Two Efficient Cascade Reactions to Synthesize Substituted Furocoumarins
摘要:
We have developed two efficient one-pot reactions to generate furo[3,2-c]coumarins and chlorofuro[3,2-c]coumarins through addition/cyclization/oxidation and chlorination. One cascade addition/cyclization/oxidation sequence of 1 with H2O in the presence of 20% CuCl as Lewis acid under an air atmosphere generated the 2-substituted-4H-furo[3,2-c]chromen-4-one 2. Another sequence in the presence of 10% CuBr and excess CuCl2 as the oxidant afforded the 3-chloro2-substituted-4H-furo[3,2-c]chromen-4-one 3.
A novel multicomponent reaction to synthesize substituted furo[3,2-c]chromenes via a Pd-catalyzed cascade process
作者:Lizhi Zhao、Gang Cheng、Youhong Hu
DOI:10.1016/j.tetlet.2008.10.025
日期:2008.12
A novel one-pot three-component reaction for the synthesis of multisubstituted furo[3,2-c]chromenes using 3-(1-alkynyl)chromones, aryl iodides, and alcohols is developed via Pd-catalyzed cascade 1,4-addition and cyclization. This synthetic approach efficiently generates two C–O bonds and one C–Cbond to construct diverse furo[3,2-c]chromenes structures.
通过钯催化的级联1,4-加成反应,开发了一种新颖的一锅三组分反应,该反应可使用3-(1-炔基)色酮,碘代芳基和醇类合成多取代的呋喃并[3,2- c ]色烯。和环化。这种合成方法可以有效地产生两个C–O键和一个C–C键,以构建不同的呋喃[3,2- c ]苯二甲基结构。
C-Alkynylation of Chromones by Sonogashira Reaction
作者:Tamás Patonay、István Pazurik、Anita Ábrahám
DOI:10.1071/ch13006
日期:——
Sonogashira reaction of bromochromones and -flavones with a bromine atom on their benzene or heterocyclic ring with various terminal alkynes gave the desired products with nearly the same efficiency as the previously used iodine derivatives. The coupling reactions were performed in the presence of [tetrakis(triphenylphosphine)palladium(0)], copper(i) co-catalyst, and triethylamine, resulting in the