Copper-catalyzed construction of ( Z )-benzo[ cd ]indoles: stereoselective intramolecular trans -addition and S N -Ar reaction.

Substituted benzo[ cd ]indoles are one of the most attractive frameworks because of their wide range of biological and optical activities. Herein, a copper-catalyzed one-step synthesis of biologically important polysubstituted benzo[ cd ]indoles starting from 8-alkynyl-1-naphthylamine derivatives is reported. In this protocol, many substituents tolerated the reaction conditions and produced ( Z )-benzo[ cd ]indoles in good yields. Preliminary mechanistic studies indicated that the reaction proceeds via a stereoselective intramolecular trans -addition and S N -Ar reaction with high selectivity and high yields. The synthesized polysubstituted ( Z )-benzo[ cd ]indoles possess sulfonamide building blocks, which make them candidates for bioactive molecules.