Rhodium(III)-Catalyzed Redox-Neutral C-H Activation/Annulation of N-Aryloxyacetamides with Alkynyloxiranes: Synthesis of Highly Functionalized 2,3-Dihydrobenzofurans

Alkynyloxiranes have been employed for the first time as effective coupling partners in Cp*Rh-III-catalyzed C-H functionalization reactions. Their annulation with N-aryloxyamides then offers a redox-neutral and efficient synthesis of functionalized 2,3-dihydrobenzofurans bearing an exocyclic E-allylic alcohol and a tetrasubstituted carbon center in good yields with a broad substrate scope. The products can be easily converted to molecules with more complexity, which provides an opportunity for rapid assembly of structurally diverse heterocycles.