钯介导的δ-吲哚基-α,β-不饱和化合物的氧化环化对环戊二烯[ b ]吲哚的合成和非均相加氢以生成熔融二氢吲哚
摘要:
环戊[ b ]吲哚部分代表几种天然和合成化合物的关键骨架单元,这些化合物表现出多种生物学特性。我们在本文中描述了用于合成具有巨大结构多样性的环戊并[ b ]吲哚的两步序列,总产率高达37%。关键步骤是钯催化的3-烷基吲哚的氧化环化反应(藤原-莫里塔尼反应)。所获得的环戊[ b ]吲哚被用作非均相氢化反应的底物,从而以中等收率提供了新的熔融二氢吲哚。三个这样的二氢吲哚的酸催化的分子内环化反应以89%,90%和61%的收率得到四环内酰胺。
Synthesis of 3,4-bridged indoles by photocyclisation reactions. Part 2. Photocyclisation of halogenoacetyl tryptophol derivatives and α-chloro indol-3-ylalkanoate esters
摘要:
Irradiation of the trichloroacetates 2, 4 and 5, derived from the corresponding tryptophols, in methanolic acetonitrile results in photocyclisation to the indole 4-position, and the formation of the pyrrolobenzoxocines 9-11. Attempted photocyclisation of the 'reversed' alpha-chloro esters 15a, 15b and 18 was thwarted by readily occurring elimination of HCl, although the dimethyl compound 15c did cyclise to give the cycloheptaindole 20 upon irradiation in acetonitrile.