Synthesis of hexahydropyrrolo[2,3-b]indole alkaloids based on the aza-Pauson-Khand-type reaction of alkynecarbodiimides.
Synthesis of hexahydropyrrolo[2,3-b]indole alkaloids based on the aza-Pauson-Khand-type reaction of alkynecarbodiimides.
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DOI：
10.1021/jo071137b
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发表时间：
2007-08
期刊：
影响因子：
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通讯作者：
Daisuke Aburano;T. Yoshida;N. Miyakoshi;C. Mukai
中科院分区：
文献类型：
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作者：
Daisuke Aburano;T. Yoshida;N. Miyakoshi;C. Mukai
用30 mol %的Co2(8)和30 mol %的TMTU在70℃的甲苯中处理后，苯桥接的烷基糖二亚胺发生了有效的闭合环反应，得到了产率很高的吡咯[2,3-b]吲哚-2- 1。这些条件几乎可以抑制尿素衍生物的生成，当苯中Co2（CO）浓度为10 mol %和TMTU浓度为60 mol %时，这一结果是一致的。以NaBH(4)/烷基溴处理为关键步骤，在C(3a)-位置引入角取代基，合成了8个六羟基吡咯[2,3-b]吲哚生物碱。
Upon treatment with 30 mol % of Co2(CO)(8) and 30 mol % of TMTU in toluene at 70 degrees C, benzene-bridged alkynecarbodiimides efficiently underwent a ring-closing reaction to give the pyrrolo[2,3-b]indol-2-ones in good yields. These conditions could nearly suppress the formation of the urea derivatives, which were consistently observed when 10 mol % of Co2(CO)(8) and 60 mol % of TMTU in benzene were used. The synthesis of the eight hexahydropyrrolo[2,3-b]indole alkaloids was accomplished from the resulting pyrrolo[2,3-b]indol-2-ones via the introduction of an angular substituent at the C(3a)-position by treatment with NaBH(4)/alkyl bromide as the crucial step.