作者:Yoshihiko Ito、Kazuhiro Kobayashi、Norihiko Seko、Takeo Saegusa
DOI:10.1246/bcsj.57.73
日期:1984.1
New indole synthesis starting with o-methylphenyl isocyanides such as o-tolyl, 2,4-xylyl, and 2,6-xylyl isocyanide is described in full detail. Treatment of o-tolyl isocyanide with LDA in diglyme at −78 °C generated selectively o-(lithiomethyl)phenyl isocyanide in an almost quantitative yield, which on warming up to room temperature was cyclized to indole after aqueous workup. Similary, 2,4-xylyl and
以邻甲基苯基异氰化物(例如邻甲苯基、2,4-二甲苯基和 2,6-二甲苯基异氰化物)为起始原料的新型吲哚合成得到了详细描述。在-78°C 下,在二甘醇二甲醚中用 LDA 处理邻甲苯基异氰化物,选择性地以几乎定量的产率生成邻(硫代甲基)苯基异氰化物,其在升温至室温后在水性处理后环化为吲哚。类似地,2,4-二甲苯基和2,6-二甲苯基异氰化物定量环化为5-甲基吲哚和7-甲基吲哚。邻(锂硫甲基)苯基异氰化物与诸如卤代烷和环氧烷之类的亲电子试剂反应得到邻烷基苯基异氰化物,其通过在邻苄基碳上的锂化而环化得到3-取代的吲哚。另一方面,在-78°C 下原位生成的邻(锂硫甲基)苯基异氰化物首先升温至室温,然后用亲电试剂处理以提供 1-取代的吲哚。邻(锂硫甲基)苯基异氰化物以相当好的收率与 N-酰基...