Chiral Brønsted Acid-Catalyzed Intramolecular Asymmetric Allylic Alkylation of Indoles with Primary Alcohols

Herein,
chiral Brønsted acid-catalyzed intramolecular asymmetric
allylic alkylation of indoles with allylic primary alcohols is described.
The allyl alcohols were directly employed as the allylic precursors
in this metal-free protocol, without preactivation or any additional
activating reagents. This method provides the convenient synthesis
of a broad range of functionalized tetrahydrocarbazoles in excellent
yields (≤97%) with good enantioselectivity (≤93% ee).
The optimal conditions are compatible for gram-scale reaction.

本文详细介绍了手性布朗斯台德酸催化的吲哚分子内不对称烯丙基烷基化反应，其中烯丙基伯醇被直接用作烯丙基前体，在无需预活化或任何其他活化试剂的金属无催化体系中。该方法简便高效，能够在优异的产率（≤97%）和良好的对映选择性（≤93% ee）下合成多种功能化的四氢咔唑衍生物。在最佳条件下，该反应适用于克级规模的反应。