Synthesis of indolines by copper-mediated intramolecular aromatic C-h amination.

A Cu(OAc)2-mediated intramolecular aromatic C-H amination proceeds with the aid of a picolinamide-type bidentate coordination group to deliver the corresponding indolines in good yields. The reaction occurs smoothly even under noble-metal-free conditions, and in some cases the use of an MnO2 terminal oxidant renders the process catalytic in Cu. The mild oxidation aptitude of Cu(OAc)2 and/or MnO2 accommodates the formation of electron-rich thiophene- and indole-fused indoline analogues. The Cu-based system can provide an effective approach to various indolines of potent interest in pharmaceutical and medicinal chemistry.