- Shuttle arylation by Rh(I) catalyzed reversible carbon–carbon bond activation of unstrained alcohols
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The advent of transfer hydrogenation and borrowing hydrogen reactions paved the way to manipulate simple alcohols in previously unthinkable manners and circumvented the need for hydrogen gas. Analogously, transfer hydrocarbylation could greatly increase the versatility of tertiary alcohols. However, this reaction remains unexplored because of the challenges associated with the catalytic cleavage of unactivated C–C bonds. Herein, we report a rhodium(I)-catalyzed shuttle arylation cleaving the C(sp2)–C(sp3) bond in unstrained triaryl alcohols via a redox-neutral β-carbon elimination mechanism. A selective transfer hydrocarbylation of substituted (hetero)aryl groups from tertiary alcohols to ketones was realized, employing benign alcohols as latent C-nucleophiles. All preliminary mechanistic experiments support a reversible β-carbon elimination/migratory insertion mechanism. In a broader context, this novel reactivity offers a new platform for the manipulation of tertiary alcohols in catalysis.
- Lutz, Marius D.R.,Gasser, Valentina C.M.,Morandi, Bill
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supporting information
p. 1108 - 1119
(2021/04/19)
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- Oxidative gold catalysis meets photochemistry - Synthesis of benzo[a]fluorenones from diynes
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Diynes bearing one terminal and one triarylmethylsubstituted alkyne were converted into complex benzofluorenone derivatives via a one-pot process involving a gold-catalyzed step followed by a photocyclization/oxidation. In the first step an Noxide was used to position-selectively generate an a-oxo carbenoid at the terminal alkyne which after a regioselective 1,6-carbene transfer along the tethered tritylalkyne and a subsequent aryl 1,2-shift furnished tetraphenylethylene-like derivatives. These intermediates were successfully transformed to fluorenones via oxidative photocyclization.
- N?sel, Pascal,Moghimi, Setareh,Hendrich, Christoph,Haupt, Marten,Rudolph, Matthias,Rominger, Frank,Hashmia, A. Stephen K.
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supporting information
p. 3755 - 3760
(2015/01/09)
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- Synthesis of symmetrical ketones from Grignard reagents and 1,1′-carbonyldiimidazole
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Coupling reactions of 1,1′-carbonyldiimidazole with Grignard reagents provide a rapid and straightforward method for the synthesis of symmetrical ketones. Georg Thieme Verlag Stuttgart.
- Bottalico, Daniela,Fiandanese, Vito,Marchese, Giuseppe,Punzi, Angela
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experimental part
p. 2316 - 2318
(2010/02/28)
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- Novel inhibitors of the gardos channel for the treatment of sickle cell disease
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Sickle cell disease (SCD) is a hereditary condition characterized by deformation of red blood cells (RBCs). This phenomenon is due to the presence of abnormal hemoglobin that polymerizes upon deoxygenation. This effect is exacerbated when dehydrated RBCs experience a loss of both water and potassium salts. One critical pathway for the regulation of potassium efflux from RBCs is the Gardos channel, a calcium-activated potassium channel. This paper describes the synthesis and biological evaluation of a series of potent inhibitors of the Gardos channel. The goal was to identify compounds that were potent and selective inhibitors of the channel but had improved pharmacokinetic properties compared to 1, Clotrimazole. Several triarylamides such as 10 and 21 were potent inhibitors of the Gardos channel (IC50 of 10 nM) and active in a mouse model of SCD. Compound 21 (ICA-17043) was advanced into phase 3 clinical trials for SCD.
- McNaughton-Smith, Grant A.,Burns, J. Ford,Stocker, Jonathan W.,Rigdon, Gregory C.,Creech, Christopher,Arlington, Susan,Shelton, Tara,De Franceschi, Lucia
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p. 976 - 982
(2008/12/20)
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- Design, synthesis and evaluation of substituted triarylnipecotic acid derivatives as GABA uptake inhibitors: Identification of a ligand with moderate affinity and selectivity for the cloned human GABA transporter GAT- 3
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γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian central nervous system. Molecular biology has revealed the presence of four high-affinity GABA transporters in the brain, GAT-1, GAT-2, GAT-3, and BGT-1, the latter transporting both GABA and the osmolyte Betaine. We have shown that known GABA uptake inhibitors such as SK and F 89976-A, CI- 966, and Tiagabine exhibit high affinity and selectivity for GAT-1. In the present paper we describe the design and synthesis of a novel series of triarylnipecotic acid derivatives for evaluation as GABA uptake inhibitors. The design lead for this series of compounds was the nonselective GABA uptake inhibitor EGYT-3886, [(-)-2-phenyl-2-[(dimethylamino)ethoxy]-(1R)-1,7,7- trimethylbicyclo[2.2.1]heptane]. From this series of compounds (S)-1-[2- [tris(4-methoxyphenyl)methoxy]ethyl]-3-piperidinecarboxylic acid, 4(S) was identified as a novel ligand with selectivity for GAT-3. 4(S) displayed an IC50 of 5 μM at GAT-3, 21 μM at GAT-2, >200 μM at GAT-1, and 140 μM at BGT-1. This compound will be an important tool for evaluating the role of GAT-3 in neural function.
- Dhar,Borden,Tyagarajan,Smith,Branchek,Weinshank,Gluchowski
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p. 2334 - 2342
(2007/10/02)
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- Synthesis and antifungal activity of a series of difluorotritylimidazoles
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1-[(2-Fluorophenyl)(4-fluorophenyl)phenylmethyl]-1H-imidazole (flutrimazole, UR-4056, CAS 119006-77-8) (15) was selected among a series of mono-, di- and trifluorotrityl-imidazole antifungal agents as the most potent fluorine containing analogue of clotrimazole.
- Bartroli,Alguero,Boncompte,Forn
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p. 832 - 835
(2007/10/02)
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