Selective sp 3 C–H Bond Activation Based on a Carbocation Relay: Friedel–Crafts Reaction with Alkanes as the Alkylating Component

A highly efficient and selective intramolecular Friedel–Crafts reaction of 3‐methylbutyl or 4‐methylpentyl‐substituted aromatics has been developed using a carbocation relay strategy through selective sp 3 C–H bond activation, providing a facile and cost‐effective approach for the construction of benzocyclic compounds. A variety of 1,1‐dimethylindane and naphthalene derivatives have been prepared from very simple starting materials in good yields with high selectivity. The present strategy has provided a new example of a Friedel–Crafts reaction with alkanes as the alkylating component and constitutes a convenient approach to selective C–H bond activation and functionalization of alkane derivatives.