- (E)-Alkenes as replacements of amide bonds: Development of novel and potent acyclic CGRP receptor antagonists
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A new class of CGRP receptor antagonists was identified by replacing the central amide of a previously identified anilide lead structure with ethylene, ethane, or ethyne linkers. (E)-Alkenes as well as alkynes were found to preserve the proper bioactive conformation of the amides, necessary for efficient receptor binding. Further exploration resulted in several potent compounds against CGRP-R with low susceptibility to P-gp mediated efflux.
- Kim, June J.,Wood, Michael R.,Stachel, Shawn J.,De Leon, Pablo,Nomland, Ashley,Stump, Craig A.,McWherter, Melody A.,Schirripa, Kathy M.,Moore, Eric L.,Salvatore, Christopher A.,Selnick, Harold G.
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- ASYMMETRIC 3-AZA-COPE REARRANGEMENTS USING TiCl4 CATALYSIS
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Under conditions of TiCl4 catalysis, the 3-aza-Cope rearrangement of (R)-N-(1-phenylethyl)-4-aza-2-phenylocta-2,6-diene proceeds with high diastereo- and enantio-selectivity.
- Bailey, Patrick D.,Harrison, Michael J.
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- Kolbe Anodic Decarboxylation as a Green Way to Access 2-Pyrrolidinones
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Nootropic compounds are a group of pharmacologically active pyrrolidones. These molecules, which enhance cognition properties and possess a large prescription field, are particularly interesting synthetic targets for the pharmaceutical industry. In this Article, we disclose an effective and environmentally friendly pyrrolidinone synthesis using electrosynthesis. The newly developed methodology includes a Kolbe decarboxylation, followed by an intramolecular radical cyclization and a radical-radical cross-coupling.
- Goodall, Iain,Lam, Kevin,Markó, István,Quertenmont, Mathilde,Riant, Olivier
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- Asymmetric Synthesis of Primary and Secondary β-Fluoro-arylamines using Reductive Aminases from Fungi
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The synthesis of chiral amines is of central importance to pharmaceutical chemistry, and the inclusion of fluorine atoms in drug molecules can both increase potency and slow metabolism. Optically enriched β-fluoroamines can be obtained by the kinetic resolution of racemic amines using amine transaminases (ATAs), but yields are limited to 50 %, and also secondary amines are not accessible. In order to overcome these limitations, we have applied NADPH-dependent reductive aminase enzymes (RedAms) from fungal species to the reductive amination of α-fluoroacetophenones with ammonia, methylamine and allylamine as donors, to yield β-fluoro primary or secondary amines with >90 % conversion and between 85 and 99 % ee. In addition, the effect of the progressive introduction of fluorine atoms to the α-position of the acetophenone substrate reveals the effect of mono-, di- and tri-fluorination on the proportion of amine and alcohol in product mixtures, shedding light on the promiscuous ability of imine reductase (IRED)-type dehydrogenases to reduce fluorinated acetophenones to alcohols.
- González-Martínez, Daniel,Cuetos, Aníbal,Sharma, Mahima,García-Ramos, Marina,Lavandera, Iván,Gotor-Fernández, Vicente,Grogan, Gideon
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p. 2421 - 2425
(2020/03/25)
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- N,2,3,4-Tetrasubstituted Pyrrolidines through Tandem Lithium Amide Conjugate Addition/Radical Cyclization/Oxygenation Reactions
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Enantioselective syntheses of densely functionalized pyrrolidines deriving their chirality from (R)-1-(phenyl)ethylamine are reported. Allylic amines and β-substituted-α,β-unsaturated esters are used as the building blocks in this one-pot reaction. Single
- Kafka, Franti?ek,Pohl, Radek,Císa?ová, Ivana,Mackman, Richard,Bahador, Gina,Jahn, Ullrich
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supporting information
p. 3862 - 3871
(2016/08/16)
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- A novel and concise synthetic access to chiral 2-substituted-4-piperidone
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A novel and concise synthetic access to enantiopure chiral 2-aryl/alkyl substituted 4-piperidone has been demonstrated. This new route features two key steps: the highly diastereoselective conjugate addition of homochiral lithium amides to trans-β-substituted-α,β-unsaturated methyl esters guaranteed the enantiopurity at 2 position (de >19:1) and the intramolecular attacking of carbanions to methyl esters led to the formation of the piperidone ring. A wide range of substrates, including chiral 2-aryl and 2-alkyl-4-piperidones, were successfully synthesized with modest to high yield. Moreover, some non-chiral 3-substituted-4-piperidones were also synthesized with enhanced ring-formation yield, implicating the versatility of this method in construction of various piperidine rings.
- Chen, Bai-Ling,Wang, Bing,Lin, Guo-Qiang
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p. 945 - 953
(2014/07/21)
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- Oxidative catalysis using the stoichiometric oxidant as a reagent: An efficient strategy for single-electron-transfer-induced tandem anion-radical reactions
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Oxidative single-electron transfer-catalyzed tandem reactions consisting of a conjugate addition and a radical cyclization are reported, which incorporate the mandatory terminal oxidant as a functionality into the product. Making waste a functionality: Ox
- Kafka, Frantisek,Holan, Martin,Hidasova, Denisa,Pohl, Radek,Klepetarova, Blanka,Jahn, Ullrich,Cisarova, Ivana
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supporting information
p. 9944 - 9948,5
(2014/10/15)
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- Structure guided design of a series of sphingosine kinase (SphK) inhibitors
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Sphingosine-1-phosphate (S1P) signaling plays a vital role in mitogenesis, cell migration and angiogenesis. Sphingosine kinases (SphKs) catalyze a key step in sphingomyelin metabolism that leads to the production of S1P. There are two isoforms of SphK and observations made with SphK deficient mice show the two isoforms can compensate for each other's loss. Thus, inhibition of both isoforms is likely required to block SphK dependent angiogenesis. A structure based approach was used to design and synthesize a series of SphK inhibitors resulting in the identification of the first potent inhibitors of both isoforms of human SphK. Additionally, to our knowledge, this series of inhibitors contains the only sufficiently potent inhibitors of murine SphK1 with suitable physico-chemical properties to pharmacologically interrogate the role of SphK1 in rodent models and to reproduce the phenotype of SphK1 (-/-) mice.
- Gustin, Darin J.,Li, Yihong,Brown, Matthew L.,Min, Xiaoshan,Schmitt, Mike J.,Wanska, Malgorzata,Wang, Xiaodong,Connors, Richard,Johnstone, Sheere,Cardozo, Mario,Cheng, Alan C.,Jeffries, Shawn,Franks, Brendon,Li, Shyun,Shen, Shanling,Wong, Mariwil,Wesche, Holger,Xu, Guifen,Carlson, Timothy J.,Plant, Matthew,Morgenstern, Kurt,Rex, Karen,Schmitt, Joanna,Coxon, Angela,Walker, Nigel,Kayser, Frank,Wang, Zhulun
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p. 4608 - 4616
(2013/08/15)
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- 1,1′-Binaphthyldiamine-based lewis bases as readily available and efficient grganocatalysts for the reduction of N-Aryl and N-Alkyl ketimines
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The development of simple, low-cost, efficient, and sustainable routes to enantiomerically pure amines is a topic of extraordinary interest, specially in view of future industrial applications. In this context, we wish to report a chemical and stereochemical efficient synthesis of chiral amines through the Lewis base activated trichlorosilane reduction of ketimines. An organocatalyst, easily prepared in a single step through the condensation of picolinic acid and commercially available 1,1′-binaphthyldiamine, is the key element of this metal-free methodology, that allowed the synthesis of chiral secondary and primary amines in high yields and stereose-lectivity. Noteworthy, such catalysts are able to promote the reduction of N-alkyl ketimines, often in quantitative yield and up to 87% enantioselectivity; it: is worth mentioning that for such transformations only one other organocatalytic system has been reported so far.
- Guizzett, Stefania,Benaglia, Maurizio,Celentano, Giuseppe
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experimental part
p. 3683 - 3687
(2009/12/03)
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- Diastereocontrolled synthesis of enantioenriched 3,4-disubstituted β-prolines
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Enantioenriched 3,4-disubstituted β-prolines have been prepared with a high diastereocontrol through a carbometalation reaction or through a domino Michael addition/carbometalation reaction.
- Denes, Fabrice,Perez-Luna, Alejandro,Chemla, Fabrice
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p. 398 - 406
(2007/10/03)
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- Cyclisation of (R)- and (S)-N-allyl-N-(1-phenylethyl)methoxycarbonylacetamide mediated by Mn(III): Preparation and structural assignment of 3-aza-2-oxobicyclo[3.1.0]hexanes
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(R)- and (S)-N-allyl-N-(1-phenylethyl)methoxycarbonylacetamide, 5 and 6, underwent oxidative cyclisation mediated by Mn(III), to give easily separable diastereomeric mixtures of 3-aza-2-oxobicyclo[3.1.0]hexanes 8a,b and 9a,b, respectively, whose structure
- Galeazzi, Roberta,Geremia, Silvano,Mobbili, Giovanna,Orena, Mario
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p. 3573 - 3584
(2007/10/03)
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- Diastereoselective Preparation of Chiral Lithiated Allyl Amines: Application in EPC-Synthesis
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Lithiation of chiral allylamine (R)-1 with BunLi and ButLi leads to the formation of intermediate (R)-2, which by reaction with D2O, Me2CO or (CH2)5CO affords the expected chiral compounds (R)-3, (R)-4 and (R)-5, respectively.With Bu
- Yus, Miguel,Foubelo, Francisco,Falvello, Larry R.
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p. 2081 - 2092
(2007/10/03)
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