Enantiopure Trans-4,5-Disubstituted 2-Imidazolidinones via Copper(I)-Catalyzed Ring Opening of 1,1'-DiBoc-2,2'-Biaziridine with Grignard Reagents.

The copper-catalyzed ring opening of chiral-pool-derived 1,1'-diBoc-2,2'-biaziridine with Grignard reagents affords enantiopure 2-imidazolidinones in a desymmetrizing, cascade process involving the Boc protecting group. This divergent strategy provides reaction-ready, N-differentiated products and allows two C-C bond constructions concurrent to imidazolidinone formation. A variety of alkyl, cyclic, and aryl Grignard reagents are tolerated in reasonable to good yields.