- Dramatic Effect of γ-Heteroatom Dienolate Substituents on Counterion Assisted Asymmetric Anionic Amino-Cope Reaction Cascades
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We report a dramatic effect on product outcomes of the lithium ion enabled amino-Cope-like anionic asymmetric cascade when different γ-dienolate heteroatom substituents are employed. For dienolates with azide, thiomethyl, and trifluoromethylthiol substituents, a Mannich/amino-Cope/cyclization cascade ensues to form chiral cyclohexenone products with two new stereocenters in an anti-relationship. For fluoride-substituted nucleophiles, a Mannich/amino-Cope cascade proceeds to afford chiral acyclic products with two new stereocenters in a syn-relationship. Bromide- and chloride-substituted nucleophiles appear to proceed via the same pathway as the fluoride albeit with the added twist of a 3-exo-trig cyclization to yield chiral cyclopropane products with three stereocenters. When this same class of nucleophiles is substituted with a γ-nitro group, the Mannich-initiated cascade is now diverted to a β-lactam product instead of the amino-Cope pathway. These anionic asymmetric cascades are solvent- and counterion-dependent, with a lithium counterion being essential in combination with etheral solvents such as MTBE and CPME. By altering the geometry of the imine double bond from E to Z, the configurations at the R1 and X stereocenters are flipped. Mechanistic, computational, substituent, and counterion studies suggest that these cascades proceed via a common Mannich-product intermediate, which then proceeds via either a chair (X = N3, SMe, or SCF3) or boat-like (X = F, Cl, or Br) transition state to afford amino-Cope-like products or β-lactam in the case of X = NO2.
- Das, Pradipta,Delost, Michael D.,Qureshi, Munaum H.,Bao, Jianhua,Fell, Jason S.,Houk, Kendall N.,Njardarson, Jon T.
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supporting information
p. 5793 - 5804
(2021/05/07)
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- Palladium-Catalyzed Allyl-Allyl Reductive Coupling of Allylamines or Allylic Alcohols with H2as Sole Reductant
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Catalytic carbon-carbon bond formation building on reductive coupling is a powerful method for the preparation of organic compounds. The identification of environmentally benign reductants is key for establishing an efficient reductive coupling reaction. Herein an efficient strategy enabling H2 as the sole reductant for the palladium-catalyzed allyl-allyl reductive coupling reaction is described. A wide range of allylamines and allylic alcohols as well as allylic ethers proceed smoothly to deliver the C-C coupling products under 1 atm of H2. Kinetic studies suggested that the dinuclear palladium species was involved in the catalytic cycle.
- Zhou, Xibing,Zhang, Guoying,Huang, Renbin,Huang, Hanmin
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supporting information
p. 365 - 369
(2021/01/26)
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- Synthesis of Allylsilanes via Nickel-Catalyzed Cross-Coupling of Silicon Nucleophiles with Allyl Alcohols
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NiCl2(PMe3)2-catalyzed reaction of allyl alcohols with silylzinc reagents, including PhMe2SiZnCl, Ph2MeSiZnCl, and Ph3SiZnCl, was performed, achieving allylsilanes in high yields. Aryl- and heteroaryl-substituted allyl alcohols, (E)-3-arylprop-2-en-1-ols, 1-aryl-prop-2-en-1-ols, and (E)-1-phenylpent-1-en-3-ol can be employed in the transformation. A range of functional groups as well as heteroaryl groups were tolerated. Reaction exhibited high regioselectivity and E/Z-selectivity when 1- or 3-aryl-substituted allyl alcohols were used as the substrates. Reaction of chiral allyl alcohol, (S,E)-1-phenylpent-1-en-3-ol, yielded a configuration-inversion product (R,E)-dimethyl(phenyl)(1-phenylpent-1-en-3-yl)silane.
- Yang, Bo,Wang, Zhong-Xia
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supporting information
p. 7965 - 7969
(2019/10/19)
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- Palladium-catalyzed allylic C-H oxidation under simple operation and mild conditions
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We discovered an effective and simple system (Pd/BQ/air/r.t.) for making allylic alcohols through Pd-catalyzed allylic C-H bond functionalization. This approach exhibits advantages due to its simple operation, mild conditions, and environmentally benign features. By modifying reaction conditions, it can be suitable for preparing unsaturated aldehydes, allylic esters, ethers, and amines.
- Guo, Yunlong,Shen, Zengming
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p. 3103 - 3107
(2019/03/26)
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- Copper-Catalyzed Perfluoroalkylation of Allyl Phosphates with Stable Perfluoroalkylzinc Reagents
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A general and practical method for copper-catalyzed cross-coupling of allyl phosphates with stable perfluoroalkylzinc reagents has been developed. The reaction proceeds under mild reaction conditions with high efficiency, good functional group tolerance, and high regio- A nd stereoselectivities and provides general, straightforward, and useful access to allyl-perfluoroalkyl compounds. Preliminary mechanistic studies reveal that the allyl copper intermediate may be involved in the catalytic cycle.
- Liu, Lihua,Bao, Xifei,Xiao, Hua,Li, Junlan,Ye, Feifan,Wang, Chaoqin,Cai, Qinhua,Fan, Shilu
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p. 423 - 434
(2019/01/08)
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- Discovery of novel piperonyl derivatives as diapophytoene desaturase inhibitors for the treatment of methicillin-, vancomycin- and linezolid-resistant Staphylococcus aureus infections
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Inhibition of S. aureus diapophytoene desaturase (CrtN) could serve as an alternative approach for addressing the tricky antibiotic resistance by blocking the biosynthesis of carotenoid pigment which shields the bacterium from host oxidant killing. In this study, we designed and synthesized 44 derivatives with piperonyl scaffold targeting CrtN and the structure-activity relationships (SARs) were examined extensively to bring out the discovery of 21b with potent efficacy and better hERG safety profile compared to the first class CrtN inhibitor benzocycloalkane derivative 2. Except the excellent pigment inhibitory activity against wild-type S. aureus, 21b also showed excellent pigment inhibition against four pigmented MRSA strains. In addition, H2O2 killing and human whole blood killing assays proved 21b could sensitize S. aureus to be killed under oxidative stress conditions. Notably, the murine study in vivo validated the efficacy of 21b against pigmented S. aureus Newman, vancomycin-intermediate S. aureus Mu50 and linezolid-resistant S. aureus NRS271.
- Wei, Hanwen,Mao, Fei,Ni, Shuaishuai,Chen, Feifei,Li, Baoli,Qiu, Xiaoxia,Hu, Linghao,Wang, Manjiong,Zheng, Xinyu,Zhu, Jin,Lan, Lefu,Li, Jian
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p. 235 - 251
(2018/01/17)
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- Palladium-Catalyzed Regioselective Aerobic Allylic C?H Oxygenation: Direct Synthesis of α,β-Unsaturated Aldehydes and Allylic Alcohols
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A protocol for the synthesis of α,β-unsaturated aldehydes and allylic alcohols from simple allylic hydrocarbons with water via palladium-catalyzed functionalization of allylic C?H bonds was described. Molecular oxygen is utilized as the sole oxidant in this oxygenation of terminal alkenes. This protocol features good functional group compatibility, broad substrate scope, and high atom- and step-economy. Moreover, the synthetic utility of this method can be highlighted by its application to the synthesis of ibuprofen, which is a highly potent analgesic. (Figure presented.).
- Li, Chunsheng,Chen, Huoji,Li, Jianxiao,Li, Meng,Liao, Jianhua,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 1600 - 1604
(2018/03/05)
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- Novel Staphyloxanthin Inhibitors with Improved Potency against Multidrug Resistant Staphylococcus aureus
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Diapophytoene desaturase (CrtN) is a potential novel target for intervening in the biosynthesis of the virulence factor staphyloxanthin. In this study, 38 1,4-benzodioxan-derived CrtN inhibitors were designed and synthesized to overwhelm the defects of leading compound 4a. Derivative 47 displayed superior pigment inhibitory activity, better hERG inhibitory properties and water solubility, and significantly sensitized MRSA strains to immune clearance in vitro. Notably, 47 displayed excellent efficacy against pigmented S. aureus Newman, Mu50 (vancomycin-intermediate MRSA, VISA), and NRS271 (linezolid-resistant MRSA, LRSA) comparable to that of linezolid and vancomycin in vivo.
- Ni, Shuaishuai,Li, Baoli,Chen, Feifei,Wei, Hanwen,Mao, Fei,Liu, Yifu,Xu, Yixiang,Qiu, Xiaoxi,Li, Xiaokang,Liu, Wenwen,Hu, Linghao,Ling, Dazheng,Wang, Manjiong,Zheng, Xinyu,Zhu, Jin,Lan, Lefu,Li, Jian
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p. 233 - 237
(2018/03/21)
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- Novel Terminal Bipheny-Based Diapophytoene Desaturases (CrtN) Inhibitors as Anti-MRSA/VISR/LRSA Agents with Reduced hERG Activity
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CrtN has been identified as an attractive and druggable target for treating pigmented Staphylococcus aureus infections. More than 100 new compounds were synthesized, which target the overwhelming the defects of the CrtN inhibitor 1. Analogues 23a and 23b demonstrated a significant activity against pigmented S. aureus Newman and 13 MRSA strains (IC50 = 0.02-10.5 nM), along with lower hERG inhibition (IC50 > 30 μM, ~10-fold decrease in comparison with 1). Furthermore, 23a and 23b were confirmed to reduce the staphylococcal load in the kidney and heart in a mouse model with normal treatment deeper than pretreatment ones, comparable even with vancomycin and linezolid. Remarkably, 23a could strongly block the pigment biosynthesis of these nine multidrug-resistant MRSA strains, including excellent activity against LRSA strains and VISA strains in vivo, and all of which demonstrated that 23a has a huge potential against intractable MRSA, VISA, and LRSA issues as a therapeutic drug.
- Li, Baoli,Ni, Shuaishuai,Mao, Fei,Chen, Feifei,Liu, Yifu,Wei, Hanwen,Chen, Wenhua,Zhu, Jin,Lan, Lefu,Li, Jian
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p. 224 - 250
(2018/02/10)
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- trans-Cyclooctenes as Halolactonization Catalysts
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The strained olefins in trans-cyclooctenes serve as efficient catalysts for halolactonizations, including bromolactonizations and iodolactonizations. The trans-cyclooctene framework is essential for excellent catalytic performance, and the substituents also play important roles in determining efficiency. These results are the first demonstration of catalysis by a trans-cyclooctene.
- Einaru, Shunsuke,Shitamichi, Kenta,Nagano, Tagui,Matsumoto, Akira,Asano, Keisuke,Matsubara, Seijiro
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p. 13863 - 13867
(2018/09/27)
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- Novel Inhibitors of Staphyloxanthin Virulence Factor in Comparison with Linezolid and Vancomycin versus Methicillin-Resistant, Linezolid-Resistant, and Vancomycin-Intermediate Staphylococcus aureus Infections in Vivo
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Our previous work (Wang et al. J. Med. Chem. 2016, 59, 4831-4848) revealed that effective benzocycloalkane-derived staphyloxanthin inhibitors against methicillin-resistant Staphylococcus aureus (S. aureus) infections were accompanied by poor water solubility and high hERG inhibition and dosages (preadministration). In this study, 92 chroman and coumaran derivatives as novel inhibitors have been addressed for overcoming deficiencies above. Derivatives 69 and 105 displayed excellent pigment inhibitory activities and low hERG inhibition, along with improvement of solubility by salt type selection. The broad and significantly potent antibacterial spectra of 69 and 105 were displayed first with normal administration in the livers and hearts in mice against pigmented S. aureus Newman, Mu50 (vancomycin-intermediate S. aureus), and NRS271 (linezolid-resistant S. aureus), compared with linezolid and vancomycin. In summary, both 69 and 105 have the potential to be developed as good antibacterial candidates targeting virulence factors.
- Ni, Shuaishuai,Wei, Hanwen,Li, Baoli,Chen, Feifei,Liu, Yifu,Chen, Wenhua,Xu, Yixiang,Qiu, Xiaoxia,Li, Xiaokang,Lu, Yanli,Liu, Wenwen,Hu, Linhao,Lin, Dazheng,Wang, Manjiong,Zheng, Xinyu,Mao, Fei,Zhu, Jin,Lan, Lefu,Li, Jian
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supporting information
p. 8145 - 8159
(2017/10/18)
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- Silver-catalyzed Meerwein arylation: Intermolecular and intramolecular fluoroarylation of styrenes
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The first example of silver-catalyzed intermolecular and intramolecular Meerwein fluoroarylation of styrenes with aryl diazonium salts has been developed. This reaction is operationally simple, scalable and proceeds under mild conditions. Furthermore, fluorinated dihydrobenzofurans and indolines were easily accessed using this method. This journal is
- Guo, Rui,Yang, Haodong,Tang, Pingping
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p. 8829 - 8832
(2015/05/20)
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- Design, synthesis and biological evaluation of B-region modified diarylalkyl amide analogues as novel TRPV1 antagonists
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Design, synthesis and biological evaluation of B-region, known to be a dipolar interacting pharmacophore, modified diarylalkyl amide analogues for novel TRPV1 (transient receptor potential channel, vanilloid subfamily member 1) antagonists was described. A variety of moieties including guanidines, heterocyclic rings, cinnamides, and α-substituted acetamides were introduced at the B-region. TRPV1 antagonistic activities of these analogues were evaluated by 45Ca2+ uptake assay in rat DRG neuron. In particular, α,α-difluoroamide 53 exhibited 3-fold more potent TRPV1 antagonistic activity (IC50 = 0.058 μM) than the parent amide analogue 6.
- Han, Young Taek,Yang, Shao-Mei,Wang, Xiao-Yuan,Li, Fu-Nan
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p. 440 - 451
(2014/04/17)
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- NOVEL COMPOUNDS, ISOMER THEREOF OR PHARMACEUTICALLY ACCEPTABLE SALTS THEREOF AS VANILLOID RECEPTOR ANTAGONIST; AND A PHARMACEUTICAL COMPOSITION CONTAINING THE SAME
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This present invention relates to novel compounds, isomer thereof or pharmaceutically acceptable salts thereof as vanilloid receptor (Vanilloid Receptor 1; VR1; TRPV1 )antagonist; and a pharmaceutical composition containing the same. The present invention
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Page/Page column 54-55
(2010/11/23)
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- Discovery of potent, orally available vanilloid receptor-1 antagonists. Structure-activity relationship of N-aryl cinnamides
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The vanilloid receptor-1 (TRPV1 or VR1) is a member of the transient receptor potential (TRP) family of ion channels and plays a role in regulating the function of sensory nerves. A growing body of evidence demonstrates the therapeutic potential of TRPV1 modulators, particularly in the management of pain. As a result of our screening efforts, we identified (E)-3-(4-tert- butylphenyl)-N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)acrylamide (1), an antagonist that blocks the capsaicin-induced and pH-induced uptake of 45Ca2+ in TRPV1-expressing Chinese hamster ovary cells with IC50 values of 17 ± 5 and 150 ± 80 nM, respectively. In this report, we describe the synthesis and structure-activity relationship of a series of N-aryl cinnamides, the most potent of which (49a and 49b) exhibit good oral bioavailability in rats (Foral = 39% and 17%, respectively).
- Doherty, Elizabeth M.,Fotsch, Christopher,Bo, Yunxin,Chakrabarti, Partha P.,Chen, Ning,Gavva, Narender,Han, Nianhe,Kelly, Michael G.,Kincaid, John,Klionsky, Lana,Liu, Qingyian,Ognyanov, Vassil I.,Tamir, Rami,Wang, Xianghong,Zhu, Jiawang,Norman, Mark H.,Treanor, James J. S.
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- Kinetic resolution of acyclic secondary allylic silyl ethers catalyzed by chiral ketones
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Kinetic resolution of acyclic secondary allylic silyl ethers by chiral dioxiranes generated in situ from chiral ketones (R)-1 and (R)-2 and Oxone was investigated. An efficient and catalytic method has been developed for kinetic resolution of those substrates with a CCl3, tert-butyl, or CF3 group at the α-position. In particular, high selectivities (S up to 100) were observed for kinetic resolutions of racemic α-trichloromethyl allylic silyl ethers 7 and 9-15 catalyzed by ketones (R)-2. Both the recovered substrates and the resulting epoxides were obtained in high enantiomeric excess. On the basis of steric and electrostatic interactions between the chiral dioxiranes and the racemic substrates, a model was proposed to rationalize the enantioselectivities and diastereoselectivities in the chiral ketone-catalyzed kinetic resolution process.
- Yang,Jiao,Yip,Lai,Wong
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p. 4619 - 4624
(2007/10/03)
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- Rational design of Mn-salen epoxidation catalysts: Preliminary results
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(Salen)manganese(III) complex 7 designed on the basis of the new proposal on the olefin's access to metal-oxo bond and complex 10 having axial chirality in salicylaldehyde part were found to be effective catalysts for the epoxidation of unfunctionalized olefins, especially for cis-olefins.
- Hosoya, Naoki,Hatayama, Akira,Irie, Ryo,Sasaki, Hidehiko,Katsuki, Tsutomu
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p. 4311 - 4322
(2007/10/02)
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