An Entry to the Azocino[4,3-<i>b</i>]indole Framework through a Dehydrogenative Activation of 1,2,3,4-Tetrahydrocarbazoles Mediated by DDQ: Formal Synthesis of (±)-Uleine
作者:Süleyman Patir、Erkan Ertürk
DOI:10.1021/jo1021663
日期:2011.1.7
It is presented that hexahydro-1,5-methano[4,3-b]indoles were efficiently synthesized in high yields (up to 89% yield) through the cyclization reaction of starting tetrahydrocarbazoles bearing a monoalkylaminocarbonylmethyl moiety at the C-2 position mediated by 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). A mechanistic proposal is also given that mainly includes two cascade reactions: (i) formation
结果表明,通过在C-2位介导的具有单烷基氨基羰基甲基部分的起始四氢咔唑的环化反应,可以高收率(高达89%的收率)有效地合成六氢-1,5-甲基[4,3- b ]吲哚。 2,3-二氯-5,6-二氰基苯并醌(DDQ)。一种机械的提案也考虑到主要包括两个级联反应:(ⅰ)通过的四氢咔唑功能和(ii)DDQ介导的脱氢形成插烯亚胺阳离子的帧内-分子和合成选择性地将酰胺官能团作为亲核试剂添加到乙烯基亚胺基阳离子上。此外,该环化反应已成功地用于(±)-精氨酸(一种Asperspermatan骨架型生物碱)的正式全合成中。