Syntheses of amide based anion receptors and investigation of their associations with anions and their molecular structures using proton NMR titration and DFT methods
摘要:
The synthesized disubstituted isophthalamide and pyridine-2,6dicarboxamide derivatives of nine compounds were prepared. Their association constants with tetrabutylammonium fluoride (TBA center dot F), tetrabutylammonium chloride (TBA center dot Cl), tetrabutylammonium bromide (TBA center dot Br), tetrabutylammonium dihydrogenphosphate (TBA center dot H2PO4), tetrabutylammonium hydrogensulphate (TBA center dot HSO4) and tetrabutylammonium nitrate (TBA center dot NO3) were obtained by H-1 NMR titration technique. The optimized structures of compounds 1-9 and their association with F-, Cl-, Br-, H2PO4-, HSO4- and NO3- were obtained using the B3LYP/6-31+G(d) method. The most favorable complex of compound 3 with Br- was found. The high association constants of complexes 1-6 with F- are expected. Associations of all receptors with anions are exothermic and spontaneous reactions. Thermodynamic properties of all associations obtained using B3LYP/6-31+G(d) method are reported. (C) 2013 Elsevier B.V. All rights reserved.
[EN] MOLECULAR EDITING OF MULTIPLE C-H BONDS BY LEVERAGING RECOGNITION OF DISTANCE, GEOMETRY AND CHIRALITY [FR] ÉDITION MOLÉCULAIRE DE LIAISONS C-H MULTIPLES PAR EXPLOITATION DE LA RECONNAISSANCE DE LA DISTANCE, DE LA GÉOMÉTRIE ET DE LA CHIRALITÉ
摘要:
This disclosure provides functional templates that direct Pd to functionalize multiple C-H bonds in polycyclic aza-arenes such as quinolines and related heterocycles at locations that are difficult to isolate and reach for substitution. Herein disclosed are two conceptually distinct directing templates (T) that enable site- selective C6 and C7-H activation of polycyclic aza-arenes. These catalytic pyridine-based templates recruit the aza-arene substrate throughN-coordination, enabling the directing arm to deliver the catalyst and precisely activate remote and adjacent C6 or C7-H bond (Fig. 1d). In parallel, we discovered that the use of a simple and readily prepared template chaperone (TC) can turn over the directing template, allowing it to be used catalytically for the first time. Notably, chiral recognition is vital in the granular discrimination between competing C3 and C7-H bonds when the differentiation via distance and geometry is insufficient. Thus, precise recognition of a directing template's distance, geometry and chirality now enables the iterative C-H editing of quinoline and related pharmacophores at any desired site and order. The methods disclosed herein can also be used for diverse and late-stage modification of heterocycle-based drug molecules and pharmacophores.
Synthesis and NMR Binding Studies towards Rational Design of a Series of Electron-Withdrawing Diamide Receptors/Organocatalysts
作者:Michael Kinsella、Patrick G. Duggan、Jimmy Muldoon、Kevin S. Eccles、Simon E. Lawrence、Claire M. Lennon
DOI:10.1002/ejoc.201001439
日期:2011.2
A related series of bisamides have been evaluated for rational correlation between anion complexation and organocatalysis: remarkable enhancement of hydrogen bonding to anions was observed along with significant increases in catalytic activity in the Baylis–Hillman reaction. In addition, X-ray crystallography showed a large degree of pre-organisation was observed in one receptor by incorporation of
SENSOR AND METHOD OF DETECTING AN ANALYTE USING 19F NMR
申请人:Massachusetts Institute of Technology
公开号:US20160018344A1
公开(公告)日:2016-01-21
A sensor including a fluorinated receptor can be used to identify an analyte through shift in
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F NMR resonance of the receptor when the receptor interacts with the analyte.