Allenes as the π-Component in Electrocyclization Reactions: Transformation of 1,3,4-Pentatrienyl Azomethine Ylides into Seven-Membered Heterocycles
作者:Karin Knobloch、Wolfgang Eberbach
DOI:10.1002/1099-0690(200207)2002:13<2054::aid-ejoc2054>3.0.co;2-m
日期:2002.7
the annulated methylene pyridoazepines 10a−c are formed. The reaction pathway includes base-catalysed propargyl-allene isomerization and dipole formation as the first steps followed by the ring closure of [9] to 10. The latter process represents the first example of the participation of an allene unit in 1,7-electrocyclization reactions of extended azomethine ylides. (© Wiley-VCH Verlag GmbH, 69451
在用碱处理通过吡啶 7 与烯丙基溴 6 季铵化获得的溴化吡啶鎓 8a-c 后,形成环状亚甲基吡啶并氮杂 10a-c。反应途径包括碱催化的炔丙基-丙二烯异构化和偶极子形成作为第一步,然后是 [9] 至 10 的闭环。后一过程代表了丙二烯单元参与 1,7-电环化的第一个例子扩展的偶氮甲碱叶立德的反应。(© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)