Enantioselective Intramolecular Benzylic C-H Amination Enabled by Nonheme Iron Catalysis

The development of asymmetric C(sp³)-H amination methodologies employing earth-abundant metal catalysts is a significant goal in synthetic chemistry. Drawing inspiration from the high selectivity of heme and nonheme iron enzymes in catalyzing C(sp³)-H amination reactions, in this study, we describe an efficient and sustainable strategy for constructing chiral imidazolidin-2-ones. This process utilizes a readily accessible nonheme iron complex bearing a chiral tetradentate aminopyridine ligand with an octahydro-1,1'-biisoquinoline backbone as the catalyst. Under mild conditions, the catalyst enables an enantioselective intramolecular C(sp³)-H amination of N-aroyloxy ureas to afford the target chiral heterocycles. The absolute configuration of the synthesized imidazolidin-2-ones was unambiguously confirmed by X-ray diffraction analysis.