- Synthesis, analysis and rearrangement of novel unnatural glucosinolates
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As part of a structure activity study to examine the interaction of glucosinolates with leaf surfaces, a number of glucosinolates were synthesised bearing novel side chain functionalities. These included 7-carboxyheptyl, heptyl, and naphthyl side chains. For the carboxyheptyl glucosinolate, a novel intramolecular rearrangement reaction was observed during the final deprotection step, which generated an ester attached to the C-3 of glucose. Studies by 1H NMR spectroscopy showed that the hydrophobic side chain associated with one face of the glucose ring and it was proposed that this was the driving force for the rearrangement. Similar hydrophobic interactions were also observed between the heptyl and naphthyl side chains and the glucose.
- Davidson, Nicola E.,Rutherford, Trevor J.,Botting, Nigel P.
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Read Online
- Photoassisted Cross-Coupling Reaction of α-Chlorocarbonyl Compounds with Arylboronic Acids
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A Suzuki-Miyaura cross-coupling reaction of α-chloroacetates or α-chloroacetamides with arylboronic acids is made possible by visible-light irradiation. This reaction provides a useful method for the synthesis of α-arylacetates and α-arylacetamides from chlorides under mild reaction conditions. An indole-3-acetic acid derivative that is the key intermediate of the plant hormone auxin can be synthesized from 1-Boc-indole in two steps by combining an iridium-catalyzed C-H borylation and a palladium-catalyzed cross-coupling reaction.
- Miura, Tomoya,Murakami, Masahiro,Oku, Naoki
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supporting information
p. 1616 - 1619
(2022/03/14)
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- Enantioselective Desymmetrization of 2-Aryl-1,3-propanediols by Direct O-Alkylation with a Rationally Designed Chiral Hemiboronic Acid Catalyst That Mitigates Substrate Conformational Poisoning
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Enantioselective desymmetrization by direct monofunctionalization of prochiral diols is a powerful strategy to prepare valuable synthetic intermediates in high optical purity. Boron acids can activate diols toward nucleophilic additions; however, the design of stable chiral catalysts remains a challenge and highlights the need to identify new chemotypes for this purpose. Herein, the discovery and optimization of a bench-stable chiral 9-hydroxy-9,10-boroxarophenanthrene catalyst is described and applied in the highly enantioselective desymmetrization of 2-aryl-1,3-diols using benzylic electrophiles under operationally simple, ambient conditions. Nucleophilic activation and discrimination of the enantiotopic hydroxy groups on the diol substrate occurs via a defined chairlike six-membered anionic complex with the hemiboronic heterocycle. The optimal binaphthyl-based catalyst 1g features a large aryloxytrityl group to effectively shield one of the two prochiral hydroxy groups on the diol complex, whereas a strategically placed "methyl blocker"on the boroxarophenanthrene unit mitigates the deleterious effect of a competing conformation of the complexed diol that compromised the overall efficiency of the desymmetrization process. This methodology affords monoalkylated products in enantiomeric ratios equal or over 95:5 for a wide range of 1,3-propanediols with various 2-aryl/heteroaryl groups.
- Estrada, Carl D.,Ang, Hwee Ting,Vetter, Kim-Marie,Ponich, Ashley A.,Hall, Dennis G.
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supporting information
(2021/04/07)
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- Coupling of Reformatsky Reagents with Aryl Chlorides Enabled by Ylide-Functionalized Phosphine Ligands
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The coupling of aryl chlorides with Reformatsky reagents is a desirable strategy for the construction of α-aryl esters but has so far been substantially limited in the substrate scope due to many challenges posed by various possible side reactions. This limitation has now been overcome by the tailoring of ylide-functionalized phosphines to fit the requirements of Negishi couplings. Record-setting activities were achieved in palladium-catalyzed arylations of organozinc reagents with aryl electrophiles using a cyclohexyl-YPhos ligand bearing an ortho-tolyl-substituent in the backbone. This highly electron-rich, bulky ligand enables the use of aryl chlorides in room temperature couplings of Reformatsky reagents. The reaction scope covers diversely functionalized arylacetic and arylpropionic acid derivatives. Aryl bromides and chlorides can be converted selectively over triflate electrophiles, which permits consecutive coupling strategies.
- Hu, Zhiyong,Wei, Xiao-Jing,Handelmann, Jens,Seitz, Ann-Katrin,Rodstein, Ilja,Gessner, Viktoria H.,Goo?en, Lukas J.
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supporting information
p. 6778 - 6783
(2021/02/01)
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- Synthesis and pharmacological screening: Sulfa derivatives of 2-pipecoline-bearing 1,3,4-oxadiazole core
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An electrophile, 1-(4-(bromomethylbenzenesulfonyl)-2-methylpiperidine, was synthesized by the reaction of 2-methylpiperidine (2-pipecoline) and 4-bromomethylbenzenesulfonyl chloride in a weak basic medium under pH control. A series of nucleophiles, 5-aryl/aralkyl-1,3,4-oxadiazol-2-thiols, were synthesized from corresponding carboxylic acids in three steps. The title molecules were synthesized by coupling the electrophile to nucleophiles in an aprotic medium using LiH as an activator. The structures of all synthesized compounds were corroborated through IR, 1H NMR, and EI-MS techniques. All the compounds were screened for their pharmacological behavior, particularly, antibacterial and enzyme inhibitory activities. Notably efficient results were obtained against both gram-positive and gram-negative bacterial strains. Regarding enzyme inhibition, compounds were efficient against acetylcholinesterase and butyrylcholinesterase.
- Aziz-ur-Rehman,Arif,Abbasi,Siddiqui,Rasool,Shah
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p. 328 - 339
(2017/07/04)
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- One-pot borylation/Suzuki-Miyaura sp2-sp3 cross-coupling
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We describe the first one-pot borylation/Suzuki-Miyaura sp2-sp3 cross-coupling between readily available aryl (pseudo)halides and activated alkyl chlorides. This method streamlines the synthesis of diaryl methanes, α-aryl carbonyls and allyl aryl compounds, substructures that are commonly found in life changing drug molecules.
- Whitaker, Luke,Harb, Hassan Y.,Pulis, Alexander P.
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p. 9364 - 9367
(2017/08/23)
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- Synthesis & characterization of 2-(substituted-phenyl)acetohydrazide analogs, 1,3,4-oxadiazoles, and 1,2,4-triazine Ring Systems: A novel class of potential analgesic and anti-inflammatory agents
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The new series of 2-(substituted-phenyl)acetohydrazides analogs, S-alkylated 5-substituted-1,3,4-oxadiazoles-2-thione derivatives and 5-arylidene-3-substituted-1,2,4-triazines have been synthesized in good yields and characterized by IR, NMR, mass spectral and elemental analyses. All the synthesized compounds 4(a-d), 5(a-d), 7(a-b), and 8(a-f) are evaluated for their in vitro DPPH scavenging, antimicrobial activity, in vivo analgesic, anti-inflammatory activities. The results of the anti-inflammatory activity are supported by molecular docking study with mouse COX-1 (PDB ID: 2CZT) and COX-2 (PDB ID: 3LN1) enzymes to predict their putative interactions. Among all the assays conducted, the compounds 5-(4-bromophenyl)-3-(naphthalen-2-ylmethyl)-1,2,4-triazine (4d) and2-{[5-(diphenylmethyl)-1,3,4-oxadiazol-2-yl]sulfanyl}-N-(pyrazin-2-yl)acetamide (8a) have emerged as the most potent molecules.
- Nayak, Prakash S.,Narayana, Badiadka,Fernandes, Jennifer,Sarojini, Balladka K.,Sheik, Sana,Shashidhara, Kenkere S.,Chandrashekhar, Konambi R.,Byrappa, Kullaiah
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p. 547 - 562
(2016/10/12)
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- Iron and manganese catalysts for the selective functionalization of arene C(sp2)-H bonds by carbene insertion
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The first examples of the direct functionalization of non-activated aryl sp2 C-H bonds with ethyl diazoacetate (N2CHCO2Et) catalyzed by Mn- or Fe-based complexes in a completely selective manner are reported, with no formation of the frequently observed cycloheptatriene derivatives through competing Buchner reaction. The best catalysts are FeII or MnII complexes bearing the tetradentate pytacn ligand (pytacn= 1-(2-pyridylmethyl)-4,7-dimethyl-1,4,7-triazacyclononane). When using alkylbenzenes, the alkylic C(sp3)-H bonds of the substituents remained unmodified, thus the reaction being also selective toward functionalization of sp2 C-H bonds. Exclusive catalysis: Iron- and-manganese-based catalysts selectively functionalize the C(sp2)-H bonds of benzene or alkylbenzenes through the formal insertion of the CHCO2Et group from N2CHCO2Et (see scheme). When using alkylbenzenes, the alkylic C(sp3)-H bonds of the substituents remain unmodified.
- Conde, Ana,Sabenya, Gerard,Rodríguez, Mònica,Postils, Verònica,Luis, Josep M.,Díaz-Requejo, M. Mar,Costas, Miquel,Pérez, Pedro J.
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supporting information
p. 6530 - 6534
(2016/06/01)
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- C-C Activation by Retro-Aldol Reaction of Two β-Hydroxy Carbonyl Compounds: Synergy with Pd-Catalyzed Cross-Coupling to Access Mono-α-arylated Ketones and Esters
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A retro-aldol reaction of two β-hydroxy compounds in synergy with Pd-catalyzed cross-coupling of aryl halides is reported herein, which produces selectively mono-α-arylated ketones and esters in good yields. This reaction is compatible with a broad range of aryl iodides, bromides, chlorides, and triflates and can tolerate an array of functional groups on the aromatic ring. Ready scale-up of this reaction to gram level is applicable without an appreciable decrease in the reaction yield. Furthermore, concise syntheses of biologically active isocoumarin and indole derivatives have been achieved to greatly demonstrate the synthetic value of this retro-aldol reaction. Finally, the reaction mechanism has been discussed on the basis of experimental observations and DFT computational results. A regulated six-membered-ring transition structure has been located for the key retro-aldol C-C cleavage, which constitutes the rate-determining step of a full catalytic cycle. The concept of C-C activation by retro-aldol reaction may also find applications in other fundamental reactions.
- Zhang, Song-Lin,Yu, Ze-Long
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- Novel hybrid-pyrrole derivatives: Their synthesis, antitubercular evaluation and docking studies
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Using novel hybrid molecules for the treatment of tuberculosis is one of the latest approaches. Keeping this concept in mind, thirty two hybrid compounds were synthesized, with pyrrole as one of the moieties, clubbed to coumarin, ibuprofen and isoniazid. The compounds were evaluated against Mycobacterium tuberculosis H37Rv strain. Compounds 7e and 8e exhibited MIC of 3.7 and 5.10 μg mL-1 and growth inhibition of 95% and 92%, respectively. These compounds were also active against single drug resistant bacterial strains. The compounds were devoid of cytotoxicity when tested against Vero African green monkey kidney cell line. Docking study was carried out on enoyl acyl carrier protein enzyme to provide some understanding into the mechanism of action of these compounds.
- Saha, Rikta,Alam, Md. Mumtaz,Akhter, Mymoona
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p. 12807 - 12820
(2015/02/19)
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- Condensed compound and organic light emitting diode comprising the same
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Provided are a condensed cyclic compound represented by chemical formula 1 and an organic electroluminescent device comprising the same. In the chemical formula 1, X, and R1 to R10 refer to the detailed description of the present invention. An organic light emitting device having an organic layer comprising the condensed cyclic compound has properties of low driving voltage, high light emitting efficiency and long lifespan.COPYRIGHT KIPO 2016
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Paragraph 0321; 0321; 0323
(2016/12/01)
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- Bis azide-triphenylphosphine as a reagent for esterification at room temperature
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Modified Staudinger reaction is a well-established reaction for the amide synthesis from organic azides and carboxylic acids in the presence of phosphorous reagents. In contrary to this, it is notable that bis azide in the presence of triethylphosphite or trimethylphosphite does not afford the expected bis amides but affords the ethyl or methyl esters of the carboxylic acids respectively. This serendipitous observation when further investigated results in the discovery of bis azide-triphenylphosphine as an efficient reagent for esterification at room temperature.
- Dinesh, Murugan,Archana, Sivasubramaniyan,Ranganathan, Raja,Sathishkumar, Murugan,Ponnuswamy, Alagusundaram
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supporting information
p. 6975 - 6979
(2015/11/27)
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- Catalytic Enantioselective Synthesis of Atropisomeric Biaryls: A Cation-Directed Nucleophilic Aromatic Substitution Reaction
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A catalytic enantioselective nucleophilic aromatic substitution reaction which yields axially chiral biaryl derivatives in excellent yields with e.r. values of up to 97:3 has been developed. This process uses a chiral counterion to direct the addition of thiophenolate to a prochiral dichloropyrimidine by a tandem desymmetrization/kinetic resolution mechanism. The products can be derivatized to a range of atropisomeric structures without any reduction in enantioenrichment, thus offering access to unexplored chiral biaryl architectures.
- Armstrong, Roly J.,Smith, Martin D.
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supporting information
p. 12822 - 12826
(2016/02/18)
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- Synthesis of α-aryl esters and nitriles: Deaminative coupling of α-aminoesters and α-aminoacetonitriles with arylboronic acids
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Transition-metal-free synthesis of α-aryl esters and nitriles using arylboronic acids with α-aminoesters and α-aminoacetonitriles, respectively, as the starting materials has been developed. The reaction represents a rare case of converting C(sp3)-N bonds into C(sp3)-C(sp2) bonds. The reaction conditions are mild, demonstrate good functional-group tolerance, and can be scaled up. Touch base: A transition-metal-free protocol for the synthesis of α-aryl esters and nitriles by deaminative coupling is presented. Strong bases and transition-metal catalysts are not needed. The new synthetic method uses readily available starting materials and demonstrates wide substrate scope.
- Wu, Guojiao,Deng, Yifan,Wu, Chaoqiang,Zhang, Yan,Wang, Jianbo
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supporting information
p. 10510 - 10514
(2016/02/18)
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- Lewis acid promoted dual bond formation: Facile synthesis of dihydrocoumarins and spiro-tetracyclic dihydrocoumarins
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Lewis acid (FeCl3) mediated dual bond (C-C and C-O) formation for synthesis of 3,4-dihydrocoumarins is presented. This method has successfully delivered a number of dihydrocoumarins containing dense functionalities on the aromatic ring. Significantly, the present method enabled achieving dihydrocoumarins with tertiary as well as quaternary carbon atoms at the benzylic position. Gratifyingly, the novel spiro-tetracyclic lactones have also been dextrously prepared using this process. the Partner Organisations 2014.
- Niharika, Pedireddi,Ramulu, Bokka Venkat,Satyanarayana, Gedu
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p. 4347 - 4360
(2014/06/23)
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- Substituted naphthalen-1-yl-acetic acid hydrazides: Synthesis, antimicrobial evaluation and QSAR analysis
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A series of naphthalen-1-yl-acetic acid benzylidene/(1-phenyl-ethylidene)- hydrazides (1-36) was synthesized and tested, in vitro, for antiviral, antibacterial and antifungal activities. The antibacterial and antifungal screening results indicated that compounds having o-bromo, methoxy and hydroxy substitutents were the most active ones. The results of antiviral evaluation showed that none of the synthesized derivatives inhibited the viral infection at subtoxic concentrations. QSAR investigations revealed that the multi-target QSAR model was more effective in describing the antimicrobial activity than the one-target QSAR models. Further, it revealed the importance of the partition coefficient (log P) followed by energies of the highest occupied molecular orbital (HOMO) and topological parameters, molecular connectivity indices ( 1X, 3X and 3Xv) in describing the antimicrobial activity of substituted hydrazides.
- Narang, Rakesh,Narasimhan, Balasubramanian,Sharma, Sunil,De Clercq, Erik,Pannecouque, Christophe,Balzarini, Jan
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p. 249 - 274
(2013/07/28)
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- Synthesis of arylacetates from benzylic alcohols and oxalate esters through decarboxylative coupling
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Follow that dream: By combining a reversible transesterification between benzylic alcohols and dialkyl oxalates with catalytic decarboxylation of the resulting esters, a regiospecific C-C-bond-forming reaction to give α-arylacetates was achieved. In the overall process, CO2 and a volatile alcohol are the only byproducts. Various α-arylacetates were thus synthesized in high yields from easily accessible starting materials in the presence of catalytic amounts of Pd(OAc)2, dppp, and DABCO (see scheme). Copyright
- Gruenberg, Matthias F.,Goossen, Lukas J.
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supporting information
p. 7334 - 7337
(2013/06/27)
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- PROCESS FOR SYNTHESIZING PHENYLACETIC ACID BY CARBONYLATION OF TOLUENE
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A production process for substituted phenylacetic acids or ester analogues thereof is disclosed. In this process toluene or toluene substituted with various substituents, an alcohol, an oxidant and carbon monoxide are used as raw materials to obtain compounds comprising structure of phenylacetic acid ester or analogues thereof by catalysis of the complex catalyst formed from transition metal and ligand, and such compounds are hydrolyzed to obtain various substituted phenylacetic acid based compounds. This type of compounds and their derivatives serve as important fine chemicals used widely in the industries of pharmaceuticals, pesticides, perfume and the like.
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Paragraph 0072; 0073
(2013/11/19)
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- Pharmacological screening for anti-inflammatory, analgesic activity of pyrazolyl derivatives along with molecular docking studies
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The pyrazole derivatives were synthesized and pharmacologically evaluated for analgesic (tail flick) and anti-inflammatory (based on carrageenan-induced paw edema) activities. Compound 4k showed high potency as an anti-inflammatory agent after 3 and 4-h time intervals (P0.001) equipotent to indomethacin. They were devoid of ulcerogenic potential when administered at a dose of 30 mg/kg. The compounds, which showed less ulcerogenic action, also showed reduced malondialdehyde content (MDA), which is one of the byproduct of lipid peroxidation. Further docking studies of titled compounds was done to understand key interactions responsible for observed inhibition of COX enzyme. The most active compound 4k was found to have -11.192 kcal/mol, as the free energy of binding. Various other key interactions between the synthesized molecules and active site of COX-2 enzyme, responsible for the obtained pharmacological results were also reported. Most of the active compounds were docked well into the active sites of the receptor. Springer Science+Business Media, LLC 2011.
- Kaushik, Darpan,Kumar, Rajnish,Khan, Suroor Ahmed,Chawla, Gita
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p. 3646 - 3655
(2013/02/23)
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- Palladium-catalyzed oxidative carbonylation of benzylic C-H bonds via nondirected C(sp3)-H activation
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A new strategy for generating benzylpalladium reactive species from toluenes via nondirected C(sp3)-H activation has been developed. This led to construction of an efficient Pd-catalyzed reaction protocol for the oxidative carboxylation of benzylic C-H bonds to form substituted 2-phenylacetic acid esters and derivatives from inexpensive, commercially available starting materials.
- Xie, Pan,Xie, Yinjun,Qian, Bo,Zhou, Han,Xia, Chungu,Huang, Hanmin
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supporting information; experimental part
p. 9902 - 9905
(2012/08/08)
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- Pd-catalyzed decarboxylative cross-couplings of potassium malonate monoesters with aryl halides
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An efficient catalytic protocol for Pd-catalyzed decarboxylative cross-coupling of potassium malonate monoesters and derivatives with aryl bromides and chlorides are described. Because of its broad applicability, this new catalytic system provides an alternative method for the preparation of diverse aryl acetic acids and derivatives.
- Feng, Yi-Si,Wu, Wei,Xu, Zhong-Qiu,Li, Yan,Li, Ming,Xu, Hua-Jian
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experimental part
p. 2113 - 2120
(2012/03/26)
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- Doubly activated supramolecular reaction: Transesterification of acyclic oligoether esters with metal alkoxides
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Transesterification reactions of acyclic oligoether esters E3-E10 with metal alkoxides were accelerated upon noncovalent complexation of the esters with metal ions. In the reaction of monovalent alkaline metal alkoxides, CH3ONa and CH3OK, plots of the observed rate constants kobs with respect to the chain length of E3-E10 showed selective acceleration of the transesterification. Compared with the shortest E3, which can hardly bind metal ion, 4.3- and 6.6-fold accelerations in the maxima were achieved in the combinations of E5/CH3ONa and E6/CH3OK, respectively. Supramolecular intermediate complex could be spectrometrically visualized by ESI-FT-ICR-MS in the course of reaction. Kinetic experiments, together with structural analyses by means of NMR, mass spectrometry, and DFT calculations of the intermediate complexes, indicate that a size-fit complex of host substitute with alkali metal ion allows strong electron withdrawing due to the close contact of the carbonyl oxygen to the metal ion, resulting in the selective rate enhancement of the reaction, while in the reaction of E3-E10 with a divalent alkaline earth metal alkoxide, (CH3- CH2O)2Ba, the kobs values increased stepwise with elongation of the side arm to attain an dramatic large acceleration. In comparison with the kobs of E3, 4610-fold acceleration was achieved in the reaction of E10. The double activation of the host substrate and guest counter nucleophile at once brings about this extraordinary rate acceleration. The strong wrapping complexation of long oligoether ester with barium ethoxide allows for the effective electron withdrawal from the ester carbonyl group (host activation) as well as separation of the accompanying guest alkoxide anions (guest activation).
- Kawakami, Kazumitsu,Sei, Yoshihisa,Yamaguchi, Kentaro,Tsuda, Akihiko
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supporting information; scheme or table
p. 875 - 881
(2011/04/18)
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- Process for Preparing Aryl- and Heteroarylacetic Acid Derivatives
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The present invention relates to a novel process for preparing α-arylmethylcarbonyl compound of the formula (III), characterized in that aryl- and heteroarylacetic acids and derivatives thereof of the formula (I) are reacted with α-halomethylcarbonyl compounds of the formula (II) in the presence of a palladium catalyst, of a phosphine ligand, of an inorganic base and of a phase transfer catalyst, optionally using an organic solvent.
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Page/Page column 5-6
(2011/08/06)
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- Reactions of CF3-substituted boranes with α-diazocarbonyl compounds
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Boranes substituted with a CF3-group can be generated from methyl boronic esters RB(OMe)2 and Me3SiCF3/KF followed by treatment with Me3SiCl. These boranes are stable only in coordinating solvents, and due to the increased Lewis acidity of boron, react rapidly with α-diazocarbonyl compounds to give the products of transfer of the organic group from boron. Alkyl, aryl, vinyl, and alkynyl boronic esters can be used in this reaction.
- Elkin, Pavel K.,Levin, Vitalij V.,Dilman, Alexander D.,Struchkova, Marina I.,Belyakov, Pavel A.,Arkhipov, Dmitry E.,Korlyukov, Alexander A.,Tartakovsky, Vladimir A.
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p. 5259 - 5263
(2011/10/31)
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- Palladium-catalyzed cross-coupling of sterically demanding boronic acids with α-bromocarbonyl compounds
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A catalyst system generated in situ from Pd(dba)2 and tri(o-tolyl)phosphine mediates the coupling of arylboronic acids with alkyl α-bromoacetates under formation of arylacetic acid esters at unprecedented low loadings. The new protocol, which involves potassium fluoride as the base and catalytic amounts of benzyltriethylammonium bromideas a phase transfer catalyst, is uniquely effective for the synthesis of sterically demanding arylacetic acid derivatives. (Figure presented)
- Zimmermann, Bettina,Dzik, Wojciech I.,Himmler, Thomas,Goossen, Lukas J.
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experimental part
p. 8107 - 8112
(2011/11/07)
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- Acylation of Meldrum's acid with arylacetic acid imidazolides as a convenient method for the synthesis of 4-aryl-3-oxobutanoates
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C-Acylation of Meldrum's acid by (het)arylacetic acids in ethanol in the presence of 1,1′-carbonyldiimidazole leads to ethyl 4-(het)aryl-3- oxobutanoates in high yields.
- Shimkin,Shirinian,Mailian,Lonshakov,Gorokhov,Krayushkin
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experimental part
p. 139 - 142
(2011/09/12)
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- Gold-catalyzed naphthalene functionalization
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The complexes IPrMCl (IPr = 1,3-bis(diisopropylphenyl)imidazol-2-ylidene, M = Cu, 1a; M = Au, 1b), in the presence of one equiv of NaBAr'4 (Ar' = 3,5-bis(trifluoromethyl)phenyl), catalyze the transfer of carbene groups: C(R)CO2Et (R = H, Me) from N2C(R)CO2Et to afford products that depend on the nature of the metal center. The copper-based catalyst yields exclusively a cycloheptatriene derivative from the Buchner reaction, whereas the gold analog affords a mixture of products derived either from the formal insertion of the carbene unit into the aromatic C-H bond or from its addition to a double bond. In addition, no byproducts derived from carbene coupling were observed.
- Perez, Pedro J.,Diaz-Requejo, M. Mar,Rivilla, Ivan
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experimental part
p. 653 - 657
(2011/08/03)
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- N'-[(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)methylene] 2/4-substituted hydrazides: Synthesis and anticonvulsant activity
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A series of N'-[(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)methylene] 2/4-substituted hydrazides were synthesized using appropriate synthetic route and characterized by elemental analysis and spectral data. The anticonvulsant activity of some of the synthesized compounds were evaluated against maximal electroshock induced seizure (MES) and subcutaneous pentylenetetrazol (scPTZ) induced seizure models in mice. The neurotoxicity were assessed using the rotorod method. All the test compounds were administered at doses of 30, 100, and 300 mg/kg body weight and the anticonvulsant activity was noted at 0.5 and 4 h time intervals after the drug administration. Among the compound tested, all except 5g showed protection from seizures in both the animal models. Some titled compounds exhibited lesser CNS depression and neurotoxicity compared to phenytoin. A series of substituted hydrazide derivatives were synthesized, evaluated for their anticonvulsant potency in two animal models along with behavioural and neurotoxicity screen and also subjected to computational parameters.
- Kaushik, Darpan,Khan, Suroor Ahmad,Chawla, Gita,Kumar, Suresh
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experimental part
p. 3943 - 3949
(2010/09/11)
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- Design & synthesis of 2-(substituted aryloxy)-5-(substituted benzylidene)-3-phenyl-2,5-dihydro-1H-[1,2,4] triazin-6-one as potential anticonvulsant agents
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A series of 2-(substituted aryloxy)-5-(substituted benzylidene)-3-phenyl-2, 5-dihydro-1H-[1,2,4] triazin-6-one were designed & synthesized using appropriate synthetic route keeping in view the structural requirement of pharmacophore and evaluated for anticonvulsant activity and CNS activities. After intraperitoneal injection to mice, some synthesized derivatives were examined in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol (scPTZ) induced seizure and neurotoxicity screens. Those found potent were also evaluated for behavioural impairment and depression activity. Among the compound tested, 5 eIX showed protection from seizures in both the animal models at dose level of 30 mg/kg while 5 bII & 5 cII showed protection against scPTZ model at same dose level. Some titled compounds exhibited lesser CNS depression and neurotoxicity compared to clinically effective drug. A series of substituted [1,2,4] triazin-6-one derivatives were synthesized, evaluated for their anticonvulsant potency on two animal models along with CNS activity and neurotoxicity and also subjected to computational parameter.
- Kaushik, Darpan,Khan, Suroor Ahmad,Chawla, Gita
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experimental part
p. 3960 - 3969
(2010/09/11)
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- Water works: An efficient palladium-catalyzed cross-coupling reaction between boronic acids and bromoacetate with aminophosphine ligand
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Water greatly restrained the formation of self-coupling of boronic acids in a palladium-catalyzed cross-coupling reaction between boronic acids and ethyl bromoacetate with an aminophosphine ligand; good to excellent yields of cross-coupling product were obtained.
- Peng, Zhi-Yong,Wang, Jian-Ping,Cheng, Jiang,Xie, Xiao-Min,Zhang, Zhaoguo
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experimental part
p. 8238 - 8241
(2010/10/21)
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- Synthesis of 4H-cyclopenta[def]phenanthrene from 1-naphthylacetic acid
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4H-cyclopenta[def ]phenanthrene (CPP) was prepared from 1-naphthylacetic acid in six steps with an overall yield of 36%. From easily available ethyl 1-naphthaleneacetate, the Michael addition and Lewis acid catalyzed dicyclization provided the diketone, which was reduced and dehydrated to give CPP. Copyright
- Kim, Jinwoo,Jin, Youngeup,Song, Suhee,Kim, Il,Suh, Hongsuk
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supporting information; experimental part
p. 1008 - 1008
(2012/10/08)
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- Enzymatic desymmetrization of prochiral 2-substituted-1,3-diamines: Preparation of valuable nitrogenated compounds
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A wide range of prochiral 1, 3-diamines were first efficiently synthesized and subsequently desymmetrized by using lipase from Pseudomonas cepacia as catalyst and diallyl carbonate as alkoxycarbonylating agent. In all cases, the amino carbamates of R-configuration were recovered. Final selective cleavage of the N-allyloxycarbonyl moiety was carried out under mild reaction conditions, which demonstrates the high versatility and potential of this chemoenzymatic route as a source of intermediates in the synthesis of related optically active nitrogenated derivatives.
- Rios-Lombardia, Nicolas,Busto, Eduardo,Garcia-Urdiales, Eduardo,Gotor-Fernandez, Vicente,Gotor, Vicente
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supporting information; experimental part
p. 2571 - 2574
(2009/07/25)
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- Fe2(SO4)3·4H 2O/concentrated H2SO4: An efficient catalyst for esterification
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The mixed catalyst system, Fe2(SO4) 3·4H2O/concentrated H2SO4 has been applied to catalyse effectively the esterification of α,β-unsaturated acids, aliphatic acids and heterocyclic aromatic acids with ethanol and methanol.
- Liang, Yong-Min,Xu, Qi-Hai,Wu, Xiao-Li,Ma, Yong-Xiang
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p. 226 - 227
(2007/10/03)
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- Palladium-catalysed arylation of acetoacetate esters to yield 2-arylacetic acid esters
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The coupling reaction between ethyl acetoacetate and a number of aryl halides in the presence of palladium acetate, a bulky and electron rich phosphine and K3PO4 is described. The arylated acetoacetate ester is de-acylated under the reaction conditions resulting in the generation of 2-arylacetic acid esters, constituting a mild alternative to direct arylation of carboxylate esters.
- Zeevaart, Jacob G.,Parkinson, Christopher J.,De Koning, Charles B.
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p. 4261 - 4264
(2007/10/03)
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- 1,2-disubstituted-6-oxo-3-phenyl-piperidine-3-carboxamides and combinatorial libraries thereof
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The invention relates to combinatorial libraries containing two or more novel piperidine-3-carboxamide derivative compounds, methods of preparing the piperidine-3-carboxamide derivative compounds and piperidine-3-carboxamide derivative compounds bound to a resin
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- Remarkable co-catalysis by copper(I) oxide in the palladium catalyzed cross-coupling of arylboronic acids with ethyl bromoacetate
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Copper(I) oxide can effectively co-catalyze the Suzuki type cross-coupling reactions of arylboronic acids with ethyl bromoacetate. As an alternative protocol for introducing the methylenecarboxy group into functionalized molecules, this reaction occurs in
- Liu, Xing-Xin,Deng, Min-Zhi
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p. 622 - 623
(2007/10/03)
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- Pd-catalyzed synthesis of arylacetic acid derivatives from boronic acids
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A palladium(0)-catalyzed cross-coupling reaction between arylboronic acids or esters and α-bromoacetic acid derivatives is described which allows the synthesis of various functionalized arylacetic acid derivatives under mild conditions.
- Goossen
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p. 669 - 670
(2007/10/03)
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- Synthesis of substituted chrysenes and phenanthrenes
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3-Methylchrysene (9a), 2, 3, 9-trimethylchrysene (9b), 2, 6-dimethylphenanthrene (16a) and 1-isopropyl-4,6-dimethylphenanthrene (16b) have been synthesised in the following steps. β-(1-Naphthyl)ethyl bromide (6a), β-(6,7-dimethyl-1-naphthyl)ethyl bromide (6b), β-(3-methylphenyl)ethyl bromide (13a) and β-(2-isopropyl-5-methylphenyl)ethyl bromide (13b) are separately condensed with potassium salt of 1-carbethoxy-4-methylcyclohexane-2-one (1) to give respectively 7a, 7b, 14a and 14b. PPA cyclisation of 7a and 7b affords 8a and 8b while 14a affords 15a and 14b gives a mixture of 15b and 15c. Aromatisation of 8a and 8b leads to 9a and 9b and that of 15a gives 16a while 15b and 15c both produce 16b. The structures assigned are consistent with their spectral data.
- Mitra, Ashutosh,Ghoshe, Swati
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p. 785 - 789
(2007/10/03)
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- A Convenient Synthesis of New Macrocyclic Naphthalenophanes
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The (1,4)naphthalenophanes 6a, 6b, 7a, and 7b were synthesized regiospecifically in two steps from the appropriate α,ω-di-1-naphthylalkanes by a Friedel-Crafts acetylation of the two naphthalene groups followed by cyclization/dimerization of the resulting diketones by a McMurry reaction.The macrocyclic naphthalenophanes 6a and 6b exist in solution as a mixture of conformers while 7a and 7b were identified as the anti isomers. - Key Words: Cyclophanes / Naphthalenophanes / McMurry reaction
- Gruetzmacher, Hans-Friedrich,Nolte, Gerald
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p. 1157 - 1162
(2007/10/02)
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- Derivatives of 2-aminoalkyl-5-arylalkyl-1,3-dioxanes, their preparation and their therapeutic application
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A compound which is a 2-aminoalkyl-5-arylalkyl-1,3-dioxane of general formula (I) STR1 in which m represents 0 or 1; n represents 1, 2, 3 or 4; R1 represents hydrogen or methyl; R2 represents hydrogen, methyl or an alkanoyl group of the general formula COR' in which R' represents a hydrogen atom or a linear or branched C1 -C4 -alkyl group, or an alkoxycarbonyl group of the general formula COOR" in which R" represents a linear or branched C1 -C4 -alkyl group; and Ar represents either a phenyl group optionally carrying one or two substituents selected from halogen, C1 -C4 alkyl, methoxy and trifluoromethyl, or a naphthalen-1-yl or naphthalen-2-yl group optionally carrying a substituent selected from halogen, methyl, methoxy and cyclopropylmethoxy groups, in the form of a cis- or trans-stereoisomer, and in the form of a free base or an acid addition salt thereof and its therapeutic use.
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- Mild, one-pot conversion of carboxylic acids into esters using phase transfer catalysis
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One-pot conversion of carboxylic acids into esters under the influence of phase transfer catalysis is reported.The method is shown to work satisfactorily for optically active acids having epimerisable α-hydrogen.
- Puntambekar, Hemalata M,Naik, D G,Kapadi, A H
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p. 793 - 794
(2007/10/02)
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- Facile esterification of sulfonic acids and carboxylic acids with triethylorthoacetate
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Triethylorthoacetate was found to be surprisingly more effective than triethylorthoformate in the esterification of sulfonic acids and carboxylic acids. Using this reagent, esters of sulfonic and carboxylic acids are prepared in high yields.
- Trujillo, John I.,Gopalan, Aravamudan S.
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p. 7355 - 7358
(2007/10/02)
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- Low-valent titanium induced reductive coupling reaction of carboxylic derivatives with aromatic ketones
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The intermolecular and intramolecular coupling reaction of carboxylic derivaties with aromatic ketones induced by titanium tetrachloride and zinc powder was studied.
- Shi, Da-Qing,Chen, Jian-Xie,Chai, Wen-Ying,Chen, Wei-Xing,Kao, Tsi-Yu
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p. 2963 - 2964
(2007/10/02)
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- Ester Homologation Revisited: A Reliable, Higher Yielding and Better Understood Procedure
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Enolate anions 3 and 6, prepared via enolization of α-bromo and dibromo ketones 4 and 5 were converted in high yield to ynolate anions 10 by respective addition of lithium tetramethylpiperidide (to effect deprotonation, 3 --> 7) or butyllithium (to effect metal-halogen exchange, 6 --> 7).Mixtures of such enolates were also obtainable from esters 1 on a large-scale (25 mmol) via in situ formation and addition of lithiodibromomethane (from methylene bromide and lithium tetramethylpiperidide), followed by treatment of the resulting adducts with lithiumhexamethyldisilazide to ensure complete enolization.Addition of sec-butyllithium and n-butyllithium to effect ynolate anion formation, followed by quenching of the reaction mixtures into acidic ethanol, reproducibly afforded homologated esters 8 in 67-90percent yield.Demonstrated for ethyl esters 1 having the carbethoxy moiety attached to primary, secondary, tertiary, aryl, and alkenyl groups, this general procedure provides a convenient, large-scale alternative to the classical Arndt-Eistert sequence.
- Kowalski, Conrad J.,Reddy, Rajarathnam E.
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p. 7194 - 7208
(2007/10/02)
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- IODIDE ION PROMOTION BENZYL CHLORIDE-BORATE ESTER CARBONYLANION REACTIONS
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Esters are isolated in fine yields from the rhodium(I) catalyzed reaction of benzyl chlorides with borate esters and carbon monoxide, in the presence of potassium iodide.
- Alper, Howard,Hamel, Nathalie,Smith, David J. H.,Woell, James B.
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p. 2273 - 2274
(2007/10/02)
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- Cathodic Reduction of Ethyl α-Bromonaphthalene-1- and-2-acetate: Electrochemical Synthesis and Voltammetric Behaviour of meso- and DL-Diethyl 2,3-Di-1- and-2-naphthylsuccinate
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Diethyl 2,3-dinaphthylsuccinates (5)-(8) can be prepared through electrochemical reduction of ethyl α-bromonaphthalene-1- and -2-acetate (3) or (4) (ABr) in DMF-0.1 M Et4NClO4 at a vitreous carbon electrode.These dinaphthylsuccinates (5)-(8) (A-A) are good model systems for the study of electron transfer to molecules containing two identical redox centres.Cyclic voltammetry shows that dimeric species A-A are reduced at more positive potentials than the corresponding AH compound; meso-diethyl 2,3-di-2-naphthylsuccinate (7) is reduced at a slightly more positive potential than the corresponding DL-succinate (8).The 1-naphthyl derivatives are more easily reduced than the corresponding 2-naphthyl compounds, the difference being larger between bromoesters (3) and (4).
- De Luca, Carlo,Inesi, Achille,Rampazzo, Liliana
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p. 209 - 212
(2007/10/02)
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- Synthesis of Ethyl Arylacetates by Means of Friedel-Crafts Reaction of Aromatic Compounds with Ethyl α-Chloro-α-(methylthio)acetate
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Friedel-Crafts reaction of aromatic compounds with ethyl α-chloro-α-(methylthio)acetate (1) gave ethyl α-(methylthio)arylacetates (2), which were readily converted into ethyl arylacetates (3) by reductive desulfurization with Raney nickel or zinc dust-acetic acid.The reactions were applied to the syntheses of ibufenac (5) and alclofenac (6), which are anti-inflammatory agents.
- Tamura, Yasumitsu,Choi, Hong Dae,Shindo, Hirohisa,Ishibashi, Hiroyuki
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p. 915 - 921
(2007/10/02)
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- Introduction of α-(acyl) methylthiomethyl group into the aromatic ring by Friedel-Crafts reaction
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Friedel-Crafts α-(acyl)methylthiomethylations of aromatic compounds with α-ethoxycarbonyl, -acetyl, -benzoyl, and -cyano-α-(methylthio)methyl chlorides are described. The resulted products are easily converted to acylmethylated aromatics such as phenylacetate and phenylacetone by reductive desulfurization.
- Tamura,Shindo,Uenishi,Ishibashi
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p. 2547 - 2548
(2007/10/02)
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