Multitasking rhodium-catalyzed remote C(sp3)–H functionalization reactions of acyclic dienes to yield benzene-fused heterocycles†

Remote C(sp³)–H bond functionalization reactions are environmentally benign methods for not only acyclic molecules but also cyclic molecules. However, products in previous reports have been limited to aliphatic five-membered ring structures. Herein, we developed an unprecedented multitasking rhodium-catalyzed reaction that can synthesize benzene-fused heterocyclic compounds, 2,3-disubstituted dihydrobenzofurans, through a remote C(sp³)–H bond functionalization reaction (chain-walking/cycloisomerization/hydroboration reaction). This catalytic system promotes a twice-occurring chain-walking/functionalization set in one pot, thus allowing the synthesis of dihydrobenzofurans with various side chain lengths at the 2- and 3-positions.