101-41-7Relevant articles and documents
Solvent-modulated chemoselective deprotections of trialkylsilyl esters and chemoselective esterifications
Lee, Adam Shih-Yuan,Su, Feng-Yih
, p. 6305 - 6309 (2005)
A series of trialkylsilyl esters were deprotected or transesterificated into their corresponding carboxylic acids or methyl esters under a catalytic amount of CBr4 in alcohol reaction system. This method enables to desilylate secondary sp3-carbon, sp2-carbon, sp-carbon and aryl tethered trialkylsilyl esters to carboxylic acids, whereas primary sp 3-carbon tethered trialkylsilyl esters were further converted into their methyl esters under CBr4/MeOH reaction conditions. The highly chemoselective deprotections can be modulated and achieved by the introduced protecting trialkylsilyl groups and the used alcohols such as MeOH and EtOH under this photochemically-induced reaction conditions.
Synthesis of Benzo[a]carbazoles and an Indolo[2,3-a]carbazole from 3-Aryltetramic Acids
Truax, Nathanyal J.,Banales Mejia, Fernando,Kwansare, Deborah O.,Lafferty, Megan M.,Kean, Maeve H.,Pelkey, Erin T.
, p. 6808 - 6815 (2016)
A simple and flexible approach to 3-pyrrolin-2-one fused carbazoles is disclosed. The key step involves the BF3-mediated electrophilic substitution of indoles with N-alkyl-substituted 3-aryltetramic acids, which provides access to indole-substituted 3-pyrrolin-2-ones. Scholl-type oxidative cyclizations of these materials led to the formation of the corresponding 3-pyrrolin-2-one-fused benzo[a]carbazoles and indolo[2,3-a]carbazoles. This work represents the first synthesis of the benzo[a]pyrrolo[3,4-c]carbazol-3(8H)-one ring system, while the indolo[2,3-a]pyrrolo[3,4-c]carbazol-5-one ring system is found in a number of biologically active compounds including the protein kinase C (PKC) inhibitor, staurosporine.
Secondary metabolites by chemical screening, 39: Acyl α-L- rhamnopyranosides, a novel family of secondary metabolites from streptomyces sp.: Isolation and biosynthesis
Grond, Stephanie,Langer, Hans-Jo?rg,Henne, Petra,Sattler, Isabel,Thiericke, Ralf,Grabley, Susanne,Za?hner, Hans,Zeeck, Axel
, p. 929 - 937 (2000)
In the course of our chemical screening program, the novel acyl α-L- rhamnopyranosides (1-6) were detected as metabolites from five different strains of Streptomycetes. The structures of all these compounds were elucidated by chemical and spectroscopic methods. The biosynthesis of 1 and 3 was established by feeding 13C-labelled acetate, glycerol, and d-glucose to Streptomyces griseoviridis (strain Tu 3634), and resulted in a complete labelling pattern of the 2,4-dimethyl-3-furanylcarbonyl and benzoyl residues, as well as the rhamnose moiety. These results reveal biosynthetic pathways of general importance and give an insight into the generation of the hexose phosphates, from which deoxysugars are formed. The acyl rhamnosides are members of a novel family of microbial metabolites and are considered as rhamnoconjugates from Streptomycetes.
Three-component coupling reaction of benzylic halides, carbon dioxide, and N,N-dimethylformamide by using paired electrolysis: Sacrificial anode-free efficient electrochemical carboxylation of benzylic halides
Senboku, Hisanori,Nagakura, Kotaro,Fukuhara, Tsuyoshi,Hara, Shoji
, p. 3850 - 3856 (2015)
Sacrificial anode-free efficient electrochemical carboxylation of benzylic halides was successfully performed by using a paired electrolysis protocol. Constant-current electrolysis of a DMF solution of benzylic halides in the presence of carbon dioxide using a one-compartment cell equipped with a Pt plate cathode and a Pt wire anode (quasi-divided cell) resulted in efficient three-component coupling reaction of benzylic halides, carbon dioxide and DMF to yield N-methyl-N-(phenylacetoxy)methylformamides, as carboxylated coupling products, in good yields.
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Cowell,A.,Stille,J.K.
, p. 4193 (1980)
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PAH-supported tin hydride: A new tin reagent easily removable from reaction mixtures
Gastaldi, Stéphane,Stien, Didier
, p. 4309 - 4311 (2002)
We demonstrate here that a new pyrene-supported tin hydride can be used in radical chemistry. Final products were easily purified by adsorption of the PAH-supported tin side product with activated carbon.
Chemistry of palladium phosphinite (PPh2(OR)) and phosphonite (P(OPh)2(OH)) complexes: Catalytic activity in methoxycarbonylation and Heck coupling reactions
Pryjomska, Iweta,Bartosz-Bechowski, Hubert,Ciunik, Zbigniew,Trzeciak, Anna M.,Ziolkowski, Jozef J.
, p. 213 - 220 (2006)
The new phosphinite and phosphonite complexes (1-8) are very efficient catalysts for the methoxycarbonylation of iodobenzene and Heck cross-coupling of bromobenzene with butyl acrylate. High catalytic activity of these complexes can be explained by their in situ transformations during the reaction, stimulated by the presence of water, acid (HCl) or base (NEt3). Hydrolysis of phosphinite palladium complexes of the form trans-PdCl 2[PPh2(OR)]2 (R = C6F5 2, tBu 3, or O-menthyl 4) results in the formation of the dimeric complex [μ-ClPd(PPh2OH)(PPh2O)]2 5, which is deprotonated by NEt3, producing a polymeric complex of formula [Pd(P(O)PPh2)2]n 8. The reverse reaction, protonolysis of 8 with HCl, leads back to 5 and the monomeric complex 5a. The phosphinite complex PdCl2[PPh2(OBu)]2 1 with a more lipophilic ligand, PPh2(OBu), does not undergo hydrolysis under the same conditions. In the reaction of PdCl2(cod) with P(OPh) 2(OH), the new dimer [μ-ClPd(P(OPh)2OH)(P(OPh) 2O)]2 6 was obtained, whereas reaction of Pd(OAc) 2 with P(OPh)2(OH) leads to the polymeric complex [Pd[P(O)(OPh)2]2]n 7. Protonolysis of 7 with HCl results in the formation of 6. The Royal Society of Chemistry 2006.
Role of Arabidopsis INDOLE-3-ACETIC ACID CARBOXYL METHYLTRANSFERASE 1 in auxin metabolism
Takubo, Eiko,Kobayashi, Makoto,Hirai, Shoko,Aoi, Yuki,Ge, Chennan,Dai, Xinhua,Fukui, Kosuke,Hayashi, Ken-ichiro,Zhao, Yunde,Kasahara, Hiroyuki
, p. 1033 - 1038 (2020)
The phytohormone auxin regulates a wide range of developmental processes in plants. Indole-3-acetic acid (IAA) is the main auxin that moves in a polar manner and forms concentration gradients, whereas phenylacetic acid (PAA), another natural auxin, does not exhibit polar movement. Although these auxins occur widely in plants, the differences between IAA and PAA metabolism remain largely unknown. In this study, we investigated the role of Arabidopsis IAA CARBOXYL METHYLTRANSFERASE 1 (IAMT1) in IAA and PAA metabolism. IAMT1 proteins expressed in Escherichia coli could convert both IAA and PAA to their respective methyl esters. Overexpression of IAMT1 caused severe auxin-deficient phenotypes and reduced the levels of IAA, but not PAA, in the root tips of Arabidopsis, suggesting that IAMT1 exclusively metabolizes IAA in vivo. We generated iamt1 null mutants via CRISPR/Cas9-mediated genome editing and found that the single knockout mutants had normal auxin levels and did not exhibit visibly altered phenotypes. These results suggest that other proteins, namely the IAMT1 homologs in the SABATH family of carboxyl methyltransferases, may also regulate IAA levels in Arabidopsis.
Esterification of carboxylic acids with boron trichloride
Dyke, Christopher A.,Bryson, Thomas A.
, p. 3959 - 3961 (2001)
Treatment of carboxylic acids with boron trichloride followed by addition of alcohol provides the carboxylic ester. This esterification, following BCl3 ether or ester O-C cleavage reaction conditions, proceeds cleanly in good yields with most substrates. Cleavage of benzyl esters with boron trichloride then treating with methanol affords the methyl ester.
Sodium bis(2-methoxyethoxy)aluminium hydride in petroleum ether; a reagent for the selective reduction of brominated fatty esters to bromo alcohols
Wells, Andy
, p. 1143 - 1147 (1996)
The combination of NaH2Al(OCH2CH2OMe)2/petroleum ether was found to be highly effective for the selective reduction of long chain esters to alcohols in the presence of alkyl bromides.
Alkynolate Anions via a New Rearrangement: The Carbon Analogue of the Hofmann Reaction
Kowalski, Conrad J.,Fields, Kevin W.
, p. 321 - 323 (1982)
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MICROBIAL HYDROLYSIS AS A POTENT METHOD FOR THE PREPARATION OF OPTICALLY ACTIVE NITRILES, AMIDES AND CARBOXYLIC ACIDS
Kakeya, Hideaki,Sakai, Naoko,Sugai, Takeshi,Ohta, Hiromichi
, p. 1343 - 1346 (1991)
Many kinds of aromatic nitriles have been hydrolyzed to afford the corresponding amides and carboxylic acids, by the aid of enzyme system of Rhodococcus butanica.This enzymatic hydrolysis can be successfully applied to the kinetic resolution of α-arylpropionitriles, resulting in the formation of (R)-amides and (S)-carboxylic acids.
Design of polyaromatic hydrocarbon-supported tin reagents: A new family of tin reagents easily removable from reaction mixtures
Stien, Didier,Gastaldi, Stephane
, p. 4464 - 4470 (2004)
We report in this paper the preparation and use of stannanes 11, 12a, and 12b, compounds whose 3-pyrenylpropyl side chain affinity for activated carbon simplifies tin removal and product isolation. Our pyrene-supported reagents can be used for radical reductions and cyclizations (11), radical and cationic allylations (12a), and Stille couplings (12b) in much the same way as tributyltin derivatives.
A Simple and Efficient Procedure for Transesterification Catalyzed by Indium Triiodide
Ranu, Brindaban C.,Dutta, Pinak,Sarkar, Arunkanti
, p. 6027 - 6028 (1998)
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Selective mono-C-methylations of arylacetonitriles and arylacetates with dimethylcarbonate: A mechanistic investigation
Tundo, Pietro,Selva, Maurizio,Perosa, Alvise,Memoli, Sofia
, p. 1071 - 1077 (2002)
The very high mono-C-methylation selectivity (>99%) of arylacetic acid derivatives (ArCH2X; X = CN, CO2Me) with dimethyl carbonate (DMC) is due to a mechanism that involves consecutive methoxycarbonylation, methylation, and demethoxycarbonylation steps. Important aspects of this mechanism are clarified herein by a kinetic investigation. In the case of arylacetonitriles, at 140°C, the comparison of the rate constants of model reactions involving 2-phenyl propionitrile, phenylacetonitrile, 2-methoxycarbonylphenylacetonitrile, and 2-methyl-2-methoxy carbonylphenyl acetonitrile (compounds 1a-4a, respectively) with DMC indicates that the methylation process is the fastest and the irreversible step, which drives the overall reaction to completion. The situation is reversed for arylacetic esters, where the methylation is more difficult than the demethoxycarbonylation reaction; therefore, a higher reaction temperature is required.
Design, synthesis, and in vitro evaluation of novel 1,3,4-oxadiazolecarbamothioate derivatives of Rivastigmine as selective inhibitors of BuChE
Fallah, Akram,Mohanazadeh, Farajollah,Safavi, Maliheh
, p. 341 - 355 (2020)
Rivastigmine has been prescribed for the therapy of Alzheimer’s disease (AD) symptoms. This drug is classified in the carbamate derivative group that has dual activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). According to the structure of Rivastigmine and its performance, a new series of 5-aryl-1,3,4-oxadiazole-2-carbamothioate compounds I–XI was synthesized using structure-based drug discovery approaches. For this purpose a set of these compounds were designed with computational docking method and their interactions with amino acid residues in the active sites of AChE and BuChE checked out. The structures of synthesized compounds were established by physicochemical and spectroscopic methods. The carbamoyl moiety of Rivastigmine structure was modified to carbamothioate and the effects of 1,3,4-oxadiazole heterocycle as a pharmacophoric nucleus were investigated. The potential of the synthesized compounds I–XI was evaluated against two most known agents of AD (AChE and BuChE) to determine their IC50 values. The results of the docking showed the range of binding affinity for the best poses of ten individual conformers for any compounds (I–XI) was between ?7.81 (VI) and ?6.75 (II) kcal/mol. The results of biological experiments displayed that most synthetic compounds (I–VIII) showed moderate to excellent selective activity range against BuChE (0.51–69.44 μM). In vitro cytotoxicity evaluation of these compounds (I–XI) by MTT assay on human dermal fibroblast (HDF) cell line exhibited no activity against HDF. The compound VI [S-(5-(p-tolyl)-1,3,4-oxadiazol-2-yl) ethyl(methyl)carbamothioate] showed the most stable binding affinity (?7.81 kcal/mol) and the lowest IC50 value (0.51 μM) in comparison with Rivastigmine with 7.72 μM and Donepezil with 5.20 μM against BuChE.
Conversion of phenylacetonitrile in supercritical alcohols within a system containing small volume of water
Hou, Zhi-Qiang,Zhang, Rui-Zhe,Luo, Li-Gang,Yang, Jing,Liu, Chun-Ze,Wang, Yuan-Yuan,Dai, Li-Yi
, p. 490 - 494 (2015)
The reaction of phenylacetonitrile in supercritical methanol and ethanol in a system containing a small volume of water was studied. The effects of various operating conditions, such as reaction temperature, reaction time, the mole ratio of phenylacetonitrile/water/methanol or ethanol on the product yield were systematically investigated. The optimal yield of methyl phenylacetate for phenylacetonitrile in supercritical methanol in a system containing a small volume of water was 70 % at 583 K and 2.5 h. The optimal yield of ethyl phenylacetate for phenylacetonitrile in supercritical ethanol with a small volume of water was 80 % at 583 K and 1.0 h. At the same time, a feasible mechanism was proposed for phenylacetonitrile in supercritical methanol and ethanol in a system containing a small volume of water.
Catalytic Uses of Fe(CO)5: Formation of Carboxylic Acid Derivatives
Tustin, Gerald C.,Hembre, Robert T.
, p. 1761 - 1764 (1984)
Carboxylic acid derivatives were prepared by carbonylating an alkyl or aralkyl halide in the presence of a catalytic amount of iron carbonyl, a base, and an alcohol or water.
Collignon
, p. 139,141 (1975)
Use of Phosphorus Pentoxide: Esterification of Organic Acids
Banerjee, Amalendu,Sengupta, Saumitra,Adak, Mohini Mohan,Banerjee, Gopal Chandra
, p. 3106 - 3108 (1983)
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Chemoselective protection of carboxylic acid as methyl ester: A practical alternative to diazomethane protocol
Chakraborti, Asit K.,Basak, Anindita,Grover, Vikas
, p. 8014 - 8017 (1999)
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Silica Chloride: A Versatile Heterogeneous Catalyst for Esterification and Transesterification
Srinivas,Mahender,Das, Biswanath
, p. 2479 - 2482 (2003)
Silica chloride has been found to be an efficient catalyst for esterification of carboxylic acids (aliphatic, aromatic and conjugated) with alcohols (primary, secondary and tertiary) as well as for transesterification of esters (by both alcoholysis and acidolysis).
W(CO)6 Mediated C-S Bond Cleavage Reactions
Ng, Chi Tat,Wang, Xiaojun,Luh, Tien-Yau
, p. 2536 - 2539 (1988)
W(CO)6-mediated reactions of thioethers in refluxing chlorobenzene yielded mainly the corresponding dimers.Optically active thioethers give the respective racemic products.Mercaptans, on the other hand, predominantly afford the corresponding reduced products.A deuterium labeling experiments suggest that the SH group is the hydrogen source in the latter reduction reactions.A free-radical mechanism is suggested.
Chemoselective nucleophilic arylation and single-step oxidative esterification of aldehydes using siloxanes and a palladium-phosphinous acid as a reaction switch
Lerebours, Rachel,Wolf, Christian
, p. 13052 - 13053 (2006)
Aldehydes and siloxanes form methyl esters in a single step through mild oxidative esterification in the presence of a palladium catalyst or, alternatively, afford secondary alcohols via TBAF-promoted arylation in the absence of a catalyst at increased temperatures under otherwise identical reaction conditions. Copyright
A Simple, efficient, green, cost effective and chemoselective process for the esterification of carboxylic acids
Rekha,Ramani, Modukuri V.,Ratnamala,Rupakalpana, Vempati,Subbaraju, Gottumukkala V.,Satyanarayana, Chava,Rao, C. Someswara
, p. 769 - 773 (2009)
Carboxylic acids have been esterified under mild and solvent-free conditions in high yield and purity using the green reagents, dimethyl carbonate and diethyl carbonate, under acid catalysis. The present methodology is free of the disadvantages of base catalysis described earlier, such as high temperatures, use of autoclaves, use of the expensive DBU as base in stoichiometric amounts and the carbonate as solvent. High chemoselectivity is observed in the case of hydroxybenzoic acids.
Electrocatalytic carboxylation of halogenated compounds with mesoporous silver electrode materials
Jiang, Cheng-Jie,Liu, Yu-Ting,Lu, Jia-Xing,Shan, Si-Li,Wang, Huan,Zhang, Jing-Jie
, p. 21986 - 21990 (2021/07/02)
Mesoporous silver materials are used as electrocatalysts for halogenated compounds. The mesoporous silver materials have uniform mesoporous size (8 nm), large specific surface area (12 m2g?1), high pore volume (0.07 cm3g?1), and a good 3D network structure of the metallic silver skeleton. The results show that the prepared materials exhibit high performance in electrocatalytic carboxylation of halogenated compounds to acid (78%).
A solvent-reagent selection guide for Steglich-type esterification of carboxylic acids
Jordan, Andrew,Sneddon, Helen F.,Sydenham, Jack,Whymark, Kyran D.
supporting information, p. 6405 - 6413 (2021/09/10)
The Steglich esterification is a widely employed method for the formation of esters under mild conditions. A number of issues regarding the sustainability of this transformation have been identified, chiefly the use of hazardous carbodiimide coupling reagents in conjunction with solvents with considerable issues such as dichloromethane (DCM) and N,N-dimethylformamide (DMF). To overcome these issues, we have developed a solvent-reagent selection guide for the formation of esters via Steglich-type reactions with the aim of providing safer, more sustainable conditions. Optimum reaction conditions have been identified after high-throughput screening of solvent-reagent combinations, namely the use of Mukaiyama's reagent (Muk) in conjunction with solvent dimethyl carbonate (DMC). The new reaction conditions were also exemplified through the synthesis of a small selection of building-block like molecules and includes the formation of t-butyl esters.
Design, modification of phyllanthone derivatives as anti-diabetic and cytotoxic agents
Nguyen, Ngoc-Hong,Vo, Van-Giau,Phan, Hoang-Vinh-Truong,Ngo, Thanh-The,Sichaem, Jirapast,Nguyen, Thi-Phuong,Nguyen, Huu-Hung,Pham, Duc-Dung,Nguyen, Tien-Cong,Nguyen, Van-Kieu,Duong, Thuc-Huy
supporting information, p. 371 - 378 (2020/07/13)
Twelve benzylidene derivatives, one Baeyer-Villiger oxidative, six imine derivatives were successfully designed and synthesised from phyllanthone. In the search for potential new anti-diabetic agents, phyllanthone along with its benzylidene and oxidation analogues were evaluated for enzyme inhibition against α-glucosidase. In the benzylidene series, most analogues displayed stronger activity than the mother compound. Compound 1c revealed the strongest activity, outperforming the acarbose positive control with an IC50 value of 19.59 μM. Phyllanthone and its derivatives were then tested for cytotoxic activity against the K562 cell line. The imine analogues displayed the most powerful cytotoxic activity with 3cand 3d having IC50 values of 57.55 and 68.02 μM, respectively.
