One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na<sub>2</sub>S<sub>2</sub>O<sub>8</sub>
作者:Teppei Sasaki、Katsuhiko Moriyama、Hideo Togo
DOI:10.3762/bjoc.14.22
日期:——
Various 4-aryl-3-bromocoumarins were smoothly obtained in moderate yields in one pot by treating 3-aryl-2-propynoic acids with diaryliodonium triflates and K2CO3 in the presence of CuCl, followed by the reaction with tetrabutylammonium bromide (TBAB) and Na2S2O8. The obtained 3-bromo-4-phenylcoumarin was transformed into 4-phenylcoumarin derivatives bearing C-H, C-S, C-N, and C-C bonds at 3-position
Visible-light-mediated radical cascade reaction: synthesis of 3-bromocoumarins from alkynoates
作者:Shangbiao Feng、Jinlai Li、Zaimin Liu、Haiyu Sun、Hongliang Shi、Xiaolei Wang、Xingang Xie、Xuegong She
DOI:10.1039/c7ob02199b
日期:——
The development of a visible-light mediated bromo radical addition/spirocyclization/ester migration cascade reaction to generate 3-bromocoumarins from alkynoates is reported.
报道了一种利用可见光介导的溴自由基加成/螺环化/酯迁移串联反应,从炔酸酯生成3-溴香豆素。
Pd-catalyzed cross-coupling study of bi-functional 3-bromo-4-trifloxycoumarins with triarylbismuth reagents
作者:Maddali L.N. Rao、Abhijeet Kumar
DOI:10.1016/j.tet.2015.05.060
日期:2015.8
3-bromo-4-trifloxycoumarins have been explored with threefold arylating triarylbismuthreagents. These palladium-catalyzed reactions afforded chemo-selective C-4 arylations with the facile formation of 3-bromo-4-arylcoumarins in good to high yields. Additionally, palladium-catalyzed arylations of functionalized 3-bromo-4-arylcoumarins also participated in the second arylation to give functionalized 3,4-diarylcoumarins
General and Efficient Route for the Synthesis of 3,4-Disubstituted Coumarins via Pd-Catalyzed Site-Selective Cross-Coupling Reactions
作者:Liang Zhang、Tianhao Meng、Renhua Fan、Jie Wu
DOI:10.1021/jo071117+
日期:2007.9.1
Palladium-catalyzed site-selective cross-couplingreactions of 3-bromo-4-trifloxycoumarin or 3-bromo-4-tosyloxycoumarin provide an efficient and facile route for the synthesis of 3,4-disubstituted coumarins, which include 3,4-diarylcoumarins, 3-amino-4-arylcoumarins, and 3-aryl-4-aminocoumarins. The order of reactivity of the (pseudo)halide substituents in the coumarins was found to be 4-OTf > 3-Br
A Pd-catalyzed alkyne and aryneannulation strategy via C–H activation has been implemented for the synthesis of π-extended coumarins. This synthetic strategy provides a wide range of π-extended coumarins in moderate to good yields with good functional group compatibility. Photophysical properties of the synthesized π-extended coumarins have been evaluated, and some of them show interesting fluorescent