Chlorotrimethylsilane: A Powerful Lewis Acidic Catalyst in Michael‐Type Friedel–Crafts Reactions of Indoles and Enones

Abstract

Catalytic amount of chlorotrimethylsilane (TMSCl) was found to be an effective silicon Lewis acid catalyst in catalyzing the Michael‐type Friedel–Crafts reactions of indoles and chalcones to afford corresponding 3‐substituted indole derivatives in good to excellent yields. The method is metal‐free, has mild reaction conditions, and generates good yields of products with greater selectivity, which make it a useful and attractive process for the synthesis of different indole derivatives.

Keywords:

• dual activation
• enone
• Friedel–Crafts reaction
• indole
• silane

Acknowledgments

This work was supported by the National Nature Science Foundation of China (Project No. 20572114). Xu L. W. is greatly indebted to Jacques Mortier and Anne‐Sophie Castanet, CNRS and Université du Maine, Unité de chimie organique moléculaire et macromoléculaire (UMR 6011), Faculté des sciences, for their help.