Rh(III)‐Catalyzed Cascade [3+3] Spiroannulation of N‐Acyl Ketimines with Iodonium Ylides: Access to Spiro‐N,O‐Ketals

A Rh(III)‐catalyzed cascade C‐H activation/[3+3]spiroannulation of 3‐hydroxy‐3‐arylisoindolin‐1‐ones with iodonium ylides has been developed. The method facilitates the efficient and selective construction of spirocyclic compounds in a one‐pot manner, offering high yields and excellent conversion. The reaction proceeds via a highly regioselective process, resulting in the formation of spiro‐N,O‐ketals with remarkable chemo‐ and stereoselectivity. This strategy provides a valuable protocol for the synthesis of complex spirocyclics with potential applications in medicinal chemistry and materials science.