Tunable Rh(III)-Catalyzed C(sp 2 )-H Bond Functionalization of Aryl Imidates with Cyclic 1,3-Diones: Strategic Use of Directing Groups.

A tunable Rh(III)-catalyzed C(sp 2 )-H bond functionalization of aryl imidates with cyclic 1,3-diones was developed. With suitable and straightforward reaction condition adjustments, the C-H bond functionalization of diverse aryl imidates with cyclic 1,3-diones occurred smoothly and precisely at room temperature. Accompanied by different directing group transformations, a series of corresponding aryl nitriles, hydrophenanthridin-1(2 H )-ones, spiro isoindoles, or hydrophenanthridine-1,6(2 H ,5 H )-diones were synthesized in good yields to provide a rational directing group utilization strategy for the Rh(III)-catalyzed C(sp 2 )-H bond activation. Control experiments and primary mechanistic studies revealed that solvent effects and functional group electronic effects might influence the reaction's selectivity.