Silver-Catalyzed Formal [3+3] Heteroannulation of Aziridines with 3-Aminoacrylates via Ring-Opening and C-H Amination: Access to 1,4,5,6-Tetrahydropyrazines

Direct construction of the piperazine scaffolds with multiple functionalities remains important yet challenging. Herein, a silver-catalyzed formal [3 + 3] heteroannulation of aziridines with 3-aminoacrylates via ring-opening and vinyl C(sp2)-H amination for the direct synthesis of tetrasubstituted 1,4,5,6-tetrahydropyrazines is reported. Upon the catalytic activation of the silver Lewis acid, this protocol enables the formation of two new C-N bonds through selective nucleophilic ring-opening and C-H aminative cyclization cascades, featuring a broad substrate scope and a good functional group tolerance with excellent selectivity.