Synthesis of 5-Aminooxazoles and Zwitterionic Fused Imidazolones by I2-Mediated C-H Amination.

Iodine-mediated C-H amination reactions of β-ketoamides with alkylamines have been developed under transition-metal-free conditions. In the presence of Na2CO3 as the base, I2-promoted annulation of β-ketoamides with benzylamines produces 5-aminooxazole derivatives. Replacement of arylmethylamines with tetrahydroisoquinolines leads to the formation of novel zwitterionic fused imidazolone products. The synthetic protocols are operationally simple and can be conveniently conducted on a gram scale.