Copper(I)-Catalyzed α,β-Dehydrogenative\n[2 + 3] Heteroannulation of Saturated Amines with Diaziridinone via\nHydrogen Atom Transfer

The\nsite-selective functionalization of carbon(sp<sup>3</sup>)–hydrogen\nbonds in saturated amines remains a persistent challenge owing to\ntheir intrinsic electronic deficiency, particularly in activating\nthe α and β positions simultaneously for annulation reactions.\nHerein, we report a copper(I)-catalyzed dehydrogenation and [2 + 3]\ncycloaddition of commercially available amines with diaziridinone,\nwhich facilitated the direct synthesis of highly valuable imidazolidone\nderivatives. Operationally simple methodology has a broad substrate\nscope and convenient scalability, providing an effective and complementary\nplatform for the rapid incorporation of <i>N</i>-heterocycles\ninto amine molecules. Furthermore, comprehensive mechanistic investigations\nand computational studies indicated the pathway of the radical-type\nhydrogen atom transfer and [2 + 3] cycloaddition, which were promoted\nby a four-membered copper(III) species.