Divergent Synthesis of Di‐ and Mono‐Alkylated Indoles via Tunable Iron‐Catalyzed Hydroarylation of Styrenes

Abstract We report an iron‐catalyzed divergent synthesis of alkylated indoles based on precise control of the activation sites on indoles through the selection of catalysts. Using indoles and styrenes as starting materials, 3,5‐ di ‐alkylated indoles could be prepared selectively and directly for the first time by treating with a catalytic amount of Fe(OTf) 3 and 3‐alkylated indoles were achieved exclusively by adding a catalytic amount of γ ‐cyclodextrin as the cocatalyst with Fe(OTf) 3 . This simple method was demonstrated with 52 examples with high yields and broad functional group compatibilities.