Search results for "Chroman"
showing 10 items of 25 documents
CCDC 270497: Experimental Crystal Structure Determination
2005
Related Article: D.Schollmeyer, B.Kammerer, C.Peifer, S.Laufer|2005|Acta Crystallogr.,Sect.E:Struct.Rep.Online|61|o868|doi:10.1107/S1600536805006124
CCDC 1966749: Experimental Crystal Structure Determination
2019
Related Article: K. Suchojad, A. Dołęga, A. Adamus-Grabicka, E. Budzisz, M. Małecka|2019|Acta Crystallogr.,Sect.E:Cryst.Commun.|75|1907|doi:10.1107/S2056989019015639
CCDC 1966750: Experimental Crystal Structure Determination
2019
Related Article: K. Suchojad, A. Dołęga, A. Adamus-Grabicka, E. Budzisz, M. Małecka|2019|Acta Crystallogr.,Sect.E:Cryst.Commun.|75|1907|doi:10.1107/S2056989019015639
CCDC 149386: Experimental Crystal Structure Determination
2001
Related Article: Herbert Meier, Michael Schmidt, Axel Mayer, Dieter Schollmeyer and Bernhard Beile|2012|J.Heterocycl.Chem.|49|516|doi:10.1002/jhet.789
CCDC 916051: Experimental Crystal Structure Determination
2013
Related Article: Gonzalo Blay, M. Carmen Muñoz, José R. Pedro, Amparo Sanz-Marco|2013|Adv.Synth.Catal.|355|1071|doi:10.1002/adsc.201201120
CCDC 140963: Experimental Crystal Structure Determination
2000
Related Article: K.Ejsmont, J.Kyziol, E.Nowakowska, J.Zaleski|2000|Acta Crystallogr.,Sect.C:Cryst.Struct.Commun.|56|93|doi:10.1107/S0108270199013190
Water-Tolerant Trifloaluminate Ionic Liquids: New and Unique Lewis Acidic Catalysts for the Synthesis of Chromane
2018
The first example of triflometallate ionic liquids, named in analogy to chlorometallate ionic liquids, is reported. Trifloaluminate ionic liquids, synthesised from 1-alkyl-3-methylimidazolium triflates and aluminium triflate, were characterised by multinuclear NMR spectroscopy and FT-IR spectroscopy, revealing the existence of oligonuclear, multiply-charged trifloaluminate anions, with multiple bridging triflate modes. Acceptor numbers were determined to quantify their Lewis acidity, rendering trifloaluminate ionic liquids as medium-strength Lewis acids (AN = ca. 65). Used as acidic catalysts in the cycloaddition of 2,4-dimethylphenol and isoprene (molar ratio 2:1) to prepare chromane, trif…
Asymmetric Synthesis of Functionalized Tricyclic Chromanes via an Organocatalytic Triple Domino Reaction
2017
A highly stereoselective triple domino reaction for the synthesis of functionalized tricyclic chromane scaffolds has been developed. A secondary amine-catalyzed domino Michael/Michael/aldol condensation reaction between aliphatic aldehydes, nitro-chromenes, and α,β-unsaturated aldehydes leads to the formation of synthetically important tricyclic chromanes bearing four contiguous stereogenic centers including a tetrasubstituted carbon in good yields (20–66%) and excellent stereoselectivities (>20:1 dr and >99% ee).
Organocatalytic Domino Oxa-Michael/1,6-Addition Reactions: Asymmetric Synthesis of Chromans Bearing Oxindole Scaffolds.
2016
An asymmetric organocatalytic domino oxa-Michael/1,6-addition reaction of ortho-hydroxyphenyl-substituted para-quinone methides and isatin-derived enoates has been developed. In the presence of 5 mol % of a bifunctional thiourea organocatalyst, this scalable domino reaction affords 4-phenyl-substituted chromans bearing spiro-connected oxindole scaffolds and three adjacent stereogenic centers in good to excellent yields (up to 98 %) and with very high stereoselectivities (up to >20:1 d.r., >99 % ee).
Crystal structures of (E)-3-(4-hydroxybenzylidene)chroman-4-one and (E)-3-(3-hydroxybenzylidene)-2-phenylchroman-4-one
2019
The synthesis and crystal structures of (E)-3-(4-hydroxybenzylidene)chroman-4-one, C16H12O3, I, and (E)-3-(3-hydroxybenzylidene)-2-phenylchroman-4-one, C22H16O3, II, are reported. These compounds are of interest with respect to biological activity. Both structures display intermolecular C—H...O and O—H...O hydrogen bonding, forming layers in the crystal lattice. The crystal structure of compound I is consolidated by π–π interactions. The lipophilicity (logP) was determined as it is one of the parameters qualifying compounds as potential drugs. The logP value for compound I is associated with a larger contribution of C...H interaction in the Hirshfeld surface.