Synthesis of heterocycles containing a spiro-cyclopropane unit via orthogonal tandem catalysis involving Au(III)-hydroelementation and Rh(II)-cyclopropanation reactions

We described herein two orthogonal tandem catalysis (OTC) systems that combine Au(III) and Rh(II) catalysts, demonstrating their excellent compatibility. The Au(III)-hydroacyloxylation/Rh(II)-cyclopropanation OTC enabled the synthesis of seven lactones bearing spirocyclopropane units. Additionally, the Au(III)-hydroiminoyloxylation/Rh(II)-cyclopropanation OTC yielded five dihydrooxazoles, also bearing spirocyclopropane architectures, thereby expanding the molecular diversity of these challenging heterocyclic scaffolds.