Rhodium-Catalyzed Tandem C-H Annulation Enabled by Transient Directing Group Strategy and Sequential Nucleophilic Substitution.

A novel protocol of rhodium-catalyzed tandem C-H annulation of aldehyde and aniline with diazonaphthalen-1(2 H )-one via transient directing group strategy and sequential nucleophilic substitution has been demonstrated in moderate to excellent yields. This reaction proceeds smoothly via intramolecular cyclization to form 6 H -benzo[ c ]chromen-6-ol and is followed by nucleophilic substitution of para -carbon of aniline to construct 6-aryl-6 H -benzo[ c ]chromene derivatives. A series of 6-aryl-6 H -benzo[ c ]chromenes were synthesized in one-pot via the tandem C-H annulation.