- Phosphine-Functionalized Chitosan Microparticles as Support Materials for Palladium Nanoparticles in Heck Reactions
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Herein, we investigated the activation and stabilization of Pd nanoparticles using microparticles of chitosan-functionalized with phosphine moieties. The catalytic activity of the prepared material was assessed in a series of Heck reactions, which demonst
- Biajoli, André F. P.,Fajardo, André R.,Lemos, Thalia S. A.,de Souza, Jaqueline F.
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- Synthesis of novel 1-phenyl-benzopyrrolizidin-3-one derivatives and evaluation of their cytoneuroprotective effects against NMDA-induced injury in PC12 cells
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A range of novel 1-phenyl-benzopyrrolizidin-3-one derivatives were synthesized and evaluated for neuroprotective effects against N-methyl-?-aspartate (NMDA)-induced injury in PC12 cells. Interestingly, derivatives that 1-phenyl moiety bearing electron-donating group, especially benzyloxy, and the trans-forms exhibited better protective activity against NMDA-induced neurotoxicity. Compound 11 m demonstrated the best neuroprotective potency and shown a dose-dependent prevention. The increased intracellular calcium (Ca2+) influx caused by NMDA in PC12 cells was reversed in the case of compound 11 m pretreatment at 15 μM. These results suggested that the synthesized 1-phenyl-benzopyrrolizidin-3-one derivatives exerted neuroprotective effect on NMDA-induced excitotoxicity in PC12 cells associated with inhibition of Ca2+ overload and can be further optimized for the development of neuroprotective agents.
- Cao, Jiafu,Li, Qiji,Liao, Xiu,Wang, Enhua,Wang, Li,Yang, Juan,Yang, Lishou,Yang, Qian,Yang, Xiaosheng,Yang, Yan
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- HETEROCYCLIC COMPOUNDS FOR MODULATING NR2F6
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The present disclosure relates to compounds capable of modulating the activity of NR2F6. The compounds of the disclosure may be used in methods for the prevention and/or the treatment of diseases and disorders associated with modulating NR2F6 activity.
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Paragraph 00393; 00397
(2021/09/04)
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- TREATMENT OF DISORDERS ASSOCIATED WITH OXIDATIVE STRESS AND COMPOUNDS FOR SAME
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The present invention relates to the treatment of disorders associated with oxidative stress including neuropathic pain and small synthetically derived compounds for treating such disorders.
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Page/Page column 49; 52; 54
(2021/09/17)
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- Oxidative esterification of alcohols by a single-side organically decorated Anderson-type chrome-based catalyst
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The direct esterification of alcohols with non-noble metal-based catalytic systems faces great challenges. Here, we report a new chrome-based catalyst stabilized by a single pentaerythritol decorated Anderson-type polyoxometalate, [N(C4H9)4]3[CrMo6O18(OH)3C{(OCH2)3CH2OH}], which can realize the efficient transformation from alcohols to esters by H2O2oxidation in good yields and high selectivity without extra organic ligands. A variety of alcohols with different functionalities including some natural products and pharmaceutical intermediates are tolerated in this system. The chrome-based catalyst can be recycled several times and still keep the original configuration and catalytic activity. We also propose a reasonable catalytic mechanism and prove the potential for industrial applications.
- Wang, Jingjing,Jiang, Feng,Tao, Chaofu,Yu, Han,Ruhlmann, Laurent,Wei, Yongge
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supporting information
p. 2652 - 2657
(2021/04/21)
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- Nickel-Catalyzed Alkyl-Alkyl Cross-Electrophile Coupling Reaction of 1,3-Dimesylates for the Synthesis of Alkylcyclopropanes
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Cross-electrophile coupling reactions of two Csp3-X bonds remain challenging. Herein we report an intramolecular nickel-catalyzed cross-electrophile coupling reaction of 1,3-diol derivatives. Notably, this transformation is utilized to synthesize a range of mono- and 1,2-disubstituted alkylcyclopropanes, including those derived from terpenes, steroids, and aldol products. Additionally, enantioenriched cyclopropanes are synthesized from the products of proline-catalyzed and Evans aldol reactions. A procedure for direct transformation of 1,3-diols to cyclopropanes is also described. Calculations and experimental data are consistent with a nickel-catalyzed mechanism that begins with stereoablative oxidative addition at the secondary center.
- Chen, Pan-Pan,Hong, Xin,Jarvo, Elizabeth R.,McGinnis, Tristan M.,Sanford, Amberly B.,Thane, Taylor A.
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supporting information
(2020/03/23)
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- Design and synthesis of bitopic 2-phenylcyclopropylmethylamine (pcpma) derivatives as selective dopamine d3 receptor ligands
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2-Phenylcyclopropylmethylamine (PCPMA) analogues have been reported as selective serotonin 2C agonists. On the basis of the same scaffold, we designed and synthesized a series of bitopic derivatives as dopamine D3R ligands. A number of these new compounds show a high binding affinity for D3R with excellent selectivity. Compound (1R,2R)-22e and its enantiomer (1S,2S)-22e show a comparable binding affinity for the D3R, but the former is a potent D3R agonist, while the latter acts as an antagonist. Molecular docking studies revealed different binding poses of the PCPMA moiety within the orthosteric binding pocket of the D3R, which might explain the different functional profiles of the enantiomers. Compound (1R,2R)-30q shows a high binding affinity for the D3R (Ki = 2.2 nM) along with good selectivity, as well as good bioavailability and brain penetration properties in mice. These results reveal that the PCPMA scaffold may serve as a privileged scaffold for the design of aminergic GPCR ligands.
- Tan, Liang,Zhou, Qingtong,Yan, Wenzhong,Sun, Jian,Kozikowski, Alan P.,Zhao, Suwen,Huang, Xi-Ping,Cheng, Jianjun
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p. 4579 - 4602
(2020/06/08)
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- C–C Cross-Coupling Reactions of Organosilanes with Terminal Alkenes and Allylic Acetates Using PdII Catalyst Supported on Starch Coated Magnetic Nanoparticles
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Starch coated magnetic nanoparticles supported palladium catalyst has been explored to perform C–C cross coupling reactions, such as oxidative Heck coupling and Tsuji–Trost allylic coupling using organosilicon compounds as one of the coupling partners. The biopolymer coated magnetic catalyst was very easy to recover magnetically and was efficiently recycled in the subsequent batches. All the reactions were performed in air and thus the necessity of air and moisture free reaction condition is avoided. The present protocols show wide substrate scope and good yields of the products.
- Patra, Debabrata,Panja, Subir,Saha, Amit
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p. 878 - 883
(2020/02/13)
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- Palladium-Based Catalysts Supported by Unsymmetrical XYC–1 Type Pincer Ligands: C5 Arylation of Imidazoles and Synthesis of Octinoxate Utilizing the Mizoroki–Heck Reaction
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A series of new unsymmetrical (XYC–1 type) palladacycles (C1–C4) were designed and synthesized with simple anchoring ligands L1–4H (L1H = 2-((2-(4-methoxybenzylidene)-1-phenylhydrazinyl)methyl)pyridine, L2H = N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl)aniline, L3H = N,N-diethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl) aniline and L4H = 4-(4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono) methyl)phenyl)morpholine H = dissociable proton). Molecular structure of catalysts (C1–C4) were further established by single X-ray crystallographic studies. The catalytic performance of palladacycles (C1–C4) was explored with the direct Csp2–H arylation of imidazoles with aryl halide derivatives. These palladacycles were also applied for investigating of Mizoroki–Heck reactions with aryl halides and acrylate derivatives. During catalytic cycle in situ generated Pd(0) nanoparticles were characterized by XPS, SEM and TEM analysis and possible reaction pathways were proposed. The catalyst was employed as a pre-catalyst for the gram-scale synthesis of octinoxate, which is utilized as a UV-B sunscreen agent.
- Maji, Ankur,Singh, Ovender,Singh, Sain,Mohanty, Aurobinda,Maji, Pradip K.,Ghosh, Kaushik
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p. 1596 - 1611
(2020/04/29)
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- Highly Regio- A nd Enantioselective Hydrogenation of Conjugated α-Substituted Dienoic Acids
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Highly regio- A nd enantioselective hydrogenation of conjugated α-substituted dienoic acids was realized for the first time using Trifer-Rh complex, providing a straightforward method for the synthesis of chiral α-substituted ?,?′-unsaturated acids. DFT calculations revealed N+H-O hydrogen bonding interaction is formed to stabilize the transition state and the coordination of 4,5-double bond to Rh(III) center would facilitate the reductive elimination process. This hydrogenation provided a gram-scale synthesis of the precursor of sacubitril.
- Liu, Xian,Liu, Song,Wang, Quanjun,Zhou, Gang,Yao, Lin,Ouyang, Qin,Jiang, Ru,Lan, Yu,Chen, Weiping
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supporting information
p. 3149 - 3154
(2020/04/09)
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- Synthesis and biological evaluation of celastrol derivatives as anti-ovarian cancer stem cell agents
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Ovarian cancer is associated with a high percentage of recurrence of tumors and resistance to chemotherapy. Cancer stem cells (CSCs) are responsible for cancer progression, tumor recurrence, metastasis, and chemoresistance. Thus, developing CSC-targeting therapy is an urgent need in cancer research and clinical application. In an attempt to achieve potent and selective anti-CSC agents, a series of celastrol derivatives with cinnamamide chains were synthesized and evaluated for their anti-ovarian cancer activities. Most of the compounds exhibited stronger antiproliferative activity than celastrol, and celastrol derivative 7g with a 3,4,5-trimethoxycinnamamide side chain was found to be the most potent antiproliferative agent against ovarian cancer cells with an IC50 value of 0.6 μM. Additionally, compound 7g significantly inhibited the colony formation ability and reduced the number of tumor spheres. Furthermore, compound 7g decreased the percentage of CD44+, CD133+ and ALDH+ cells. Thus, compound 7g is a promising anti-CSC agent and could serve as a candidate for the development of new anti-ovarian cancer drugs.
- Li, Xiaojing,Ding, Jie,Li, Ning,Liu, Wenxia,Ding,Zheng, Huijuan,Ning, Yanyan,Wang, Hongmin,Liu, Renmin,Ren, Shaoda
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p. 667 - 679
(2019/07/05)
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- Copper-Catalyzed 1,2-Methoxy Methoxycarbonylation of Alkenes with Methyl Formate
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Reported here is a copper-catalyzed 1,2-methoxy methoxycarbonylation of alkenes by an unprecedented use of methyl formate as a source of both the methoxy and the methoxycarbonyl groups. This reaction transforms styrene and its derivatives into value-added β-methoxy alkanoates and cinnamates, as well as medicinally important five-membered heterocycles, such as functionalized tetrahydrofurans, γ-lactones, and pyrrolidines. A ternary β-diketiminato-CuI-styrene complex, fully characterized by NMR spectroscopy and X-ray crystallographic analysis, is capable of catalyzing the same transformation. These findings suggest that pre-coordination of electron-rich alkenes to copper might play an important role in accelerating the addition of nucleophilic radicals to electron-rich alkenes, and could have general implications in the design of novel radical-based transformations.
- Budai, Balázs,Leclair, Alexandre,Wang, Qian,Zhu, Jieping
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p. 10305 - 10309
(2019/06/27)
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- Mizoroki–Heck cross-coupling reactions using palladium immobilized on DABCO-functionalized silica
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A heterogeneous palladium catalyst supported on silica modified by DABCO has been prepared by post-synthetic modification of silica gel. This heterogeneous catalytic system exhibits high activity and stability in the Mizoroki–Heck cross-coupling reaction of various aryl halides with olefins. The reaction proceeds efficiently under efficiently under mild mild reaction conditions and high yield, with the formation of E-isomers selectively. Moreover, we successfully established a gram-scale synthesis, and the catalyst was reused for up to ten catalytic cycles.
- Jadhav, Sanjay,Patil, Seema,Kumbhar, Arjun,Kamble, Santosh,Salunkhe, Rajashri
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p. 507 - 514
(2019/04/25)
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- Novel multi-dentate phosphines for Pd-catalyzed alkoxycarbonylation of alkynes promoted by H2O additive
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A series of novel multi (bi-/tri-/tetra-)-dentate phosphines with good robustness against water and oxygen were synthesized and fully characterized. It was found that the developed ionic tri-dentate phosphine (L2′) enabled Pd-catalyzed alkoxycarbonylation of alkynes most efficiently while H2O was used as an additive instead of acid. As for L2′, its unique steric configuration with two types of potential P-P chelation modes (P?P distance of 4.31 ? and 4.36 ? respectively) to Pd-centre rendered the corresponding Pd-catalyst high activity and good stability for alkoxycarbonylation of alkynes. The in situ FT-IR analysis also verified that the formation and stability of Pd–H active species were greatly facilitated with the presence of L2′ as well as H2O additive. In addition, as an ionic phosphine, L2′ based PdCl2(MeCN)2 system immobilized in RTIL of [Bmim]NTf2 could be recycled for 7 runs without obvious activity loss or metal leaching.
- Yang, Da,Liu, Lei,Wang, Dong-Liang,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
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p. 236 - 244
(2019/02/19)
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- Bis(imidazolium) chloride based on 1,2-phenylenediamine as efficient ligand precursor for palladium-catalyzed Mizoroki-Heck cross-coupling reaction
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Bis(imidazolium) chlorides based on 1,2-phenylenediamine were introduced as efficient ligand precursors in the Pd-catalyzed Mizoroki-Heck cross-coupling reactions of substituted aryl halides with activated alkenes to afford the corresponding functionalized alkenes. While high to excellent yields (78–96%) were obtained with aryl bromides, moderate yields (51–59%) were achieved for aryl chlorides in this protocol.
- Takallou, Ahmad,Habibi, Azizollah,Halimehjani, Azim Ziyaei,Balalaie, Saeed
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supporting information
p. 24 - 28
(2019/03/21)
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- Synthesis and discovery of 18β-glycyrrhetinic acid derivatives inhibiting cancer stem cell properties in ovarian cancer cells
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Despite advances in ovarian cancer treatment, the five-year overall survival rate is less than 30% with the presence of cancer stem cells (CSCs). To develop CSC-targeting therapy, a series of 18β-glycyrrhetinic acid (GA) derivatives containing cinnamamide moiety have been designed, synthesized, and screened for their antiproliferative activity in SKOV3 and OVCAR3 cells. Most of the compounds exhibited stronger antiproliferative activity than GA, and compound 7c was the most active one. Further biological studies showed that compound 7c could induce apoptosis and suppress migration. In addition, compound 7c could not only observably decrease the colony formation and sphere formation ability, but also significantly reduce the CD44+, CD133+, and ALDH+ subpopulation in SKOV3 and OVCAR3 cells. In conclusion, these results indicate that compound 7c is a promising anti-CSC agent for further anti-ovarian cancer studies.
- Li, Xiaojing,Liu, Yihua,Wang, Na,Liu, Yuyu,Wang, Shuai,Wang, Hongmin,Li, Aihua,Ren, Shaoda
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p. 27294 - 27304
(2019/09/12)
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- PdII/Novel Chiral Cinchona Alkaloid Oxazoline-Catalyzed Enantioselective Oxidative Cyclization of Aromatic Alkenyl Amides
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A highly enantioselective PdII-catalyzed aza-Wacker oxidation tandem cyclization of aromatic nitrogen-containing dienes has been achieved in the presence of novel chiral cinchona alkaloid oxazoline ligands for the first time, affording chiral dihydroindole nitrogen-containing polycyclic compounds with good yields (up to 83 %), high diastereoselectivities (> 95:5 dr), and excellent enantioselectivities (up to 97 % ee).
- Tian, Qinqin,Liu, Yulong,Wang, Xiaoyun,Wang, Xie,He, Wei
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supporting information
p. 3850 - 3855
(2019/06/08)
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- Selective Palladium-Catalyzed Carbonylation of Alkynes: An Atom-Economic Synthesis of 1,4-Dicarboxylic Acid Diesters
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A class of novel diphosphine ligands bearing pyridine substituents was designed and synthesized for the first time. The resulting palladium complexes of L1 allow for chemo- and regioselective dialkoxycarbonylation of various aromatic and aliphatic alkynes affording a wide range of 1,4-dicarboxylic acid diesters in high yields and selectivities. Kinetic studies suggest the generation of 1,4-dicarboxylic acid diesters via cascade hydroesterification of the corresponding alkynes. Based on these investigations, the chemo- and regioselectivities of alkyne carbonylations can be controlled as shown by switching the ligand from L1 to L3 or L9 to give α,β-unsaturated esters.
- Liu, Jiawang,Dong, Kaiwu,Franke, Robert,Neumann, Helfried,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 10282 - 10288
(2018/08/03)
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- Oxidative Functionalization of Cinnamaldehyde Derivatives: Control of Chemoselectivity by Organophotocatalysis and Dual Organocatalysis
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The catalytic and chemoselective oxidation of cinnamaldehyde derivatives having a C=C bond and formyl group was studied by using two organocatalysts. The visible-light-induced catalysis using rhodamine 6G as an organophotocatalyst promoted the methoxyhydr
- Yoshioka, Eito,Inoue, Maika,Nagoshi, Yuka,Kobayashi, Ayumi,Mizobuchi, Rumiko,Kawashima, Akira,Kohtani, Shigeru,Miyabe, Hideto
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p. 8962 - 8970
(2018/07/15)
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- The Catalytic Asymmetric Mukaiyama–Michael Reaction of Silyl Ketene Acetals with α,β-Unsaturated Methyl Esters
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α,β-Unsaturated esters are readily available but challenging substrates to activate in asymmetric catalysis. We now describe an efficient, general, and highly enantioselective Mukaiyama–Michael reaction of silyl ketene acetals with α,β-unsaturated methyl esters that is catalyzed by a silylium imidodiphosphorimidate (IDPi) Lewis acid.
- Gatzenmeier, Tim,Kaib, Philip S. J.,Lingnau, Julia B.,Goddard, Richard,List, Benjamin
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supporting information
p. 2464 - 2468
(2018/02/06)
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- Synthesis and biological evaluation of phloroglucinol derivatives possessing α-glycosidase, acetylcholinesterase, butyrylcholinesterase, carbonic anhydrase inhibitory activity
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A series of novel phloroglucinol derivatives were designed, synthesized, characterized spectroscopically and tested for their inhibitory activity against selected metabolic enzymes, including α-glycosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and human carbonic anhydrase I and II (hCA I and II). These compounds displayed nanomolar inhibition levels and showed Ki values of 1.14–3.92 nM against AChE, 0.24–1.64 nM against BChE, 6.73–51.10 nM against α-glycosidase, 1.80–5.10 nM against hCA I, and 1.14–5.45 nM against hCA II.
- Burmaoglu, Serdar,Yilmaz, Ali O.,Taslimi, Parham,Algul, Oztekin,Kilic, Deryanur,Gulcin, Ilhami
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- Synthesis and antibacterial evaluation of novel 11-O-aralkylcarbamoyl-3-O-descladinosylclarithromycin derivatives
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A series of novel 11-O-aralkylcarbamoyl-3-O-descladinosylclarithromycin derivatives were designed, synthesized and evaluated for their in vitro antibacterial activity. The results showed that the majority of the target compounds displayed potent activity against erythromycin-susceptible S. pyogenes, erythromycin-resistant S. pneumoniae A22072 expressing the mef gene and S. pneumoniae AB11 expressing the mef and erm genes. Besides, most of the target compounds exhibited moderate activity against erythromycin-susceptible S. aureus ATCC25923 and B. subtilis ATCC9372. In particular, compounds 11a, 11b, 11c, 11e, 11f and 11h were found to exert favorable antibacterial activity against erythromycin-susceptible S. pyogenes with the MIC values of 0.015–0.125 μg/mL. Furthermore, compounds 10e, 11a, 11b and 11c showed superior activity against erythromycin-resistant S. pneumoniae A22072 with the MIC values of 0.25–0.5 μg/mL. Additionally, compound 11c was the most effective against all the erythromycin-resistant S. pneumoniae strains (A22072, B1 and AB11), exhibiting 8-, 8- and 32-fold more potent activity than clarithromycin, respectively.
- Jia, Li,Wang, Yinhu,Wang, Yanxia,Qin, Yinhui,Hu, Chaoyu,Sheng, Juzheng,Ma, Shutao
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supporting information
p. 2471 - 2476
(2018/06/06)
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- SUBSTITUTED DIHYDROPYRROLOPYRAZOLE COMPOUND
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Provided is a compound represented by formula (I) or a pharmacologically acceptable salt thereof: wherein L1 is an optionally substituted C1-6 alkylene group or the like, L2 is a single bond or the like, L3 is a single bond or the like, R1, R2, and R3 are each independently an optionally substituted C1-4 alkyl group or the like, R4 is a hydrogen atom or the like, and R5 is a hydrogen atom or the like.
- -
-
Paragraph 1024-1026
(2017/09/12)
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- Oxidative coupling of Michael acceptors with aryl nucleophiles produced through rhodium-catalyzed C-C bond activation
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Utilizing rhodium catalysis, aryl nucleophiles generated via carbon-carbon single bond activation successfully undergo oxidative coupling with Michael acceptors. The reaction scope encompasses a broad range of nucleophiles generated from quinolinyl ketones as well as a series of electron deficient terminal alkenes, illustrating the broad potential of intersecting carbon-carbon bond activation with synthetically useful coupling methodologies. The demonstrated oxidative coupling produces a range of cinnamyl derivatives, several of which are challenging to prepare via conventional routes.
- Gregerson, Caroline E.,Trentadue, Kathryn N.,Phipps, Erik J. T.,Kirsch, Janelle K.,Reed, Katherine M.,Dyke, Gabriella D.,Jansen, Jacob H.,Otteman, Christian B.,Stachowski, Jessica L.,Johnson, Jeffrey B.
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supporting information
p. 5944 - 5948
(2017/07/25)
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- An efficient palladium catalyzed Mizoroki-Heck cross-coupling in water
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The homogeneous Pd-catalysed Mizoroki-Heck coupling reaction was successfully performed in water in the absence of any additives under aerobic conditions. The various key reaction parameters that affect the yield of the desired cross-coupling product were optimized. The Pd(PPh3)4/Et3N/H2O/98 °C catalyst system was found to be highly active (TOF = 12 to 14 h-1) towards achieving excellent yield of the Mizoroki-Heck coupling products for a wide range of electron-withdrawing as well as electron-donating aryl bromides and chlorides in the shortest reaction time. Pd(PPh3)4 catalyst deactivation during the Mizoroki-Heck coupling reaction was investigated and to evolve a strategy for achieving ten times Pd-metal recyclability without appreciable loss of its activity. Thus, the proposed mechanism provides access to a variety of olefins in aqueous medium, making this protocol eco-friendly.
- Jadhav, Sanjay N.,Rode, Chandrashekhar V.
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supporting information
p. 5958 - 5970
(2017/12/26)
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- Hg(II) and Pd(II) complexes with a new selenoether bridged biscarbene ligand: Efficient mono- and bis-arylation of methyl acrylate with a pincer biscarbene Pd(II) precatalyst
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Two equivalents of 1-benzyl-3-bromoethylbenzimidazolium bromide couple with Na2Se to produce the first selenoether bridged bis-benzimidazolium salt (LH2)Br2. The nitrate (LH2)(NO3)2 and tetrafluoroborate (LH2)(BF4)2 salts were also synthesized from (LH2)Br2. The reaction of Hg(OAc)2 with (LH2)Br2 gave the first pseudo pincer carbene mercury complex, [Hg(L-κ2C)][HgBr4] (C1). Different complexes of Pd(ii) with selenoether bridged carbene were obtained using (LH2)Br2 and (LH2)(NO3)2. Syntheses of these complexes were dependent on the counter anion and the temperature. Thus, the pincer type ionic complex [PdBr(L-κ3CSeC)]Br (C2) was isolated at 80 °C and the pseudo pincer type neutral complex cis-[PdBr2(L-κ2C)] (C3) was isolated at room temperature from (LH2)Br2 and Pd(OAc)2 in DMSO. The nitrate precursor (LH2)(NO3)2 on palladation with Pd(OAc)2 afforded [Pd(L-κ4CBzCSeC)]NO3 (C4) showing an unprecedented intramolecular metallation at the ortho position of the benzyl wingtip of the benzimidazole moiety. The ligand salts and metal complexes have been characterized using HRMS, heteronuclear NMR and IR spectroscopy. Single crystal X-ray structures of the ligand salts (LH2)Br2 and (LH2)(BF4)2 and complexes C1-C4 have also been elucidated. Complex C2 showed good activity for C-C coupling in the mono-Heck reaction of methyl acrylate and arylbromides. Interestingly, the less common bis-arylation was also observed with deactivated arylbromides as the result of double-Heck coupling.
- Rishu,Prashanth, Billa,Bawari, Deependra,Mandal, Ushnish,Verma, Aditya,Choudhury, Angshuman Roy,Singh, Sanjay
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supporting information
p. 6291 - 6302
(2017/07/10)
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- An ionic liquid catalyzed probase method for one-pot synthesis of α,β-unsaturated esters from esters and aldehydes under mild conditions
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A one-pot synthesis of α,β-unsaturated esters from unactivated esters and aldehydes using strong bases, such as sodium alkoxide and potassium tert-butoxide, was reported. However, the ionic liquid (IL) catalyzed probase method for producing α,β-unsaturated esters was not reported until now. In this work, a series of ILs with fluoride anions were firstly prepared and used as catalysts in combination with the probase N,O-bis(trimethylsilyl) acetamide (BSA) for the α,β-unsaturated esters synthesis. This process could also be promoted through the introduction of another IL with Lewis acid sites. The yield and selectivity of the product could reach up to 84.2% and 95.0%, respectively, when [Bmim]F was used in combination with [Bmim]Cl/AlCl3 (the molar fraction of AlCl3 is 0.67). The mechanism investigation through GC-MS indicates that BSA would convert into onium amide, which acted as a strong base for α-H abstraction, with the catalysis of [Bmim]F. Meanwhile, [Bmim]Cl/AlCl3 played an important role in the condensation step between enolates and aldehydes. On the basis of mechanism insights, kinetic and thermodynamic studies were also carried out for a better understanding of this new route.
- Wang, Gang,Xu, Yiming,Zhang, Suojiang,Li, Zengxi,Li, Chunshan
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p. 4838 - 4848
(2017/10/23)
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- Palladium nanoparticles immobilized on amphiphilic and hyperbranched polymer-functionalized magnetic nanoparticles: An efficient semi-heterogeneous catalyst for Heck reaction
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To address the obstacles facing the use of palladium-based homogeneous and heterogeneous catalysts in C─C cross-coupling reactions, a novel semi-heterogeneous support was developed based on hyperbranched poly(ethylene glycol)-block-poly(citric acid)-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@PCA-b-PEG). Because of the surface modification of the Fe3O4 nanoparticles with amphiphilic and hyperbranched polymers (PCA-b-PEG), these hybrid materials are not only soluble in a wide range of solvents (e.g. water, ethanol and dimethylformamide) but also are able to trap Pd2+ ions via complex formation of free carboxyl groups of the PCA dendrimer with metal ions. The reduction of trapped palladium ions in the dendritic shell of Fe3O4@PCA-b-PEG leads to immobilized palladium nanoparticles. The morphology and structural features of the catalyst were characterized using various microscopic and spectroscopic techniques. The catalyst was effectively used in the palladium-catalysed Mizoroki–Heck coupling reaction in water as a green solvent. In addition, the catalyst can be easily recovered from the reaction mixture by applying an external magnetic field and reused for more than ten consecutive cycles without much loss in activity, exhibiting an example of a sustainable and green methodology.
- Tabatabaei Rezaei, Seyed Jamal,Shamseddin, Azin,Ramazani, Ali,Mashhadi Malekzadeh, Asemeh,Azimzadeh Asiabi, Pegah
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- Synthesis of α-(Pentafluorosulfanyl)- and α-(Trifluoromethyl)-Substituted Carboxylic Acid Derivatives by Ireland-Claisen Rearrangement
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Earlier studies have shown that [3,3]-sigmatropic rearrangements of allyl esters are useful for the construction of fluorine-containing carboxylic acid derivatives. This paper describes the synthesis of 3-aryl-pent-4-enoic acid derivatives bearing either a pentafluorosulfanyl (SF5) or a trifluoromethyl (CF3) substituent in the 2-position by treatment of corresponding SF5- or CF3-acetates of p-substituted cinnamyl alcohols with triethylamine followed by trimethylsilyl triflate (TMSOTf). This Ireland-Claisen rearrangement delivered approximate 1:1 mixtures of syn/anti diastereoisomers due to tiny differences (3N) led to oligomerization of the cinnamyl SF5- and CF3-acetates. Treatment of the corresponding regioisomeric 1-phenyl-prop-2-en-1-yl acetates under the latter conditions resulted in [1,3]-sigmatropic rearrangement and subsequent oligomerization of the intermediately formed cinnamyl esters. When Et3N was added first followed by TMSOTf, no further reaction of the formed ester was detected.
- Dreier, Anna-Lena,Beutel, Bernd,Mück-Lichtenfeld, Christian,Matsnev, Andrej V.,Thrasher, Joseph S.,Haufe, Günter
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p. 1638 - 1648
(2017/02/10)
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- Compositions containing ionic liquids and their uses, in particular in organic synthesis
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An ionic liquid is used as liquid matrix for organic synthesis in homogeneous phase on soluble support, the ionic liquid being presented in liquid or solid form at ambient temperature, of formula A1+X1?, A1+ representing a cation, functional or non-functional, or a mixture of cations in which either none of the cations is functional or at least one of the cations is functional, and X1? an anion, functional or non-functional, or a mixture of anions in which either none of the anions is functional or at least one of the anions is functional.
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Page/Page column 45; 46; 47
(2016/10/17)
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- Leukotriene A4 hydrolase and cyclooxygense double target inhibitors and use thereof
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The invention discloses a double-target inhibitor for leukotriene A4 hydrolase and cyclooxygenase as well as a purpose of the double-target inhibitor. The double-target inhibitor is a compound shown in a general formula (I), wherein X1 and X2 are respectively and independently separated into hydrogen, halogen, alkyl or alkoxy; Y represents hydrogen, hydroxyl, halogen or alkyl; Z represents substituent groups at the fourth position and/or the fifth position of a benzoyl core benzene ring, and respectively represents hydrogen, halogen, amino, alkyl acylamino, alkyl substituted amino, trifluoromethyl or carboxyl alkyl acylamino; n is 2 to 4. The compound can be used for preparing medicine for treating, preventing or inhibiting inflammation such as arthritis and rheumatoid arthritis.
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Paragraph 0111; 0112; 0113
(2016/10/07)
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- Hydrogen Peroxide Promoted Mizoroki-Heck Reactions of Phenyldiazenes with Acrylates, Acrylamides, and Styrenes
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Mizoroki-Heck reactions, which are well-known for aryldiazonium salts and which have recently been described for arylhydrazines, have now been extended to phenyldiazenes. In situ generation of phenyldiazenes from azocarboxylates allowed clean and selective reactions with styrenes, acrylates, and acrylamides using palladium(II) acetate in the presence of silver(I) acetate or hydrogen peroxide as oxidant. Hydrogen peroxide was thereby shown to be a cheap and broadly applicable alternative for the established palladium-silver(I) system.
- Lasch, Roman,Fehler, Stefanie K.,Heinrich, Markus R.
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supporting information
p. 1586 - 1589
(2016/05/02)
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- Attractive aerobic access to the α,β-unsaturated acyl azolium intermediate: Oxidative NHC catalysis via multistep electron transfer
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To replace high molecular weight oxidants with air (O2) we introduce multistep electron transfer NHC catalysis. The method provides a general and selective oxidation of the α,β-unsaturated aldehyde derived homoenolate to the synthetically useful α,β-unsaturated acyl azolium intermediate. Several independent oxidative NHC-catalyzed reactions are viable with this strategy and the products can be isolated in high to excellent yields.
- Ta,Axelsson,Sundén
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supporting information
p. 686 - 690
(2016/02/12)
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- Catalytic asymmetric bromochlorination of aromatic allylic alcohols promoted by multifunctional Schiff base ligands
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It was found that the tridentate O,N,O-type Schiff base ligand bearing suitable substituents was a highly effective promoter in the catalytic asymmetric bromochlorination reaction, in which the corresponding aromatic bromochloroalcohols with vicinal halogen-bearing stereocenters were formed with perfect regioselectivity, with moderate to excellent enantioselectivities (up to 93% ee), and with good yields and chemoselectivities.
- Huang, Wei-Sheng,Chen, Li,Zheng, Zhan-Jiang,Yang, Ke-Fang,Xu, Zheng,Cui, Yu-Ming,Xu, Li-Wen
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supporting information
p. 7927 - 7932
(2016/08/30)
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- Lewis Base Activation of Silyl Acetals: Iridium-Catalyzed Reductive Horner-Wadsworth-Emmons Olefination
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A Lewis base promoted deprotonative pronucleophile addition to silyl acetals has been developed and applied to the iridium-catalyzed reductive Horner-Wadsworth-Emmons (HWE) olefination of esters and the chemoselective reduction of the resulting enoates. Lewis base activation of silyl acetals generates putative pentacoordinate silicate acetals, which fragment into aldehydes, silanes, and alkoxides in situ. Subsequent deprotonative metalation of phosphonate esters followed by HWE with aldehydes furnishes enoates. This operationally convenient, mechanistically unique protocol converts the traditionally challenging aryl, alkenyl, and alkynyl esters to homologated enoates at room temperature within a single vessel.
- Dakarapu, Udaya Sree,Bokka, Apparao,Asgari, Parham,Trog, Gabriela,Hua, Yuanda,Nguyen, Hiep H.,Rahman, Nawal,Jeon, Junha
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supporting information
p. 5792 - 5795
(2015/12/11)
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- Palladium-Catalyzed Arylation of Olefins by Triarylphosphines via C-P Bond Cleavage
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C-H Arylation of olefins by triarylphosphines via C-P bond cleavage has been achieved with either Pd0 or PdII catalysts. A variety of olefins and triarylphosphines are tolerated, and we inferred that both Pd0 and PdII could function directly without pre-oxidation or pre-reduction.
- Lu, Dapeng,Xu, Yu,Liu, Wenjing,Guo, Lijuan,Sun, Xingxia
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p. 116 - 122
(2015/10/19)
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- An Abnormal N-Heterocyclic Carbene-Based Palladium Dimer: Aqueous Oxidative Heck Coupling under Ambient Temperature
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Herein we report the synthesis of a new abnormal N-heterocyclic carbene (aNHC)-based ligand and its use in synthesizing an acetate bridged C-H activated palladium dimer (1). In complex 1, the carbene ligand displays an abnormal mode of binding with the palladium(II) ion. We used complex 1 as a catalyst for the oxidative Heck coupling reaction of arylboronic acids with electron-deficient as well as electron-rich olefins at ambient temperature in water to produce selectively the β-arylated products in good to excellent yields.
- Hota, Pradip Kumar,Vijaykumar, Gonela,Pariyar, Anand,Sau, Samaresh Chandra,Sen, Tamal K.,Mandal, Swadhin K.
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supporting information
p. 3162 - 3170
(2015/11/03)
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- TRPA1 antagonists
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Compounds of formula (I) wherein R1, R2, R3, m, and Y are defined in the specification are TRPA1 antagonists. Compositions comprising such compounds and methods for treating conditions and disorders using such compounds
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Page/Page column 30
(2015/09/22)
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- Scope and Limitation of the Microwave-Assisted Catalytic Wittig Reaction
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We have developed a microwave-assisted catalytic Wittig reaction. In this paper, we give full account of the scope and limitations of this reaction. A screening of various commercially available phosphine oxides as precatalysts revealed Bu3P=O to be the most promising candidate. We tested 10 silanes for the in situ reduction of the phosphine oxide to generate Bu3P as the actual catalyst. Different epoxides were tested as masked bases. In this context, cyclohexene oxide as well as butylene oxide proved to be suitable. The reaction could be carried out at 125 C, but higher yields and E/Z selectivities were obtained at 150 °C. Under the optimised reaction conditions, more than 40 examples for the conversion of various aldehydes into the corresponding alkenes are reported. The products were obtained in yields of up to 88 with high E selectivities. Moreover, we also describe the further screening of several chiral phosphines as catalysts for the microwave-assisted enantioselective catalytic Wittig reaction. The scope and limitations of the microwave-assisted catalytic Wittig reaction have been evaluated with respect to the catalyst, silane, solvent, reaction conditions, and substrates.
- Hoffmann, Marcel,Deshmukh, Sunetra,Werner, Thomas
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p. 4532 - 4543
(2015/07/27)
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- The palladium slow-release pre-catalysts and nanoparticles in the "phosphine-free" Mizoroki-Heck and Suzuki-Miyaura reactions
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The Mizoroki-Heck reaction of electronrich aryl iodides was studied using a phosphine-free catalytic system with a broad range of pre-catalysts of varied stability and structure based on organoselenium chelators. The application of the "mercury test" by observing the response of the catalytic systems studied not only to the addition, but also to the withdrawal of Hg allowed us to establish a critical role of nanoparticles in the operation of the phos-phine-free catalytic systems. A three-stage mechanistic scheme involving a slow stage served by mononuclear Pd species, and the main fast stage served by Pd nanoparticles, and terminated by the nanoparticle decay is proposed as a general mechanistic paradigm for the phosphine-free Mizoroki-Heck and the related Suzuki-Miyaura reactions.
- Sigeev, Alexander S.,Peregudov, Alexander S.,Cheprakov, Andrei V.,Beletskaya, Irina P.
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p. 417 - 429
(2015/02/19)
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- KDM1A INHIBITORS FOR THE TREATMENT OF DISEASE
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Disclosed herein are new compounds and compositions and their application as pharmaceuticals for the treatment of diseases. Methods of inhibition of KDMIA, and methods of increasing gamma globin gene expression in a human or animal subject are also provided for the treatment diseases such as sickle cell disease.
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Paragraph 0264
(2014/10/18)
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- α-ketophosphonates as ester surrogates: Isothiourea-catalyzed asymmetric diester and lactone synthesis
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Isothiourea HBTM-2.1 catalyzes the asymmetric Michael addition/ lactonization of aryl- and alkenylacetic acids using α-keto-β, γ-unsaturated phosphonates as α,β-unsaturated ester surrogates, giving access to a diverse range of stereodefined lactones or enantioenriched functionalized diesters upon ring-opening.
- Smith, Siobhan R.,Leckie, Stuart M.,Holmes, Reuben,Douglas, James,Fallan, Charlene,Shapland, Peter,Pryde, David,Slawin, Alexandra M. Z.,Smith, Andrew D.
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supporting information
p. 2506 - 2509
(2014/05/20)
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- Photodriven Transfer Hydrogenation of Olefins
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An improved practical method for the photodriven diimide reduction of olefins was investigated. This catalyst-free procedure proceeds at ambient temperature, utilizes air as oxidant and a lower hydrazine loading, and produces inert nitrogen gas as the sole byproduct. Several functional groups were tolerated, and in some cases, the reaction was chemoselective. Challenging substrates such as cinnamate ester derivatives and trans-stilbene were reduced in excellent yields. The small amount of UVA rays emitted from a household compact fluorescent light bulb was proposed to enable the cis/trans isomerization of the diimide and to promote the loss of hydrogen from the diimide.
- Leow, Dasheng,Chen, Ying-Ho,Hung, Tzu-Hang,Su, Ying,Lin, Yi-Zhen
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supporting information
p. 7347 - 7352
(2016/02/18)
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- Pd nanoparticles in the thermoregulated ionic liquid and organic biphasic system: An efficient and recyclable catalyst for heck reaction
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A thermoregulated ionic liquid and organic biphasic system composed of ionic liquid [CH3(OCH2CH2)16N +Et3][CH3SO3 -] (IL PEG750) with ILPEG750-stabilized Pd nanoparticles and organic solvents, which allows for not only a highly efficient homogeneous catalytic reaction, but also an easy biphasic separation and reuse of catalyst attributed to the thermoregulated phase-transition property of the system, was employed for Heck reaction. The ILPEG750-stabilized Pd nanoparticle catalyst exhibited high efficiency, more importantly, after reaction the Pd nanoparticle catalyst could be separated from products by simple phase separation and recycled for six times without evident loss of activity. Graphical Abstract: A thermoregulated ionic liquid and organic biphasic system containing [CH3(OCH2CH2)16N +Et3][CH3SO 3 - ] (ILPEG750)-stabilized Pd nanoparticles was applied to Heck reaction for the first time. The Pd nanoparticle catalyst exhibited high efficiency and good recyclability.[Figure not available: see fulltext.]
- Zeng, Yan,Wang, Yanhua,Xu, Yicheng,Song, Ying,Jiang, Jingyang,Jin, Zilin
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p. 200 - 205
(2013/03/13)
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- An improved catalyst system for the Pd-catalyzed fluorination of (hetero)aryl triflates
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The stable Pd(0) species [(1,5-cyclooctadiene)(L·Pd)2] (L = AdBrettPhos) has been prepared and successfully evaluated as a precatalyst for the fluorination of aryl triflates derived from biologically active and heteroaryl phenols, challenging substrates for our previously reported catalyst system. Additionally, this precatalyst activates at room temperature under neutral conditions, generates 1,5-cyclooctadiene as the only byproduct, and leads to overall cleaner reaction profiles.
- Lee, Hong Geun,Milner, Phillip J.,Buchwald, Stephen L.
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supporting information
p. 5602 - 5605
(2013/11/19)
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- Copper-catalyzed decarboxylative trifluoromethylation of allylic bromodifluoroacetates
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The development of new synthetic fluorination reactions has important implications in medicinal, agricultural, and materials chemistries. Given the prevalence and accessibility of alcohols, methods to convert alcohols to trifluoromethanes are desirable. However, this transformation typically requires four-step processes, specialty chemicals, and/or stoichiometric metals to access the trifluoromethyl-containing product. A two-step copper-catalyzed decarboxylative protocol for converting allylic alcohols to trifluoromethanes is reported. Preliminary mechanistic studies distinguish this reaction from previously reported Cu-mediated reactions.
- Ambler, Brett R.,Altman, Ryan A.
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supporting information
p. 5578 - 5581
(2013/11/19)
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- Asymmetric synthesis of 2,4,5-trisubstituted Δ2- thiazolines
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Δ2-Thiazolines are interesting heterocycles that display a wide variety of biological characteristics. They are also common in chiral ligands used for asymmetric syntheses and as synthetic intermediates. Herein, we present asymmetric routes to
- Bengtsson, Christoffer,Nelander, Hanna,Almqvist, Fredrik
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p. 9916 - 9922
(2013/08/23)
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- Catalytic asymmetric cross-dehydrogenative coupling: Activation of C-H bonds by a cooperative bimetallic catalyst system
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A cooperative bimetallic catalyst system was applied in the catalytic asymmetric cross-dehydrogenative coupling of β-ketoesters and xanthene. Various optically active xanthene derivatives bearing a quaternary stereogenic carbon center were obtained in moderate to good yields (up to 90%) with excellent enantioselectivities (up to 99% ee). Meanwhile, a transition-state model was proposed to explain the origin of the asymmetric induction.
- Cao, Weidi,Liu, Xiaohua,Peng, Ruixue,He, Peng,Lin, Lili,Feng, Xiaoming
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supporting information
p. 3470 - 3472
(2013/05/23)
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- Pd(II)-catalyzed oxidative Heck-type reaction of triarylphosphines with alkenes via carbon-phosphorus bond cleavage
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A Pd(II)-catalyzed oxidative Heck-type reaction of triarylphosphines with alkenes via carbon-phosphorus bond cleavage was reported. Under the optimal reaction conditions, most reactions proceeded smoothly to give the expected coupling products in acceptable to high yields.
- Ma, Ming-Tao,Lu, Jian-Mei
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p. 2102 - 2106
(2013/03/13)
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- HETEROCYCLIC COMPOUNDS AND METHODS FOR THEIR USE
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The present invention relates to heterocyclic compounds useful for antagonising angiotensin II Type 2 (AT2) receptor. More particularly the invention relates to pyrrolidine and azetidine compounds, compositions containing them and their use in methods of treating or preventing disorders or diseases associated with AT2 receptor function including neuropathic pain, inflammatory pain, conditions associated with neuronal hypersensitivity, impaired nerve conduction velocity, cell proliferation disorders, disorders associated with an imbalance between bone resorption and bone formation and disorders associated with aberrant nerve regeneration.
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Page/Page column 135
(2013/07/19)
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