Scheme 3. Divergent syntheses of 5 pyrroloiminoquinone natural products from key tricyclic intermediate 21. (A) Selective functionalization of the 2° aniline nitrogen. (B) Selective functionalization of the indole nitrogen. (C) Selective functionalization of the 1° aniline nitrogen. (D) Selective functionalization of C14. (E) Selective functionalization of C20.
