Synthesis of Tetrahydro[1,3,4]triazepines via Redox-Neutral α-C(sp)-H Amination of Cyclic Amines.

A Brønsted acid-catalyzed α-C(sp)-H amination of cyclic amines using hydrazines as coupling partners has been reported. This methodology provides a unique protocol to the one-step assembly of tetrahydro[1,3,4]triazepines via [1,5]-hydride transfer-initiated C(sp)-H amination. This reaction features mild conditions, good yields, and high atom economy.