DMSO/t-BuONa/O2-Mediated Aerobic Dehydrogenation of Saturated N-Heterocycles
Aromatic N-heterocycles such as quinolines, isoquinolines, and indolines are synthesized via sodium tert-butoxide-promoted oxidative dehydrogenation of the saturated heterocycles in DMSO solution. This reaction proceeds under mild reaction conditions and has a good functional group tolerance. Mechanistic studies suggest a radical pathway involving hydrogen abstraction of dimsyl radicals from the N-H bond or α-C-H of the substrates and subsequent oxidation of the nitrogen or α-aminoalkyl radicals.
From Anilines to Quinolines: Iodide- and Silver-Mediated Aerobic Double C?H Oxidative Annulation–Aromatization
Quinoline synthesis from easily accessible raw materials such as anilines is a valuable and meaningful task. Herein, we communicate an iodide- and silver-mediated C?H/C?H oxidative annulation–aromatization between anilines and allyl alcohols. This protocol provides a direct route to the synthesis of quinoline derivatives from inexpensive commodities. Various kinds of anilines, even heterocyclic anilines, were shown to be workable substrates, generating the corresponding multi-substituted quinolines in good yields.