Catalytic Enantioselective Synthesis of Flavanones and Chromanones
摘要:
The enantioselective synthesis of flavanones and chromanones is described. Bifunctional thiourea catalysts promote an asymmetric oxo-conjugate addition to a beta-ketoester alkylidene in high yields with excellent enantioselectivity (80-94% ee) for aryl and alkyl substrates. Decarboxylation of the beta-ketoester proceeds smoothly in a one-pot procedure to afford the enantioenriched flavanones and chromanones.
Asymmetric Ion-Pairing Catalysis of the Reversible Cyclization of 2′-Hydroxychalcone to Flavanone: Asymmetric Catalysis of an Equilibrating Reaction
作者:Lukas Hintermann、Claudia Dittmer
DOI:10.1002/ejoc.201200838
日期:2012.10
The asymmetric catalytic cyclization of the simple 2′-hydroxychalcone (1) to flavanone (2), a model for the chalcone isomerase reaction, has been realized as a catalytic asymmetric ion-pairing process with chiral quaternary ammonium salts (e.g., 9-anthracenylmethlycinchoninium chloride; 9-Am-CN-Cl) and NaH as small-molecule co-catalyst. In toluene/CHCl3 solution, the process reaches an intrinsic enantioselectivity
Tandem intramolecular oxa-Michael addition/decarboxylation reaction catalyzed by bifunctional cinchona alkaloids: facile synthesis of chiral flavanone derivatives
作者:Hai-Feng Wang、Hua Xiao、Xiao-Wei Wang、Gang Zhao
DOI:10.1016/j.tet.2011.05.088
日期:2011.7
Bifunctionalcinchonaalkaloids were used to catalyze a tandem intramolecular oxa-Michael addition/decarboxylation reaction of alkylidene β-ketoesters 1, providing a series of flavanone derivatives with up to 97% yield and 93% ee.
Enhanced reactivity and selectivity of asymmetric oxa-Michael addition of 2′-hydroxychalcones in carbon confined spaces
作者:Melad Shaikh、Kiran Kumar Atyam、Mahendra Sahu、Kalluri V. S. Ranganath
DOI:10.1039/c7cc01096f
日期:——
Carbon nanotubes (CNTs) are employed as nanoscale reaction vessels for the asymmetric oxa-Michael addition of 2′-hydroxychalcones.
碳纳米管(CNTs)被用作纳米级反应容器,用于2'-羟基香豆素的不对称氧-迈克尔加成反应。
Asymmetric Synthesis of Sakuranetin-Relevant Flavanones for the Identification of New Chiral Antifungal Leads
作者:Juan Yang、Jixing Lai、Wenlong Kong、Shengkun Li
DOI:10.1021/acs.jafc.1c07557
日期:2022.3.23
Discovery and efficient synthesis of new promising leads have a central role in agrochemical science. Reported herein is the sakuranetin-directed synergistic exploration of an asymmetricsynthesis and an antifungal evaluation of chiral flavanones. A new palladium catalytic system with CarOx-type ligands was successfully identified for the highly enantioselective addition of arylboronic acids to chromones
An efficient synthesis of bioactive chiralflavanones (1) was achieved through the Rh-catalyzed asymmetric1,4-addition of arylboronicacid to chromone. The reaction in toluene proceeded smoothly at room temperature in the presence of 0.5% Rh catalyst with electron-poor chiral diphosphine MeO-F12-BIPHEP. In this reaction, the 1,2-addition to (S)-1 frequently occurred to yield (2S,4R)-2,4-diaryl-4-chromanol