448959-84-0Relevant academic research and scientific papers
Green synthesis of graphene oxide (GO)-anchored Pd/Cu bimetallic nanoparticles using: Ocimum sanctum as bio-reductant: An efficient heterogeneous catalyst for the Sonogashira cross-coupling reaction
Borah, Geetika,Gogoi, Pradip K.,Hussain, Farhaz Liaquat,Mech, Swapna Devi,Pahari, Pallab,Sultana, Samim
, p. 23108 - 23120 (2020/07/03)
To explore the synergism between two metal centers we have synthesized graphene oxide (GO) supported Pd/Cu?GO, Pd?GO and Cu?GO nanoparticles through bio-reduction of Pd(NO3)2 and CuSO4·5H2O using Tulsi (Ocimum sanctum) leaf extract as the reducing and stabilizing agent. The graphene oxide (GO) was obtained by oxidation of graphite following a simplified Hummer's method. The as-prepared nanomaterials have been extensively characterized by FTIR, powder X-ray diffraction (PXRD), HRTEM, TEM-EDS, XPS, ICP-AES and BET surface area measurement techniques. The morphological study of Pd/Cu?GO revealed that crystalline bimetallic alloy type particles were dispersed on the GO layer. The activity of Pd?GO, Cu?GO and Pd/Cu?GO as catalysts for the Sonogashira cross-coupling reaction have been investigated and it was found that the Pd/Cu?GO nanostructure showed highly superior catalytic activity over its monometallic counterparts, substantiating the cooperative influence of the two metals. The inter-atom Pd/Cu transmetalation between surfaces was thought to be responsible for its synergistic activity. The catalyst showed higher selectivity towards coupling of aryl iodides with both aliphatic and aryl alkynes resulting in moderate to excellent isolated yield of the desired products (45-99%). The products have been characterized by GC-MS and 1H-NMR spectroscopic techniques and compared with authentic samples. The Pd/Cu?GO catalyst could be easily isolated from the reaction products and reused for up to at least ten successive runs effectively.
Synthesis of N-Substituted Iminosugar Derivatives and Evaluation of Their Immunosuppressive Activities
Lv, Zhuo,Song, Chengcheng,Niu, Youhong,Li, Qin,Ye, Xin-Shan
supporting information, p. 338 - 351 (2018/02/27)
It is important to find more effective and safer immunosuppressants, because clinically used immunosuppressive agents have significant side effects. A series of N-substituted iminosugar derivatives were designed and synthesized, and their immunosuppressive effects were evaluated by the CCK-8 assay. The results revealed that iminosugars 10 e and 10 i, that is, (3R,4S)-1-(4-heptyloxylphenylethyl)pyrrolidine-3,4-diol and (3R,4S)-1-[2-(2-chloro-4-(p-tolylthio)-phenyl-1-yl)ethyl]pyrrolidine-3,4-diol, respectively, exhibited the strongest inhibitory effects on mouse splenocyte proliferation (IC50=2.16 and 2.48 μm, respectively), whereas the iminosugars containing an amide group near the hydrophilic head (compounds 10 j–n) exhibited no inhibitory effects. Further studies revealed that the inhibitory effects on splenocyte proliferation may have come from the suppression of both IFN-γ and IL-4 cytokines. Our results suggest that synthetic iminosugars, especially compounds 10 e and 10 i, hold potential as immunosuppressive agents.
Highly Regio and Stereoselective Intermolecular Seleno- and Thioamination of Alkynes
Zheng, Guangfan,Zhao, Jinbo,Li, Zhanyu,Zhang, Qiao,Sun, Jiaqiong,Sun, Haizhu,Zhang, Qian
supporting information, p. 3513 - 3518 (2016/03/05)
By using N-fluorobenzenesulfonimide as both the oxidant and the amination reagent, we have realized the first example of the intermolecular chalcogenative amination of alkynes, which grants facile, highly regio- and stereoselective access to chalcogenated enamides. The reaction features mild conditions, high yields and selectivities, remarkably broad substrate scope, and excellent functional group tolerance. Mechanistic studies indicate the in situ generated chalcogen imidates to be the actual reactive species, which in turn, has clarified the mechanism of related transformations. These reactions represent significant additions to the development of the highly selective amino bisfunctionalization of alkynes.
Palladium and copper catalyzed Sonogashira decarboxylative coupling of aryl iodides and alkynyl carboxylic acids
Maaliki, Carine,Chevalier, Yoan,Thiery, Emilie,Thibonnet, Jér?me
supporting information, p. 3358 - 3362 (2016/07/11)
A mild procedure of palladium and copper catalyzed decarboxylative cross-coupling reaction of aryl halides and alkynyl carboxylic acids has been developed. Low molecular weight acids, to introduce small building blocks, were specifically used. This method
A dithizone-functionalized polystyrene resin-supported Pd(II) complex as an effective catalyst for Suzuki, Heck, and copper-free Sonogashira reactions under aerobic conditions in water
Bakherad, Mohammad,Jajarmi, Saeideh
, p. 152 - 159 (2013/04/24)
A novel polystyrene-supported palladium(II) dithizone complex is found to be a highly active catalyst for the Suzuki, Heck, and Sonogashira reactions of aryl halides in water. By this protocol, aryl halides, coupled with phenyl boronic acid (Suzuki reaction), alkenes (Heck reaction) or terminal alkyne (Sonogashira reaction), smoothly affords the corresponding cross-coupling products in good to excellent yields. Furthermore, the catalyst shows good thermal stability and recyclability. The catalyst was recycled for the Suzuki, Heck, and Sonogashira reactions for five runs without appreciable loss of its catalytic activity and negligible metal leaching.
Sonogashira/hydroarylation sequential reactions: Catalyzed by NHC-Pd complexes
Yang, Longguang,Li, Yunfei,Chen, Qian,Du, Yufeng,Cao, Changsheng,Shi, Yanhui,Pang, Guangsheng
, p. 5178 - 5184 (2013/06/27)
It was found that an air-stable NHC-palladium complex of Pd[(s)-3-C 3H5-4-(C5H5CH2)-1-(2,6- iPr2C6H3)-C3H 3N2](C5H5N)Br2 derived from l-phenylalanine is an effective pre-catalyst for copper-free and phosphine-free Sonogashira reaction of alkynes under aerobic conditions in short reaction time. Moreover, the palladium compound would be reused to catalyze the hydroarylation of alkyne prepared from Sonogashira reaction, which makes firstly Sonogashira/Hydroarylation sequential reactions successful. The arylation of alkynes underwent with a high regio- and stereoselectivity and only trans-arylation of alkyne was observed. No Z/E isomerization of the olefin was observed in the system.
Synthesis and characterization of novel chiral NHC-palladium complexes and their application in copper-free Sonogashira reactions
Yang, Longguang,Guan, Pei,He, Pan,Chen, Qian,Cao, Changsheng,Peng, Yu,Shi, Zhan,Pang, Guangsheng,Shi, Yanhui
experimental part, p. 5020 - 5025 (2012/06/04)
A new series of chiral N-heterocyclic carbene (NHC) palladium complexes were synthesized from a relatively inexpensive amino acid, l-phenylalanine. All these compounds were fully characterized by 1H-NMR, 13C-NMR and elemental analysis. The X-ray molecular structures of two of the complexes were reported. The catalytic activity of the four palladium complexes was successfully tested in the Sonogashira reaction under copper free conditions in air. The palladium complex 3a provided good activity in the Sonogashira coupling reaction. The Royal Society of Chemistry 2012.
Pd-EnCat TPP30 as a catalyst for the generation of highly functionalized aryl- and alkenyl-substituted acetylenes via microwave-assisted sonogashira type reactions
Sedelmeier, Joerg,Ley, Steven V.,Lange, Heiko,Baxendale, Ian R.
supporting information; experimental part, p. 4412 - 4420 (2010/01/07)
We report a rapid microwave-assisted Sonogashira crosscoupling of aryl iodides and bromides with terminal alkynes using Pd-EnCat TPP30. Both electron-rich and electrondeficient aryl halides reacted smoothly with a broad variety of terminal alkynes in MeCN
N-Phenyl-N′-(2-chloroethyl)ureas (CEU) as potential antineoplastic agents. Part 2: Role of ω-hydroxyl group in the covalent binding to β-tubulin
Fortin, Sebastien,Moreau, Emmanuel,Patenaude, Alexandre,Desjardins, Michel,Lacroix, Jacques,Rousseau, Jean L.C.,C-Gaudreault, Rene
, p. 1430 - 1438 (2008/02/13)
Tubulin is the target of many anticancer drugs, including N-phenyl-N′-(2-chloroethyl)urea (CEU). Unlike most anti-β-tubulin agents, CEUs are protein monoalkylating agents binding through their N′-(2-chloroethyl)urea moiety to an amino acid nearby the colchicine-binding site on β-tubulin isoform-2. Following the previously synthesized and attractive N-(3-ω-hydroxyalkylphenyl)-N′-(2-chloroethyl)urea that exhibited growth inhibitory activity at the nanomolar level, we investigated the importance of lower alkyl and alkoxy groups to evaluate the effect of hydroxylated group and chain length on both cell growth inhibition and the mechanism of action of CEU. Here, we describe the preparation of two new series of CEU and show that the most potent CEU derivatives beside the ω-hydroxylated 1f were 2f and 3e, respectively. We have confirmed that the pentyl substituted CEUs 1f, 2f, and 3e are still covalently binding to β-tubulin and still arrest cell division in G2/M phase. Crown Copyright
ORALLY AVAILABLE SPHINGOSINE 1-PHOSPHATE RECEPTOR AGONISTS AND ANTAGONISTS
-
Page/Page column 108-109, (2008/06/13)
The present invention relates to S1P analogs that have activity as S1Preceptor modulating agents and the use of such compounds to treat diseases associated with inappropriate S1P receptor activity. The compounds have the general structure (I) wherein R11 is C5-C18 alkyl or C5-C18 alkenyl; Q is selected from the group consisting of C3-C6 optionally substituted cycloalkyl, C3-C6 optionally substituted heterocyclic, C3-C6 optionally substituted aryl C3-C6 optionally substituted heteroaryl and; R2 is selected from the group consisting of H, C1-C4 alkyl, (C1-C4 alkyl)OH and (C1-C4 alkyl)NH2; R23 is H or C1-C4 alkyl, and R15 is a phosphonate ester or a phosphate ester or a pharmaceutically acceptable salt or tautomer thereof.
