Spiro[indene-1,4′-oxa-zolidinones] Synthesis via Rh(III)-Catalyzed Coupling of 4‑Phenyl-1,3-oxazol-2(3H)‑ones with Alkynes: A Redox-Neutral Approach

Transition-metal-catalyzed C–H activation synthesis of heterocyclic spiro­[4,4]­nonanes has persistently witnessed the use of additional stoichiometric transition-metal oxidant when employing CC bond as the spiro ring closure site. Herein, we have addressed the issue by reporting a redox-neutral strategy for spiro­[indene-1,4′-oxa-zolidinones] synthesis via Rh­(III)-catalyzed coupling of 4-phenyl-1,3-oxazol-2­(3H)-ones with alkynes. The synthesis features a broad substrate scope and high regiospecificity.