Ruthenium-NHC-Catalyzed Asymmetric Hydrogenation of Flavones and Chromones: General Access to Enantiomerically Enriched Flavanones, Flavanols, Chromanones, and Chromanols
作者:Dongbing Zhao、Bernhard Beiring、Frank Glorius
DOI:10.1002/anie.201302573
日期:2013.8.5
Two to four! Readily available flavones and chromones were efficiently converted into four valuable chiral classes of O‐heterocycles—flavanones, chromanones, flavanols, and chromanols—by means of an enantioselective Ru/NHC‐catalyzed hydrogenation process (see scheme; NHC=N‐heterocyclic carbene, PCC=pyridinium chlorochromate).
One-pot synthesis of 3-(furan-2-yl)-4H-chromen-4-ones from 1-(2-hydroxyphenyl)butane-1,3-diones and 2,5-dimethoxy-2,5-dihydrofuran catalyzed via K10 montmorillonite under solvent-free conditions
A new, concise and efficient method of one-potsynthesis of 3-(furan-2-yl)-4H-chromen-4-ones was developed using K10 montmorillonite catalysis undersolvent-freeconditions.
Synthesis of functionalized chromones via organocatalysis
作者:Sai-Shuai Wen、Jing Wang、Yi-Ming Luo、Hua Yang
DOI:10.1016/j.tet.2014.10.045
日期:2014.12
A facile and versatile organocatalytic approach to access 2-substituted and 2,3-disubstituted chromone derivatives under mild conditions was developed, which was effectively catalyzed by novel proline phenylsulphonylhydrazide or pyrrolidine. As a result, diversely functionalized chromones were obtained in up to 99% yield. In addition, further modification of the corresponding chromones afforded novel polycyclic chromones. (C) 2014 Elsevier Ltd. All rights reserved.
A Convenient Synthesis of 2- and 2,3-Substituted 4<i>H</i>-Chromen-4-ones