- Identification and optimization of piperine analogues as neuroprotective agents for the treatment of Parkinson's disease via the activation of Nrf2/keap1 pathway
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Parkinson's disease (PD) is a slowly progressive and complex neurodegenerative disorder. Up to date, there are no approved drugs that could slow or reverse the neurodegenerative process of PD. Here, we reported the synthesis of series of piperine analogues and the evaluation of their neuroprotective effects against hydrogen peroxide (H2O2) induced damage in the neuron-like PC12 cells. Among these analogues, 3b exhibited the most potent protection effect and its underlying mechanism was further investigated. Further results indicated that the ROS scavenging and cytoprotection effect of 3b might be related to the Nrf2 activation and upregulation of related phase II antioxidant enzymes, such as HO-1 and NQO1. In in vivo study, oral administration (100 mg/kg) of 3b significantly attenuated PD-associated behavioral deficits in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD and protected tyrosine hydroxylase-immunopositive dopaminergic neurons. Our results provided evidence that 3b might be a promising candidate for Parkinson's disease treatment.
- Cai, Xiaoying,Chen, Lijuan,Hong, Feng,Kuang, Shuang,Li, Yan,Ma, Xu,Qi, Wenyan,Shi, Mingsong,Wang, Lun,Xu, Ruiling,Xue, Linlin,Ye, Haoyu,Zhang, Ruijia
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- Borane-Catalyzed Reductive α-Silylation of Conjugated Esters and Amides Leaving Carbonyl Groups Intact
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Described herein is the development of the B(C6F5)3-catalyzed hydrosilylation of α,β-unsaturated esters and amides to afford synthetically valuable α-silyl carbonyl products. The α-silylation occurs chemoselectively, thus leaving the labile carbonyl groups intact. The reaction features a broad scope of both acyclic and cyclic substrates, and the synthetic utility of the obtained α-silyl carbonyl products is also demonstrated. Mechanistic studies revealed two operative steps: fast 1,4-hydrosilylation of conjugated carbonyls and then slow silyl group migration of a silyl ether intermediate.
- Kim, Youngchan,Chang, Sukbok
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supporting information
p. 218 - 222
(2016/01/25)
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- RhIII-catalyzed oxidative olefination of vinylic C-H bonds: Efficient and selective access to Di-unsaturated α-amino acid derivatives and other linear 1,3-butadienes
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Olefin(s) get-together! A RhIII-catalyzed oxidative cross-coupling of different olefins was developed, resulting in the formation of valuable linear butadiene products and especially di-unsaturated α-amino acid derivatives. 1,1-Di-, 1,2-di-, and 1,1,2-trisubstituted olefins could be coupled with styrenes and acrylates. In these reactions, remarkably high levels of chemo-, regio-, and stereoselectivity were obtained, rendering this a valuable synthetic tool. Copyright
- Besset, Tatiana,Kuhl, Nadine,Patureau, Frederic W.,Glorius, Frank
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supporting information; experimental part
p. 7167 - 7171
(2011/07/31)
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- Synthesis of 2-, 4- And 5-(2-alkylcarbamoyl-l-methylvinyl)-7- alkyloxybenzo[b]furans and their leukotriene 64 receptor antagonistic activity
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Variable benzo[6]furan derivatives having (E)- and (Z)-2-alkylcarbamoyl-l- methylvinyl groups at the 2-, 4- and 5-positions and a carboxylpropoxy or (1-phenyl)ethoxy group at the 7-position were prepared to find novel and selective leukotriene B4 (LTB4) receptor antagonists. (E)-2-(2-Diethylcarbamoyl- l-methylvinyl)-7-(1-phenylethoxy)benzo[b]furan (4v) showed selective inhibition to the human BLT2 receptor (hBLT2). On the other hand, (E)-2-acetyl-4-(2-diethylcarbamoyl-l-methylvinyl)-7-(l-phenylethoxy)benzo[b] furan (7v) inhibited both human BLTi receptor (hBLT1) and hBLT 2. The (E)-2-(2-diethylcarbamoyl-l-methylvinyl) group lay on approximately the same plane as the benzo[e]furan ring, whereas the (E)-4-(2-diethylcarbamoyl-l-methylvinyl) group had the torsion angle (45.7°) from the benzo[e]furan ring plane. However, the (Z)-(2-alkylcarbamoyl-l- methylvinyl)benzo[b]furans were inactive. The inhibitory activity depended on the conformation of the 2-diethylcarbamoyl-l-methylvinyl group. The Royal Society of Chemistry 2005.
- Ando, Kumiko,Tsuji, Eriko,Ando, Yuko,Kunitomo, Jun-Ichi,Kobayashi, Reina,Yokomizo, Takehiko,Shimizu, Takao,Yamashita, Masayuki,Ohta, Shunsaku,Nabe, Takeshi,Kohno, Shigekatsu,Ohishi, Yoshitaka
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p. 2129 - 2139
(2007/10/03)
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- Syntheses of 3-acetoacetylaminobenzo[b]furan derivatives having cysteinyl leukotriene 2 receptor antagonistic activity
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Novel 3-acetoacetylaminobenzo[b]furan derivatives having a modified triene system at the 3-position were synthesized starting with 3-aminobenzo[b]furans. The enol isomers, 3-[(3-hydroxybul-2-enonyl)amino]benzo[b]furans (1), of the 3-acetoacetylaminobenzo[b]furans were obtained as stable isomers owing to formation of a hydrogen bonding between the enol hydroxyl group and the amidocarbonyl group. The planarity of the C-2 substituent through the C-3 side chain suggested the existence of a modified conjugational triene system in the enol compound. Cysteinyl leukotriene 1 and 2 receptor antagonistic activities for these compounds were evaluated. 2-(4-Cyanobenzoyl or ethoxycarbonyl)-3-[(2-cyano-3-hydroxybut-2-enonyl)amino]benzo[e]furans (15g, 15o, 15u) were moderately active.
- Ando, Kumiko,Tsuji, Eriko,Ando, Yuko,Kuwata, Noriko,Kunitomo, Jun-Ichi,Yamashita, Masayuki,Ohta, Shunsaku,Kohno, Shigekatsu,Ohishi, Yoshitaka
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p. 625 - 635
(2007/10/03)
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- Unusual Regioselectivity of the Dipolar Cycloaddition Reactions of Nitrile Oxides and Tertiary Cinnamides and Crotonamides
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Benzonitrile oxides undergo 1,3-dipolar cycloaddition reactions with methyl cinnamate to produce the 5-phenyl and 4-phenyl regioisomers in approximately an 80:20 ratio. However, use of N,N-diethylcinnamide as the dipolarophile unexpectedly resulted in the formation of the 5-phenyl and 4-phenyl regioisomers in a 23:77 ratio. Studies have shown that this phenomena occurs only for tertiary cinnamides. In addition, it has been demonstrated that the phenyl group of tertiary cinnamides is not essential for the reversal of regioselectivity since crotonamides produce the same results and trends as the cinnamides. However, since acrylates and acrylamides both produce the 5-carbonyl regioisomers, it can be concluded that the β-substituent is playing a key role for the unexpected results by possibly increasing steric interactions between the dipole and dipolarophile in the transition state. Transition state energies were calculated for the regioisomeric cycloadduct pairs derived from several crotonamides as well as methyl crotonate. These calculations indicate that steric factors are indeed responsible for the reversal of regioselectivity.
- Weidner-Wells, Michele A.,Fraga-Spano, Stephanie A.,Turchi, Ignatius J.
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p. 6319 - 6328
(2007/10/03)
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- Tandem conjugate addition-aldol reaction to α,β-unsaturated esters and ketones using titanium amide
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Titanium dialkylamide, readily available, adds to a α,β-unsaturated esters and ketones in a conjugate addition mode to give ester and ketone enolates, respectively, which are successively quenched with electrophiles such as aldehydes and acetals. The aldol products can be readily converted to the corresponding deaminated or dehydrated derivatives selectively.
- Hosomi, Akira,Yanagi, Toshiharu,Hojo, Makoto
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p. 2371 - 2374
(2007/10/02)
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- Palladium-Catalyzed Double-Carbonylation of Alkenyl Halides with Secondary Amines to Give α-Keto Amides
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The double-carbonylation reaction of alkenyl halides with diethylamine in the presence of palladium catalysts has been examined in detail.The reaction gives α-keto amide together with amide, the single carbonylation by-product.The yield of α-keto amide is strongly dependent on the nature of alkenyl halide.Alkenyl bromides or iodides having phenyl group(s) as substituent(s) on the vinyl group are successfully double-carbonylated under appropriate reaction conditions and the corresponding α-keto amides are obtained in good to modest yields together with amides.In contrast, the reactions of alkenyl halides without a phenyl group give amides exclusively.In order to clarify the reason for the substrate-specificity in the reaction, series of alkenyl- and alkenoylpalladium(II) complexes, the presumed intermediates in the catalytic reactions, have been prepared and their reactions with secondary amines, carbon monoxide, and alkenyl halides were examined.The study suggests the operation of three types of processes for amide formation in the catalytic reactions.Possible mechanism for amide as well as α-keto amide formation are discussed.
- Son, Tae-il,Yanagihara, Hisayoshi,Ozawa, Fumiyuki,Yamamoto, Akio
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p. 1251 - 1258
(2007/10/02)
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- SYNTHESE REGIOSPECIFIQUE D'AMIDO-1 VINYL-2 CYCLOPROPANES A PARTIR DE LITHIENS ALLYLIQUES MONOHALOGENES ET D'AMIDES TERTIAIRES α-ETHYLENIQUIES
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Chloroallyllitium and gem-chloro(methyl)allyllithium readly react, via conjugated addition and cyclisation, with α-ethylenic aliphatic tertiary amides to produce, in a "one-pot" reaction, alkyl-substituted 1-amido-2-vinylcyclopropanes.
- Ongoka, Pascal,Mauze, Bernard,Miginiac, Leone
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p. 131 - 140
(2007/10/02)
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