin,Abegaz, Berhanu M.
scheme or table
p. 2464 - 2473
(2010/07/02)

Synthesis of aryl ketones by palladium(II)-catalyzed decarboxylative addition of benzoic acids to nitriles
An efficient, sustainable method for the preparation of aryl ketones from ortho-substituted benzoic acids proceeds through their decarboxylation to generate an aryl-palladium species, followed by addition to a nitrile and hydrolysis of the intermediate ketimine.
Lindh, Jonas,Sjoeberg, Per J. R.,Larhed, Mats
supporting information; experimental part
p. 7733 - 7737
(2011/01/05)

Recyclable hafnium(IV) bis(perfluorooctanesulfonyl)amide complex for catalytic Friedel-Crafts acylation and Prins reaction in fluorous biphase system
In fluorous biphase system, hafnium(IV) bis(perfluorooctanesulfonyl)amide complex (Hf[N(SO2C8F17)2]4) was found to be a highly reactive and recyclable Lewis acid catalyst for Friedel-Crafts acylation and Prins reaction at significantly low catalyst loadings (≤1 mol%). In these reactions, Hf[N(SO2C8F17)2]4 is selectively soluble in the lower fluorous phase and can be recovered simply by phase separation. Furthermore, the catalyst can be reused without decrease of activity.
Hao, Xiuhua,Yoshida, Akihiro,Hoshi, Nobuto
p. 1396 - 1401
(2008/09/18)

Miscrowave-assisted efficient synthesis of polymethoxyacetophenones and natural polymethoxyflavones, and thier inhibitory effects on melanogenesis
Microwave, assisted Friedel-Crafts acetylation of polymethoxybenzenes with acetic anhydride in the presence of In(CF3SO3)3 under solvent-free conditions was achieved rapidly to give polymethoxyacetophenones in high yields. Microwave-assisted benzoylation of 2'-hydroxypolymethoxyacetophenones with polymethoxybenzoyl chlorides, followed by the rearrangement of the resulting benzoates and the final formation of natural polymethoxyflavones was achieved rapidly and efficiently. The polymethoxyflavones showed inhibitory effects on melanogenesis in human melanoma cells.
Tsukayama, Masao,Kusunoki, Eiji,Hossain, Mohammad M.,Kawamura, Yasuhiko,Hayashi, Shinji
p. 1589 - 1600
(2008/09/17)

Hf[N(SO2C8F17)2] 4-catalyzed Friedel-Crafts acylation in a fluorous biphase system
In a fluorous biphase system, Hf[N(SO2C8F 17)2]4 complex (1 mol %) catalyzes Friedel-Crafts acylation of aromatic compounds such as anisole, toluene and chlorobenzene, and the corresponding aromatic ketones are obtained in satisfactory to high yields. The catalyst is selectively soluble in lower fluorous phase and can be easily recovered by simple phase separation. Furthermore, the catalyst can be reused without decrease of activity in most cases.
Hao, Xiuhua,Yoshida, Akihiro,Nishikido, Joji
p. 2697 - 2700
(2007/10/03)

Catalytic Friedel-Crafts acylation of aromatic ethers using Sml3
10% mol Sml3 catalysed the Friedel-Crafts acylation of aromatic ethers by acyl chlorides in acetonitrile with the yields of 48-82%. Reactions of various substituted aromatic ethers with acyl chloride were studied. The structures of compounds were established by IR and 1H NMR. The main product obtained with anisole is the para-substituted compound with only a trace (3, a pattern repeated with the other aromatic ethers used.
Chen, Xiaohang,Yu, Mingxin,Wang, Meijun
p. 80 - 81
(2007/10/03)

The methoxycarbonylation of aryl chlorides catalysed by palladium complexes of bis(di-tert-butylphosphinomethyl)benzene
A catalyst system based on palladium-1,2-bis-(di-tert-butylphosphinomethyl) benzene (BDTBPMB) shows good activity for the methoxycarbonylation of strongly activated aryl chlorides, like 4-chloromethylbenzoate or 4-chlorocyanobenzene. Surprisingly, the use of less activated aryl chlorides, like 4-chloroacetophenone, leads to the formation of dimethyl terephthalate amongst other products arising from organic reactions of methoxide ion and/or CO. Less nucleophilic alcohols such as 2,2,2-trifluoroethanol promote the formation of carbonylation products even from 4-chloroacetophenone and chlorobenzene. Labelling studies involving CD3OH, CD3OD or 13CO give information on the origin of many of the products. The Royal Society of Chemistry 2005.
Jimenez-Rodriguez, Cristina,Eastham, Graham R.,Cole-Hamilton, David J.
p. 1826 - 1830
(2007/10/03)

Niobium pentachloride-silver perchlorate as an efficient catalyst in the Friedel-Crafts acylation and Sakurai-Hosomi reaction of acetals
Friedel-Crafts acylation catalyzed by niobium pentachloride with silver salt is described. Aromatic compounds with Ac2O or Bz2O were smoothly converted into the corresponding ketones in good to excellent yields. This system was also applied to the Sakurai-Hosomi reaction using acetals. The reaction proceeded quite rapidly to give the desired products in excellent yields.
Arai, Shigeru,Sudo, Yukinori,Nishida, Atsushi
p. 4639 - 4642
(2007/10/03)

Chalcones as potent tyrosinase inhibitors: The importance of a 2,4-substituted resorcinol moiety
Chalcones with tetra-substituted hydroxyl groups were synthesized and tested as tyrosinase inhibitors towards designing novel whitening agents, resulting with the most potent inhibitor, with IC50 of 0.02 μM concn. Compounds, which inhibit tyrosinase, could be effective as depigmenting agents. We have introduced a group of mono-, di-, tri- and tetra-substituted hydroxychalcones as effective tyrosinase inhibitors, showing that the most important factor determining tyrosinase inhibition efficiency is the position of the hydroxyl group(s) rather their number. The aim of the present study was to investigate the contribution of the different functional groups of the tetrahydroxychalcones to their inhibitory potency, with a view to optimizing the design of whitening agents. Four tetrahydroxychalcones were evaluated, the commercially available Butein and other three were synthesized, and their inhibitory effect on tyrosinase was tested. Results showed that a 2,4-substituted resorcinol subunit on ring B contributed the most to inhibitory potency. Changing the resorcinol substitute to position 3,5- or placing it on ring A significantly diminished the inhibitory effect of the compounds. A catechol subunit on ring A acted as a metal chelator (in the presence of copper ions) and as a competitive inhibitor (in the presence of tyrosinase), while a catechol on ring B oxidized to o-quinone (in the presence of both copper ions and tyrosinase). Three of the compounds also demonstrated antioxidant activity, which may contribute to the prevention of pigmentation. An examination of correlations between inhibitory activity and physical properties of the chalcones tested (such as dissociation energy and molecular planarity) showed positive correlation with the moment dipole value in the Y-axis, which may be used as an indicator of the inhibitory potential of new molecules. The present study revealed two very active tyrosinase inhibitors, 2,4,3′,4′- hydroxychalcone and 2,4,2′,4′-hydroxychalcone (with IC50 of 0.2 and 0.02 μM, respectively). Structure-related activity studies added some understanding of the role and contribution of different functional groups associated with tyrosinase inhibitors.
Khatib, Soliman,Nerya, Ohad,Musa, Ramadan,Shmuel, Maayan,Tamir, Snait,Vaya, Jacob
p. 433 - 441
(2007/10/03)

Aluminum dodecatungstophosphate (AlPW12O40) as a non-hygroscopic Lewis acid catalyst for the efficient Friedel-Crafts acylation of aromatic compounds under solvent-less conditions
Stable and non-hygroscopic aluminum dodecatungstophosphate (AlPW 12O40), which is prepared easily from cheap and commercially available compounds was found to be an effective catalyst for Friedel-Crafts acylation reactions using carboxylic acids, acetic anhydride and benzoyl chloride in the absence of solvent under mild reaction conditions.
Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad
p. 10843 - 10850
(2007/10/03)

N,N-Dibromobenzenesulfonamide as a reagent for oxidative cleavage of oximes to their parent carbonyl compounds under non-aqueous and aprotic conditions
Deprotection of different oximes to their parent aldehydes and ketones in high yields has been carried out by using N,N-dibromobenzenesulfonamide(dibromoamine-b) under mild conditions.
Tajbakhsh, Mahmood,Khazaei, Ardeshir,Shabani-Mahalli, Majid,Ghorbani-Vaghei, Ramin
p. 141 - 142
(2007/10/03)

Deoximation with N-bromosulfonamides
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Tajbaksh,Khazaei,Shabani Mahalli,Ghorbani Vaghei
p. 1053 - 1054
(2007/10/03)

O-Methylation of phenolic compounds with dimethyl carbonate under solid/liquid phase transfer system
The industrially important alkyl aryl ethers, of which anisole is the simplest form, can be synthesized by reacting the corresponding phenols with the environmentally benign dimethyl carbonate (DMC). The reaction is carried out under mild conditions of temperature and pressure. Excellent yields and selectivity of product were obtained after a few hours of reaction.
Ouk, Samedy,Thiebaud, Sophie,Borredon, Elisabeth,Legars, Pierre,Lecomte, Lo?c
p. 2661 - 2663
(2007/10/03)

Friedel-crafts reactions catalyzed by rare earth metal trifluoromethanesulfonates
Rare earth metal trifluoromethanesulfonates (rare earth metal trifiates, RE(OTf)3) were found to be efficient catalysts for Friedel-Crafts acylation and alkylation. In the presence of a catalytic amount of RE(OTf)3, acylation of aromatic compounds having electron-donating substituents such as anisole, thioanisole, and mesitylene with acid anhydrides proceeded smoothly to afford the corresponding aromatic ketones in high yields. Although RE(OTf)3 alone is not effective for acylation of less reactive aromatics such as toluene, the combination of RE(OTf)3 and lithium perchlorate (LiClO4) enhanced the catalytic activity dramatically. Friedel-Crafts acylation reactions using rare earth metal perfluoroalkanesulfonates were also successfully performed in supercritical carbon dioxide (scCO2). Moreover, in the presence of a catalytic amount of RE(OTf)3, aromatic compounds reacted with benzyl chloride smoothly to afford the corresponding alkylation products in high yields. In these reactions, RE(OTf)3 could be easily recovered after the reactions were completed and could be reused without loss of activity.
Kawada, Atsushi,Mitamura, Shuichi,Matsuo, Jun-Ichi,Tsuchiya, Takehiro,Kobayashi, Shu
p. 2325 - 2333
(2007/10/03)

The reduction of α-X-acetophenones (X = PhO, Br, Cl) in hydrogendonating solvents at elevated temperatures
The reduction of α-X-acetophenones (X = PhO, Br, Cl), as model compounds for lignin liquefaction studies, has been investigated in the presence of a hydrogen-donating solvent such as 9,10-dihydroanthracene (AnH2) or 2-propanol, between 373 and 573 K. With α-phenoxyacetophenone (PAP) in AnH2, acetophenone and phenol have been obtained with high selectivities. The mechanism involves the reverse radical disproportionation (RRD) with AnH2. Hydrodebromination of α-bromoacetophenone (BrAP) is quantitative at 423 K using AnH2 as a reducing agent. Now, the hydrogen transfer proceeds by an uninhibited radical chain mechanism with anthracenyl radicals as the chain carriers. For the kinetic analysis, the C-X (X = Br, Cl) bond dissociation enthalpies (BDEs) have been determined by means of very low pressure pyrolysis to give BDE(C-Br) = 271 kJ mol-1 and, as a lower limit, BDE(C-Cl) ? 309 kJ mol-1, at 298 K. The BDEs are quite at variance with recently published insights derived from an electrochemical study. For comparison, density functional theory calculations (DFT) have been performed.
Dorrestijn, Edwin,Hemmink, Sven,Hulstman, Guido,Monnier, Laurent,Van Scheppingen, Wibo,Mulder, Peter
p. 607 - 616
(2007/10/03)

Facile transformation of N,N-dimethylhydrazones and tosylhydrazones to ketones with dimethylsulfate and potassium carbonate
N,N-Dimethylhydrazones and tosylhydrazones can be converted to their ketones in good to excellent yields with dimethylsulfate and K2CO3.
Kamal, Ahmed,Arifuddin,Rao, N. Venugopal
p. 3927 - 3931
(2007/10/03)

Media controlled photo - Favorskii type rearrangement of α-chloro acetophenones: Synthesis of phenylacetic acids
Photolysis of substituted α-chloro acetophenones has been studied in different solvent systems wherein 1,2-aryl migration is found to be media controlled. Effect of substituents on the migratory aptitude and a direct access to phenylacetic acids, in practical yields, has been described.
Dhavale, Dilip D.,Mali, Vasant P.,Sudrik, Surendra G.,Sonawane, Harikisan R.
p. 16789 - 16794
(2007/10/03)