23116-94-1Relevant academic research and scientific papers
Diversity oriented approach to crownophanes by enyne metathesis and Diels-Alder reaction as key steps
Kotha, Sambasivarao,Waghule, Gopalkrushna T.
, p. 6314 - 6318 (2012)
Various crownophanes are assembled starting with simple phenol derivatives such as catechol, resorcinol, and hydroquinone. Here, cross-enyne metathesis (CEM) and Diels-Alder (DA) reaction have been used as key steps. This strategy has embedded six diversi
Probing the Existence of a Metastable Binding Site at the β2-Adrenergic Receptor with Homobivalent Bitopic Ligands
Gaiser, Birgit I.,Danielsen, Mia,Marcher-R?rsted, Emil,R?pke J?rgensen, Kira,Wróbel, Tomasz M.,Frykman, Mikael,Johansson, Henrik,Br?uner-Osborne, Hans,Gloriam, David E.,Mathiesen, Jesper Mosolff,Sejer Pedersen, Daniel
, p. 7806 - 7839 (2019/09/07)
Herein, we report the development of bitopic ligands aimed at targeting the orthosteric binding site (OBS) and a metastable binding site (MBS) within the same receptor unit. Previous molecular dynamics studies on ligand binding to the β2-adrenergic receptor (β2AR) suggested that ligands pause at transient, less-conserved MBSs. We envisioned that MBSs can be regarded as allosteric binding sites and targeted by homobivalent bitopic ligands linking two identical pharmacophores. Such ligands were designed based on docking of the antagonist (S)-alprenolol into the OBS and an MBS and synthesized. Pharmacological characterization revealed ligands with similar potency and affinity, slightly increased β2/β1AR-selectivity, and/or substantially slower β2AR off-rates compared to (S)-alprenolol. Truncated bitopic ligands suggested the major contribution of the metastable pharmacophore to be a hydrophobic interaction with the β2AR, while the linkers alone decreased the potency of the orthosteric fragment. Altogether, the study underlines the potential of targeting MBSs for improving the pharmacological profiles of ligands.
A study towards the regioselective synthesis of the e,e,e trisadduct of C60 via the [4+2] Diels-Alder reaction with tethers bearing orthoquinodimethane precursors
Ioannou, Charalambos P.,Chronakis, Nikos
, p. 65 - 82 (2015/04/21)
The regioselective synthesis of an e,e,e trisadduct of C60 via the Diels-Alder reaction with orthoquinodimethanes has been attempted employing the tether-directed remote functionalization approach. Opened-structure tether 10 and macrocyclic tethers 16 and 21 were synthesized for this purpose. The functionalization of C60 afforded inseparable mixtures of regiomeric trisadducts and the regioselective formation of the e,e,e trisadduct was not feasible even when the more preorganized tethers 16 and 21 were employed. The in situ thermal generation of orthoquinodimethanes from the 1,2-bis(bromomethyl)benzene precursors requires high temperatures and is followed by fast, irreversible cycloaddition with C60 to afford thermally stable products, which prevents the achievement of high regioselectivities.
Highly efficient synthesis of tetra benzo spiro bis-crown ether
Moradgholi, Fatemeh,Vahedi, Hooshang,Lari, Jalil
, p. 85 - 90 (2015/06/23)
Novel spiro bis-crown ethers derivatives with four benzo units connected via one carbon bridges have been prepared. These compounds represent well preorganized cavities with interesting complexation abilities towards cations. These macrocyclic were prepared by a four-step via template method by utilizing simple precursors catechol, oliethylen glycol and penta erythritol tetra bromide in good yield. Additionally, cesium carbonate could be used as an excellent base for these reactions.
Application of Bayer-Villiger reaction to the synthesis of dibenzo-18-crown-6, dibenzo-21-crown-7 and dihydroxydibenzo-18-crown-6
Utekar, Druman R.,Samant, Shriniwas D.
, p. 193 - 197 (2014/05/06)
Dibenzo-18-crown-6, dibenzo-21-crown-7 and dihydroxy dibenzo-18-crown-6 were synthesized by Bayer-Villiger oxidation strategy. Dibenzo-18-crown-6 and dibenzo-21-crown-7 could be synthesized through a three-step protocol starting from salicylaldehyde. Salicylaldehyde was reacted with bis-(2-chloroethyl)ether using K2CO3 in acetonitrile to link the two phenolic groups with the oxyethylene bridge followed by conversion of the formyl group to the hydroxy group via a Baeyer-Villiger reaction and finally linking the two phenolic group with appropriate oxyethylene bridge. The two target crown ethers were obtained in overall yield, 24% and 30%, respectively. This method has a great potential for synthesis of symmetrical as well as unsymmetrical dibenzo crowns with varying oxyethylene bridges. Baeyer-Villiger oxidation could be used to prepare dihydroxy derivative of dibenzo-18-crown-6 through acetylation of dibenzo-18-crown-6 followed by Baeyer-Villiger oxidation. The Baeyer-Villiger oxidation could be substantially accelerated using trifluoroacetic acid.
Microwave-assisted synthesis of dibenzo-crown ethers
Torrejos, Rey Eliseo C.,Nisola, Grace M.,Beltran, Arnel B.,Park, Myoung Jun,Patil, Basavaraj R.,Lee, Seong-Poong,Seo, Jeong Gil,Chung, Wook-Jin
, p. 109 - 115 (2014/03/21)
Microwave-assisted organic synthesis (MAOS) for dibenzo-substituted crown ethers is presented. Two routes were developed: (1) one-pot MAOS for symmetric dibenzo-crown ethers (DBC) and (2) a two-step MAOS via diphenol intermediates for both symmetric and asymmetric DBCs. MAOS were carried out in open or closed vessels, with or without temperature control at various microwave settings using different bases and reactants. Open vessel MAOS was limited by the volatility of reactants hence was less preferred than the closed vessel MAOS. DBC formation was highly affected by the cation size of the base, which acted as a template ion during DBCs ring closure. Closed vessel MAOS without temperature control was found most appropriate for DBC synthesis. Symmetric DBCs were conveniently obtained via one-pot MAOS whereas asymmetric DBCs were obtained from two-step MAOS via diphenol intermediates. The method was found expedient as it afforded satisfactory yields at considerably shorter reaction time than those in conventional methods.
Polybenzocrown ethers: Synthesis by cesium-assisted cyclization and solid-state structures
Hanes, Robert E.,Ellingsworth, Edward C.,Griffin, Scott T.,Rogers, Robin D.,Bartsch, Richard A.
, p. 217 - 237,21 (2020/08/24)
A series of large-ring polybenzocrown ethers is prepared by cesium-assisted cyclizations. Reactions of diphenols/bisphenols, dimesylates of oligoethylene glycols and cesium carbonate in MeCN produce the large-ring polybenzocrown ethers in high yields. To gain further insight into the structures of these compounds, solid-state structures of three large-ring crown ethers are obtained by X-ray diffraction.
Tribenzo[27]crown-9: A new ring for dibenzylammonium rods
Cantrill, Stuart J.,Fyfe, Matthew C. T.,Heiss, Aaron M.,Stoddart, J. Fraser,White, Andrew J. P.,Williams, David J.
, p. 61 - 64 (2007/10/03)
(formula presented) Dibenzylammonium (DBA+) ions thread through the cavity of tribenzo[27]crown-9 (TB27C9) to generate [2]pseudorotaxanes that are stabilized principally by hydrogen-bonding interactions. The stabilities and complexation kinetic
Radiochemical stability of the dicyclohexano-18-crown-6 ether (DCH18C6): Synthesis and tests in radioactive medium of the DCH18C6 radiolytic products
Draye, Micheline,Favre-Reguillon, Alain,Chomel, Rodolph,Faure, Rene,Guy, Alain,Foos, Jacques,Lemaire, Marc
, p. 183 - 197 (2007/10/03)
The cis-syn-cis isomer of the dicyclohexano-18-crown-6 ether (DCH18C6) was subjected to hydrolysis and radiolysis with a 137Cs gamma source, at different doses of irradiation. The cis-syn-cis DCH18C6 radiolytic products previously identified [1], were synthesized in their different configurations. These radiolytic products, all of cis configuration, were tested on aqueous synthetic solutions of spent nuclear fuels. Experiments in radioactive medium showed that, under continuous extraction conditions, the cis-syn-cis DCH18C6 radiolytic products cannot perturb a reprocessing process using the DCH18C6 as selective extractant. Good prospects for the application of DCH18C6 to spent nuclear fuel reprocessing were therefore demonstrated. An X-ray crystallographic study of the DCH18C6 cis-syn-cis-isomer with uranyl nitrate was investigated. Elsevier,.
DISUBSTITUTED DIBENZOCROWN ETHERS
Ardeleanu, Rodinel,Voiculescu, Nicolae,Marcu, Mihai,Calimente, Daniel,Oghina, Radu
, p. 471 - 474 (2007/10/02)
A dibenzocrown ether with 18-membered ring, 2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclooctadeca-2, 11-diene or dibenzo-18-crown-6, was synthesized through alkylation of catechol with bis (2-chloroethyl) ether, in the presence of a mixture of NaOH and CH3-OH, in n-butanol.This dibenzocrown ether was converted into the diacetyl derivative, which in the presence of sodium hydroxide and bromine gave the dicarboxyl derivative.
