Ruthenium-Catalyzed Heteroatom-Directed Regioselective C-H Arylation of Indoles Using a Removable Tether

A new approach to C-2 arylated indoles has been developed by utilizing a ruthenium-catalyzed, heteroatom-directed regioselective C-H arylation. The reaction is highly site-selective and results in very good yields. The highlight of the work is the use of a removable directing group and compatibility of the catalytic system with halogen functional groups in the substrates.