Dearomative (4 + 3) Cycloaddition Reactions of 3-Alkenylindoles and 3-Alkenylpyrroles to Afford Cyclohepta[<i>b</i>]indoles and Cyclohepta[<i>b</i>]pyrroles
作者:Ferdinand Taenzler、Jiasu Xu、Sudhakar Athe、Viresh H. Rawal
DOI:10.1021/acs.orglett.2c02983
日期:2022.11.11
The dearomative (4 + 3) cycloaddition reactions of 3-alkenylindoles with in situ-generated oxyallyl cations furnish cyclohepta[b]indoles, functionality-rich frameworks found in many bioactive compounds, including all pentacyclic ambiguine alkaloids. The analogous reactions between oxyallyl cations and 3-alkenylpyrroles afford cyclohepta[b]pyrroles. The cycloadducts are generally formed in good to high
3-烯基吲哚与原位生成的氧烯丙基阳离子的脱芳香 (4 + 3) 环加成反应提供了环庚[ b ]吲哚,这是在许多生物活性化合物(包括所有五环模糊生物碱)中发现的功能丰富的框架。氧烯丙基阳离子和3-烯基吡咯之间的类似反应得到环庚[ b ]吡咯。环加合物通常以良好至高的产率和非对映选择性形成,并且可以容易地转化为有用的衍生物。此外,我们报告了使用亚胺二磷酸酯催化剂对脱芳族 (4 + 3) 环加成的对映选择性催化的初步研究。