[EN] CHROMEN-4-ONE DERIVATIVES FOR THE TREATMENT AND PROPHYLAXIS OF HEPATITIS B VIRUS DISEASE [FR] DÉRIVÉS DE CHROMEN-4-ONE POUR LE TRAITEMENT ET LA PROPHYLAXIE D'UNE MALADIE DUE AU VIRUS DE L'HÉPATITE B
efficient route for the coupling of maleimides with chromones at the C5-position has been developed under Ru(II) catalysis. It could provide 1,4-addition products and oxidative Heck-type products by switching additives. Benzoic acid led to the formation of 1,4-addition products under solvent-free conditions, and silver acetate was promoted to the generation of oxidative Heck-type products. Various maleimides
The selective preparation of 5‐alkylated and 5‐alkenylated chromones from readily accessible substrates using Rh(III) and Ru(II) catalysts has been successfully developed. Forty‐one examples of the target compounds were obtained in up to 95 % yield.
NIS/TBHP Induced Regioselective Selenation of (Hetero)Arenes
<i>via</i>
Direct C−H Functionalization
作者:Chaochao Ding、Yuanzu Yu、Qiongli Yu、Zixin Xie、Yan Zhou、Jianmin Zhou、Guang Liang、Zengqiang Song
DOI:10.1002/cctc.201801548
日期:2018.12.7
A simple and efficient method for the regioselective selenation of (hetero)arenes via direct C−Hfunctionalization has been established using NIS and TBHP. The present protocol is compatible with different functional groups, and suitable for various (hetero)arenes and diselenides, efficiently affording the desired products in moderate to excellent yields.
Synthesis of 2<i>H</i>-Chromenes through the Reduction of Chromones with 9-BBN
作者:Tetsuya Eguchi、Yukio Hoshino
DOI:10.1246/bcsj.74.967
日期:2001.5
reduced to 2H-1-benzopyrans through the 1,2-addition of 9-borabicyclo[3.3.1]nonane. Although transition-metal complexes did not have a catalytic effect on the reaction, only by using palladium(II) chloride, could both 2H-1-benzopyran and dihydro-1-benzopyran be obtained to a similar extent. Also, the reduction of chromone using other organoboranes led not to 2H-1-benzopyran, but rather to chromanone through