Ligand Optimization by Improving Shape Complementarity at a Hepatitis C Virus RNA Target
Crystal structure analysis revealed key interactions of a 2-amino-benzimidazole viral translation inhibitor that captures an elongated conformation of an RNA switch target in the internal ribosome entry site (IRES) of hepatitis C virus (HCV). Here, we have designed and synthesized quinazoline derivatives with improved shape complementarity at the ligand binding site of the viral RNA target. A spiro-cyclopropyl modification aimed at filling a pocket in the back of the RNA binding site led to a 5-fold increase of ligand affinity while a slightly more voluminous dimethyl substitution at the same position did not improve binding. We demonstrate that precise shape complementarity based solely on hydrophobic interactions contributes significantly to ligand binding even at a hydrophilic RNA target site such as the HCV IRES conformational switch.
Charrette, Brian P.,Boerneke, Mark A.,Hermann, Thomas
Exploiting Imine Photochemistry for Masked N-Centered Radical Reactivity
This report details the development of a masked N-centered radical strategy that harvests the energy of light to drive the conversion of cyclopropylimines to 1-aminonorbornanes. This process employs the N-centered radical character of a photoexcited imine to facilitate the homolytic fragmentation of the cyclopropane ring and the subsequent radical cyclization sequence that forms two new C?C bonds en route to the norbornane core. Achieving bond-forming reactivity as a function of the N-centered radical character of an excited state Schiff base is unique, requiring only violet light in this instance. This methodology operates in continuous flow, enhancing the potential to translate beyond the academic sector. The operational simplicity of this photochemical process and the structural novelty of the (hetero)aryl-fused 1-aminonorbornane products are anticipated to provide a valuable addition to discovery efforts in pharmaceutical and agrochemical industries.
Staveness, Daryl,Collins, James L.,McAtee, Rory C.,Stephenson, Corey R. J.
supporting information
p. 19000 - 19006
(2019/11/21)
2-[1-PHENYL-5-HYDROXY OR METHOXY-4ALPHA-METHYL-HEXAHYDROCLOPENTA[F]INDAZOL-5-YL]ETHYL PHENYL DERIVATIVES AS GLUCOCORTICOID RECEPTOR LIGANDS
The present invention is directed to 2- [l-phenyl-5 -hydroxy or methoxy-4alpha- methyl-hexahydrocyclopenta[f]indazol-5-yl]ethyl phenyl derivatives of formula I (I) as glucocorticoid receptor ligands useful for treating a variety of autoimmune and inflamma
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Page/Page column 27-28
(2008/12/05)
A direct synthesis of 1-aryl- and 1-alkenylcyclopropylamines from aryl and alkenyl nitriles
The reaction of various aromatic nitriles with 1.1 equiv of Ti(Oi-Pr)4 and 2.2 equiv of EtMgBr followed by addition of a Lewis acid gave 1-aryl cyclopropylamines in 43-76% yields. Under similar conditions, conjugated alkene-nitriles afford 1-alkenylcyclopropylamines (42-65%).
Bertus, Philippe,Szymoniak, Jan
p. 7133 - 7136
(2007/10/03)
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