Heterocycle–Heterocycle Strategies: (2-Nitrophenyl)isoxazole Precursors to 4‑Aminoquinolines, 1H‑Indoles, and Quinolin-4(1H)‑ones

Reductive heterocycle–heterocycle (heterocycle → heterocycle; H–H) transformations that give 4-aminoquinolines, 3-acylindoles, and quinolin-4(1H)-ones from 2-nitrophenyl substituted isoxazoles are reported. When this methodology is applied to 3,5-, 4,5-, and 3,4-bis(2-nitrophenyl)isoxazoles, chemoselective heterocyclization gives quinolin-4(1H)-ones, and 4-aminoquinolines, exclusively.