Iridium-Catalyzed Regio- and Enantioselective C7-Allylic Alkylation of 4‑Aminoindoles

The first iridium-catalyzed direct intermolecular indole
C7-allylic
alkylation of 4-aminoindoles and racemic branched allylic esters was
reported. Various substituted substrates were applicable to give the
corresponding C7-allylated products in moderate to high yields (43–80%)
with high regio- and enantioselectivities (82–99% ee) under
mild reaction conditions. Representative transformations of the vinyl
group in the product were carried out to examine the utility of this
protocol.

本研究首次报道了铱催化4-氨基吲哚类化合物与外消旋支链烯丙基酯的直接分子间吲哚C7位烯丙基烷基化反应。在温和反应条件下，多种取代底物均可适用于该反应，以43%~80%的中等至较高产率得到对应的C7位烯丙基化产物，且产物具有较高的区域选择性与对映选择性，其对映体过量值（enantiomeric excess, ee）为82%~99%。此外，针对产物中乙烯基基团的代表性转化实验得以开展，以验证该催化方案的应用价值。