Rh(III)-Catalyzed [3 + 2] Spirocyclization of 2H-Imidazoles with 1,3-Diynes for the Synthesis of Spiro-[imidazole-indene] Derivatives.

An effective strategy to synthesize spirocyclic compounds, [imidazole-4,1'-indene], has been efficaciously developed relied on Rh(III)-catalyzed [3 + 2] spirocyclization of 2H-imidazoles and 1,3-diynes with excellent chemselectivity and regioselectivity. This protocol shows a straightforward way to construct the versatile spirocyclic compounds with wide functional group compatibility, high atom economy, and diverse functionalization of products.