Pyridine Activation via Copper(I)-Catalyzed Annulation toward Indolizines
作者:José Barluenga、Giacomo Lonzi、Lorena Riesgo、Luis A. López、Miguel Tomás
DOI:10.1021/ja106751t
日期:2010.9.29
cyclization of pyridines toward alkenyldiazoacetates leading to functionalized indolizine derivatives is reported. A broad range of pyridine derivatives (including quinoline and isoquinoline) is compatible with this cyclization reaction. The process represents the first successful example of metal-catalyzed cyclization of a π-deficient heterocyclic system with alkenyldiazo compounds.
A unique strategy toward the synthesis of polysubstituted indolizines has been developed. When 2-pyridinyl-2-(2′-bromoallyl)-1-carboxylates were treated with Cs2CO3, the starting material went through a methylenecyclopropane ring formation/opening cascade, and the corresponding indolizines were obtained in moderate to good yield as a single regioisomer.
已经开发了合成多取代的吲哚嗪的独特策略。当用Cs 2 CO 3处理2-吡啶基-2-(2'-溴烯丙基)-1-羧酸盐时,起始原料经过亚甲基环丙烷成环/开环级联反应,得到相应的吲哚嗪类化合物,收率中等至良好。一个单一的区域异构体。