Gold-Catalyzed Synthesis of Furans and Furanones from Sulfur Ylides
作者:Xueliang Huang、Bo Peng、Marco Luparia、Luis F. R. Gomes、Luís F. Veiros、Nuno Maulide
DOI:10.1002/anie.201203637
日期:2012.8.27
A golden switch: Doubly stabilized sulfonium ylides can be coupled with alkynes in a gold‐catalyzed synthesis of heterocycles. This method hinges on a switch in the reactivity of the sulfur ylide resulting from the simple modification of the electron‐withdrawing moieties and leads to either furans or furanones bearing a quaternary center (see scheme).
2,3,4- or 2,3,5-Trisubstituted Furans: Catalyst-Controlled Highly Regioselective Ring-Opening Cycloisomerization Reaction of Cyclopropenyl Ketones
作者:Shengming Ma、Junliang Zhang
DOI:10.1021/ja036616g
日期:2003.10.1
furans were highlyregioselectively formed from the cycloisomerizationreaction of the same starting cyclopropenes 1 via the subtle choice of the transition metal halides. Under the catalysis of 5 mol % PdCl2(CH3CN)2, 2,3,5-trisubstituted furans 2 were given in 50-88% yields with 95-99% regioselectivities, while 2,3,4-trisubstituted furans 3 were formed in 78-96% yields with 99% regioselectivities under