- Iron-Catalyzed ?±,?-Dehydrogenation of Carbonyl Compounds
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An iron-catalyzed α,β-dehydrogenation of carbonyl compounds was developed. A broad spectrum of carbonyls or analogues, such as aldehyde, ketone, lactone, lactam, amine, and alcohol, could be converted to their α,β-unsaturated counterparts in a simple one-step reaction with high yields.
- Zhang, Xiao-Wei,Jiang, Guo-Qing,Lei, Shu-Hui,Shan, Xiang-Huan,Qu, Jian-Ping,Kang, Yan-Biao
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supporting information
p. 1611 - 1615
(2021/03/03)
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- Piperlongumine derivative as well as preparation method and application thereof
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The invention discloses a Piperlongumine derivative as well as a preparation method and application thereof. The Piperlongumine derivative has the following structure: the Piperlongumine derivative provided by the invention contains a plurality of Michael addition receptor units, and the novel structure improves the electrophilicity, so that the Piperlongumine derivative has good protein targetingpotential, and the Piperlongumine derivative has a good inhibition effect on thioredoxin reductase; in an antitumor bioactive in-vitro screening experiment, the derivative also has a certain inhibition effect on the growth of tumor cells, and meanwhile, the derivative has an effect of promoting the generation of active oxygen in A549 human lung cancer cells.
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Paragraph 0033; 0041-0043; 0094-0097
(2021/01/28)
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- Stereodivergent Pd/Cu Catalysis for the Dynamic Kinetic Asymmetric Transformation of Racemic Unsymmetrical 1,3-Disubstituted Allyl Acetates
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A stereodivergent Pd/Cu catalyst system has been developed for the unprecedented dynamic kinetic asymmetric transformation (DyKAT) of racemic unsymmetrical 1,3-disubstituted allylic acetates with prochiral aldimine esters. A series of α,α-disubstituted α-amino acids bearing vicinal stereocenters were easily prepared with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to >20:1 dr). Moreover, all four stereoisomers of the product can be readily obtained simply by switching the configurations of the two chiral metal catalysts. Furthermore, the present work highlights the power of synergistic Pd/Cu catalysis consisting of two common bidentate chiral ligands for stereodivergent synthesis.
- He, Rui,Huo, Xiaohong,Zhao, Ling,Wang, Feijun,Jiang, Liyin,Liao, Jian,Zhang, Wanbin
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supporting information
p. 8097 - 8103
(2020/05/22)
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- Sequential Two-Step Stereoselective Amination of Allylic Alcohols through the Combination of Laccases and Amine Transaminases
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A sequential two-step chemoenzymatic methodology for the stereoselective synthesis of (3E)-4-(het)arylbut-3-en-2-amines in a highly selective manner and under mild reaction conditions is described. The approach consists of oxidation of the corresponding racemic alcohol precursors by the use of a catalytic system made up of the laccase from Trametes versicolor and the oxy-radical TEMPO, followed by the asymmetric reductive bio-transamination of the corresponding ketone intermediates. Optimisation of the oxidation reaction, exhaustive amine transaminase screening for the bio-transaminations and the compatibility of the two enzymatic reactions were studied in depth in search of a design of a compatible sequential cascade. This synthetic strategy was successful and the combinations of enzymes displayed a broad substrate scope, with 16 chiral amines being obtained in moderate to good isolated yields (29–75 %) and with excellent enantiomeric excess values (94 to >99 %). Interestingly, both amine enantiomers can be achieved, depending on the selectivity of the amine transaminase employed in the system.
- Albarrán-Velo, Jesús,Lavandera, Iván,Gotor-Fernández, Vicente
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p. 200 - 211
(2019/12/03)
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- One-pot two-step chemoenzymatic deracemization of allylic alcohols using laccases and alcohol dehydrogenases
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A series of enantioenriched (hetero)aromatic secondary allylic alcohols has been synthesized through deracemization of the corresponding racemic mixtures combining a non-selective chemoenzymatic oxidation (laccase from Trametes versicolor and oxy-radical TEMPO) and a stereoselective biocatalyzed reduction (lyophilized cells of E. coli overexpressing an alcohol dehydrogenase, ADH). Both steps were performed in aqueous medium under very mild reaction conditions. After optimization, a sequential one-pot two-step protocol was set up, obtaining the corresponding chiral alcohols in moderate to high conversions (48–95%) and enantiomeric excess (65->99% ee). Depending on the ADH stereopreference, both antipodes from these valuable chiral synthons could be prepared, even at preparative scale (119?178 mg), in a straightforward manner.
- Albarrán-Velo, Jesús,Gotor-Fernández, Vicente,Lavandera, Iván
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- RhIII-Catalyzed Synthesis of Highly Substituted 2-Pyridones using Fluorinated Diazomalonate
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A RhIII-catalyzed strategy was developed for the rapid construction of highly substituted 2-pyridone scaffolds using α,β-unsaturated oximes and fluorinated diazomalonate. The reaction proceeds through direct, site-selective alkylation based on migratory insertion and subsequent cyclocondensation. A wide substrate scope with different functional groups was explored. The requirement of fluorinated diazomalonate was explored for this transformation. The developed methodology was further extended with the synthesis of the bioactive compound.
- Das, Debapratim,Sahoo, Gopal,Biswas, Aniruddha,Samanta, Rajarshi
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supporting information
p. 360 - 364
(2020/01/25)
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- Selective Cross-Dehydrogenative C(sp3)-H Arylation with Arenes
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Selective C(sp3)-C(sp2) bond construction is of central interest in chemical synthesis. Despite the success of classic cross-coupling reactions, the cross-dehydrogenative coupling between inert C(sp3)-H and C(sp2)-H bonds represents an attractive alternative toward new C(sp3)-C(sp2) bonds. Herein, we establish a selective inter-and intramolecular C(sp3)-H arylation of alcohols with nondirected arenes that thereby provides a general pathway to access a wide range of β-arylated alcohols, including tetrahydronaphthalen-2-ols and benzopyran-3-ols, with high to excellent chemo-and regioselectivity.
- Hao, Hong-Yan,Mao, Yang-Jie,Xu, Zhen-Yuan,Lou, Shao-Jie,Xu, Dan-Qian
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supporting information
p. 2396 - 2402
(2020/03/13)
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- Catalytic Enantioselective Conjugate Addition of Stereodefined Di- and Trisubstituted Alkenylaluminum Compounds to Acyclic Enones
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Catalytic enantioselective conjugate addition (ECA) reactions with readily accessible and stereochemically defined E-, Z-, di- and trisubstituted alkenyl aluminum compounds are disclosed. Transformations are promoted by various NHC-copper catalysts (NHC=N-heterocyclic carbene), which are derived from enantiomerically pure sulfonate imidazolinium salts. The desired products were obtained in up to 89% yield and >99:1 e.r.; the alkenyl moiety was transferred with complete retention of its stereochemical identity in all instances. The scope and limitations of the approach, key mechanistic attributes, and representative functionalization are presented as well. (Figure presented.).
- McGrath, Kevin P.,Hubbell, Aran K.,Zhou, Yuebiao,Santos, Damián Padín,Torker, Sebastian,Romiti, Filippo,Hoveyda, Amir H.
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supporting information
p. 370 - 375
(2019/12/24)
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- An access to α, β-unsaturated ketones via dual cooperative catalysis
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A dual cooperative organocatalytic approach for the synthesis of α, β-unsaturated ketones is described. This one pot transformation is realized via a domino Knoevenagel-Michael-retro Michael reaction sequence. Various aliphatic ketones reacted smoothly with aromatic as well as aliphatic aldehydes in presence catalytic amount of Meldrum's acid and bifunctional amine. The highlights of this protocol are the easy availability of catalysts, high selectivity, and functional group tolerance. The reaction proved to highly E-selective with no side products emanating from self-condensation, unlike the base-mediated reactions.
- Syamala, Lakshmi V.R. Babu,Khopade, Tushar M.,Warghude, Prakash K.,Bhat, Ramakrishna G.
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supporting information
p. 88 - 91
(2018/12/05)
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- Dehydrozingerone Inspired Discovery of Potential Broad-Spectrum Fungicidal Agents as Ergosterol Biosynthesis Inhibitors
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A series of dehydrozingerone derivatives were synthesized, and their fungicidal activities and action mechanism against Colletotrichum musae were evaluated. The bioassay result showed that most compounds exhibited excellent fungicidal activity in vitro at 50 μg mL-1. Compounds 13, 16, 18, 19, and 27 exhibited broad-spectrum fungicidal activity; especially, compounds 19 and 27 were found to have more potent fungicidal activity than azoxystrobin. The EC50 values of compounds 19 and 27 against Rhizoctonia solani were 0.943 and 0.161 μg mL-1 respectively. Moreover, compound 27 exhibited significant in vitro bactericidal activity against Xanthomonas oryzae pv. oryzae, with an EC50 value of 11.386 μg mL-1, and its curative effect (49.64%) and protection effect (51.74%) on rice bacterial blight disease was equivalent to that of zhongshengmycin (42.90%, 40.80% respectively). Compound 27 could also effectively control gray mold (87.10%, 200 μg mL-1) and rice sheath blight (100%, 200 μg mL-1 82.89%, 100 μg mL-1) in vivo. Preliminary action mechanism study showed that compound 27 mainly acted on the cell membrane and significantly inhibited ergosterol biosynthesis in Colletotrichum musae.
- Song, Xiangmin,Zhu, Xinyue,Li, Ting,Liang, Cai,Zhang, Meng,Shao, Yu,Tao, Jun,Sun, Ranfeng
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p. 11354 - 11363
(2019/10/16)
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- Dehydrozingerone derivative and preparation method and application thereof
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The invention provides a dehydrozingerone derivative as shown in the description. R-R are each independently selected from hydrogen or halogen or a nitro group or an alkyl group or a substitutedalkoxy group or an alkoxy group or a hydroxyl group; the substituent in the substituted alkoxy group is selected from one or multiple of halogen, a nitro group and a hydroxyl group; R and R areeach independently selected from hydrogen or halogen or nitrogen-containing heterocycle; R is selected from an alkyl group or an alkoxy group or a substituted alkoxy group; the substituent in thesubstituted alkyl group is selected from one or multiple of halogen, a nitro group and a hydroxyl group; X is selected from a hetero atom or a hydroxylamine group. The dehydrozingerone derivative hasbroad-spectrum activity against plant pathogenic fungi and bacteria, and has certain nematicidal activity, and is a lead compound with the broad biological activity.
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Paragraph 0084-0087; 0088; 0089
(2019/11/20)
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- Synthesis of Enones and Enals via Dehydrogenation of Saturated Ketones and Aldehydes
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A general, efficient and economic palladium-catalyzed dehydrogenation to form enones or enals has been developed. The approach possesses extremely broad substrate scope including various linear or cyclic saturated ketones and aldehydes. The protocol is ligand-free, and molecular oxygen is used as the sole clean oxidant in the reaction. Due to mild reaction conditions, good functional group compatibility, and versatile utilities of enones and enals, the method can be applied in the late-stage synthesis of natural products, pharmaceuticals and fine chemicals. (Figure presented.).
- Pan, Gao-Fei,Zhu, Xue-Qing,Guo, Rui-Li,Gao, Ya-Ru,Wang, Yong-Qiang
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p. 4774 - 4783
(2018/11/10)
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- Natural product-based pesticide discovery: Design, synthesis and bioactivity studies of N-amino-maleimide derivatives
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Natural products are an important source of pesticide discovery. A series of N-amino-maleimide derivatives containing hydrazone group were designed and synthesized based on the structure of linderone and methyllinderone which were isolated from Lindera erythrocarpa Makino. According to the bioassay results, compounds 2 and 3 showed 60% inhibition against mosquito (Culex pipiens pallens) at 0.25 μg·mL?1. Furthermore, the results of antifungal tests indicated that most compounds exhibited much better antifungal activities against fourteen phytopathogenic fungi than linderone and methyllinderone and some compounds exhibited better antifungal activities than commercial fungicides (carbendazim and chlorothalonil) at 50 μg·mL?1. In particular, compound 12 exhibited broad-spectrum fungicidal activity (>50% inhibitory activities against 11 phytopathogenic fungi) and compounds 12 and 14 displayed 60.6% and 47.9% inhibitory activity against Rhizoctonia cerealis at 12.5 μg·mL?1 respectively. Furthermore, compound 17 was synthesized, which lacks N-substituent at maleimide and its poor antifungal activity against Sclerotinia sclerotiorum and Rhizoctonia cerealis at 50 μg·mL?1 showed that the backbone structure of N-amino-maleimide derivatives containing hydrazone group was important to the antifungal activity.
- Song, Xiangmin,Liu, Chunjuan,Chen, Peiqi,Zhang, Hao,Sun, Ranfeng
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- Rh(III)-Catalyzed Enaminone-Directed Alkenyl C-H Activation for the Synthesis of Salicylaldehydes
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A Rh(III)-catalyzed enaminone-directed alkenyl C-H coupling with alkynes for the synthesis of salicylaldehyde derivatives is reported. This represents a unique example of benzene ring framework formation through a transition-metal-catalyzed, directed C-H activation strategy. The two incorporated reactive functionalities, aldehyde and hydroxy groups, provide convenient synthetic handles for further structural elaboration.
- Qi, Bing,Guo, Shan,Zhang, Wenjing,Yu, Xiaolong,Song, Chao,Zhu, Jin
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supporting information
p. 3996 - 3999
(2018/07/15)
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- Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: Chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles
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A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions.
- Zhang, Song-Lin,Deng, Zhu-Qin
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p. 7282 - 7294
(2016/08/05)
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- Synthesis of Polysubstituted Pyridines via a One-Pot Metal-Free Strategy
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An efficient strategy for the one-pot synthesis of polysubstituted pyridines via a cascade reaction from aldehydes, phosphorus ylides, and propargyl azide is reported. The reaction sequence involves a Wittig reaction, a Staudinger reaction, an aza-Wittig reaction, a 6π-3-azatriene electrocyclization, and a 1,3-H shift. This protocol provides quick access to the polysubstituted pyridines from readily available substrates in good to excellent yields.
- Wei, Hongbo,Li, Yun,Xiao, Ke,Cheng, Bin,Wang, Huifei,Hu, Lin,Zhai, Hongbin
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supporting information
p. 5974 - 5977
(2016/01/09)
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- Steric and Electronic Requirements in the Synthesis of 2,3-Dihydro-4(1H)-quinolinones by the Tandem Michael-SNAr Reaction
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The steric and electronic requirements have been investigated for the synthesis of 2,3-dihydro-4(1H)-quinolinones by the tandem Michael-SNAr reaction. Substrates bearing a single methyl group at the β-enone carbon gave excellent yields of the title compounds from both the E and Z isomers with X=H or NO2. Substrates with β,β-dimethyl substitution at the Michael terminus gave low yields of heterocyclic products in molecules having monoactivated SNAr aromatic acceptor rings (X=H) and very good yields for diactivated systems (X=NO2). For these hindered substrates, success in the final cyclization hinges on the ability of the aromatic acceptor to capture the pendant nitrogen nucleophile of the initial Michael adduct before this intermediate can revert to starting materials.
- Bunce, Richard A.,Nago, Takahiro,Abuskhuna, Suaad
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p. 1143 - 1149
(2015/08/06)
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- Design, synthesis and biological evaluation of novel C3-functionalized oxindoles as potential Pim-1 kinase inhibitors
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A novel series of C3-functionalized oxindoles, 3-(2-oxo-4-phenylbut-3-en-1-ylidene)indolin-2-ones, were designed, synthesized and investigated for inhibition of cell proliferation against different types of human cancer cell lines, including SW620, HeLa and A549. This biological study showed that these compounds containing the scaffolds of indole and aromatic α,β-unsaturated ketone had moderate to significant antitumor activities. Further study suggested that compound 4b, as one of this kind of structure derivative, showed broad-spectrum antitumor activities against MCF-7, PC-3, SKOV-3, U87, SMMC-7721, SY5Y and A875 cancer cell lines. Besides, the results of the inhibition of Pim kinases indicated that compound 4b showed selective and efficient anti-Pim-1 kinase activity (IC50 = 5 μM). Docking simulation, flow cytometry (FCM), and Hoechst 33342 staining assay suggested that the most active compound 4b induced cell death through apoptosis via binding to the active ATP pocket of Pim-1. Moreover, it showed that compound 4b had strong inhibition of tubulin polymerization which may be caused by inhibiting Pim-1. This journal is
- Sun, Hong-Bao,Wang, Xiao-Yan,Li, Guo-Bo,Zhang, Li-Dan,Liu, Jie,Zhao, Li-Feng
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p. 29456 - 29466
(2015/04/14)
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- Palladium-catalyzed conjugate addition of arylsulfonyl hydrazides to α,β-unsaturated ketones
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A palladium-catalyzed desulfitative-denitrogenative conjugate addition of arylsulfonyl hydrazides to α,β-unsaturated ketones is described. The reaction showed very good selectivity and tolerated a wide range of functionalities under an atmosphere of oxygen with or without the aid of a metal co-oxidant. The Royal Society of Chemistry 2013.
- Chen, Wen,Chen, Hui,Xiao, Fuhong,Deng, Guo-Jun
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supporting information
p. 4295 - 4298
(2013/08/23)
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- Cyclohexane 1,3-diones and their inhibition of mutant SOD1-dependent protein aggregation and toxicity in PC12 cells
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Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons. Currently, there is only one FDA-approved treatment for ALS (riluzole), and that drug only extends life, on average, by 2-3 months. Mutations in Cu/Zn superoxide dismutase (SOD1) are found in familial forms of the disease and have played an important role in the study of ALS pathophysiology. On the basis of their activity in a PC12-G93A-YFP high-throughput screening assay, several bioactive compounds have been identified and classified as cyclohexane-1,3-dione (CHD) derivatives. A concise and efficient synthetic route has been developed to provide diverse CHD analogs. The structural modification of the CHD scaffold led to the discovery of a more potent analog (26) with an EC50 of 700 nM having good pharmacokinetic properties, such as high solubility, low human and mouse metabolic potential, and relatively good plasma stability. It was also found to efficiently penetrate the blood-brain barrier. However, compound 26 did not exhibit any significant life span extension in the ALS mouse model. It was found that, although 26 was active in PC12 cells, it had poor activity in other cell types, including primary cortical neurons, indicating that it can penetrate into the brain, but is not active in neuronal cells, potentially due to poor selective cell penetration. Further structural modification of the CHD scaffold was aimed at improving global cell activity as well as maintaining potency. Two new analogs (71 and 73) were synthesized, which had significantly enhanced cortical neuronal cell permeability, as well as similar potency to that of 26 in the PC12-G93A assay. These CHD analogs are being investigated further as novel therapeutic candidates for ALS.
- Zhang, Wei,Benmohamed, Radhia,Arvanites, Anthony C.,Morimoto, Richard I.,Ferrante, Robert J.,Kirsch, Donald R.,Silverman, Richard B.
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experimental part
p. 1029 - 1045
(2012/03/09)
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- QUINAZOLIN-OXIME DERIVATIVES AS HSP90 INHIBITORS
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Compounds of general formula (I); or a stereoisomers, tautomers, pharmaceutically acceptable salts, or prodrugs thereof, wherein R1, R2, R3, R4, R5, R6, R8 and R9 are as defined herein, are useful for the treatment of diseases and conditions which are mediated by excessive or inappropriate Hsp90 activity such as cancers, viral infection and inflammatory diseases or conditions.
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Page/Page column 11
(2011/06/10)
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- HETEROCYCLIC COMPOUNDS USEFUL AS ANABOLIC AGENTS FOR LIVESTOCK ANIMALS
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Compounds of formula (I) and pharmaceutically acceptable salts thereof are agonists at the beta-2 adrenoceptor. They are useful as feed additives for livestock animals.
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Page/Page column 82
(2008/06/13)
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- The effect of acid-base pairing on catalysis: An efficient acid-base functionalized catalyst for aldol condensation
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Acid-base bifunctionalized heterogeneous catalysts may be capable of exhibiting reactivity not achievable with homogeneous catalysts. We investigated the effect of pKa of the acid component of mesoporous solids containing acid-base bifunctionality on their catalytic ability toward aldol condensation between 4-nitrobenzaldehyde and acetone. We found that higher levels of aldol product conversion were obtained when weaker acid components (phosphoric, carboxylic vs sulfonic) were used, an indication of the importance of the equilibrium between free acid and free base and the resulting neutralized ion pair in the catalytic capability of acid-base functionalized materials. A catalyst containing primary amine groups in combination with carboxylic acid groups (with similar chemical functionalities to proline) was found to be a superior catalyst in this aldol reaction with a number of different electrophilic components.
- Zeidan, Ryan K.,Davis, Mark E.
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p. 379 - 382
(2008/03/12)
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- A catalytic, highly stereoselective aldehyde olefination reaction
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A catalytic aldehyde olefination reaction has been discovered. A Cu(II) complex (5 mol %) derived from a salen-quinine mixed ligand catalyzed the reaction between aldehydes and two molecules of acetyl chloride to produce trans C-C double bonds exclusively. The new catalytic aldehyde alkenation reaction presumably goes through a C-3 acylated β-lactone intermediate that loses one molecule of CO2.
- Lin, Yun-Ming,Li, Zhongtao,Casarotto, Virginie,Ehrmantraut, Jessica,Nguyen, Annie N.
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p. 5531 - 5534
(2008/02/13)
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