Benzofurans as Efficient Dienophiles in Normal Electron Demand [4 + 2] Cycloadditions
作者:Nathalie Chopin、Hélène Gérard、Isabelle Chataigner、Serge R. Piettre
DOI:10.1021/jo802205d
日期:2009.2.6
arising from the reaction have been shown to depend on different factors among which the type of the electron-withdrawing substituent of the benzofuran, the nature of the reacting diene, and the method of activation. In the presence of all-carbon dienes, the reaction yields the expected Diels−Alder adducts. When thermal activation is insufficient, a biactivation associating zinc chloride catalysis and