Rh(III)-catalyzed selective C2 C-H acyloxylation of indoles.

Herein, we present the first highly regio- and chemoselective C2 C-H acyloxylation of indole under rhodium catalysis and an N-quinolinyl auxiliary. This strategy accommodates a wide range of indoles and structurally diverse carboxylic acids with good reaction efficiencies to yield functionalized indoles. The utility of this logic was demonstrated by the concise synthesis of the functionalized 2-oxindole derivatives. Preliminary mechanistic studies indicate that catalyst turnover of RhIII-RhIV/V-RhII/III-RhIII might be involved in this catalytic C-H transformation.