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Conformational control of aliphatic oligoketones bearing two 1,3-diketone subunits is achieved by molecular recognition with pillar[5]arene. Pillar[5]arene binds to aliphatic ketones, with association constants of ∼10 M, to form pseudorotaxanes. The pseudorotaxanes are locked by BF complexation at the 1,3-diketone sites through quasi-solid-state reactions. X-ray crystallography reveals linear conformations for the axis molecules. The effect of supramolecular conformational restriction is evaluated using an alkyl-linked dyad chromophore system that shows solvatochromism upon intramolecular aggregation.
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http://dx.doi.org/10.1021/acs.orglett.0c01010 | DOI Listing |
Org Lett
September 2025
School of Pharmaceutical and Chemical Engineering and Institute for Advanced Studies, Taizhou University, 1139 Shifu Road, Taizhou, Zhejiang 318000, China.
Here, intramolecular hydrogen bond (IMHBs)-induced rigidity is used for the first time to synthesize macrocyclic arenes. Calix[]azanediyldibenzoates (C[]A, where = 3, 4, or 5) are synthesized through a one-step condensation reaction between dimethyl 2,2'-azanediyldibenzoate and paraformaldehyde. Compared to the monomer, the macrocycles exhibit a fast and significant acidochromic response due to the intramolecular charge transfer that is boosted by the synergistic effect of their adsorption and protonation.
View Article and Find Full Text PDFJ Comput Aided Mol Des
September 2025
Supramolecular and Catalysis Lab, Department of Natural Products Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai, Tamil Nadu, India.
TGF-β receptor I kinase plays a significant role in cancer biology and is a well-established target for cancer drug development, as evidenced by active molecules like Galunisertib (LY2157229). Computational studies were conducted to analyse the catalytic site of TGF-β receptor I kinase, identifying key amino acid residues essential for binding. Based on these findings, Alicyclic fused pyrazole derivatives were designed.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Enzymes catalyze chemical reactions with remarkable rate enhancements and selectivity. Supramolecular catalysis seeks to understand and emulate these outcomes, leveraging noncovalent interactions, electric fields, and controlled active site microenvironments to enhance catalysis in an enzyme-like fashion. The effects of conformational dynamics on supramolecular catalysts and assemblies are, however, relatively unexplored, despite their crucial role in enzyme rate enhancement.
View Article and Find Full Text PDFDalton Trans
September 2025
University of Patras, Department of Chemistry, 26504 Patras, Greece.
With the aim of assessing the role and impact of pseudohalides on the molecular and supramolecular structures of copper(II)/heavily substituted imidazole complexes, the synthesis and characterization of the complexes {[Cu(N)(HL)]} (1), {[Cu{N(CN)}(HL)]·MeCO} (2·MeCO) and [Cu(NCO)(HL)]·MeCN (3·MeCN) have been carried out; HL is the 4,5-diphenylimidazole ligand. The organic molecule behaves as a monodentate ligand through the pyridine-type nitrogen atom of the imidazole ring. The 1D polymer 1 is made up of undulating {-Cu-(N)-Cu-(N)-} chains, with the HL ligands extending from both sides of the chains.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH, 43210, USA.
We describe the preparation, conformational dynamics, and stereoselective recognition characteristics of water-soluble pillar[6]arenes pS-2 and pR-2. These two novel and diastereomeric cavitands comprise a 2,5-bis(ethoxy)pillar[6]arene core with one of six phenylene ring conjugated to two hexaanionic dendrons. Each dendron includes an (S)-glutamic acid amidated with two tris-carboxylic Behera's amines.
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