Rhodium III -catalyzed remote difunctionalization of arenes assisted by a relay directing group.

Rhodium-catalyzed diverse tandem twofold C-H bond activation reactions of para -olefin-tethered arenes have been realized, with unsaturated reagents such as internal alkynes, dioxazolones, and isocyanates being the coupling partner as well as a relay directing group which triggers cyclization of the para -olefin group under oxidative or redox-neutral conditions. The reaction proceeded via initial ortho -C-H activation assisted by a built-in directing group in the arene, and the ortho -incorporation of the unsaturated coupling partner simultaneously generated a relay directing group that allows sequential C-H activation at the meta -position and subsequent cyclization of the para -olefins. The overall reaction represents C-C or N-C difunctionalization of the arene with the generation of diverse 2,3-dihydrobenzofuran platforms. The catalytic system proceeded with good efficiency, simple reaction conditions, and broad substrate scope. The diverse transformations of the products demonstrated the synthetic utility of this tandem reaction.