Photoinduced EDA Complexes Enabled C3 (Hetero)arylation of Indoles Using Amine as a Transient Occupying Group

Herein, an EDA complex enabled selective C3 (hetero)arylation of indole was established, utilizing morpholine as the transient occupying group. This protocol is efficient, sustainable, and exhibits excellent substrate compatibility and functional group tolerance. Mechanistic studies revealed the binding of morpholine to the C2 position of the indole cation radical plays a key role in forming the transient radical at the C3 position. Furthermore, late-stage functionalization of biorelevant compounds and gram-scale synthesis demonstrate the utility of this protocol.