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.