Enantioselective Friedel–Crafts alkylation for synthesis of 2-substituted indole derivatives.

An efficient catalytic asymmetric intermolecular C2 Friedel–Crafts alkylation reaction between N-methyl skatole and β,γ-unsaturated α-ketoesters has been realized by a chiral N,N′-dioxide-Ni(ii) complex. The corresponding indole derivatives were obtained in good yield (up to 96%) with excellent enantioselectivities (up to 99% ee) under mild reaction conditions. [ABSTRACT FROM AUTHOR]