Rhodium(II)‐Catalyzed Highly Stereoselective C3 Functionalization of Indolizines with N‐Sulfonyl‐1,2,3‐triazoles

An efficient and highly stereoselective approach for the C3 functionalization of indolizines through rhodium(II)‐catalyzed insertion of aza‐vinyl carbenes to synthesize N‐sulfonylamine alkenyl derivatives of indolizines is disclosed. Variably functionalized indolizines underwent C3 functionalization to afford moderate to good yields. Under similar reaction conditions pyrrolo[1,2‐a]quinolines resulted in regioselective C1 functionalization to give their N‐sulfonylamine alkenyl derivatives. The reaction methodology was successfully extended for the preparation of 1,3‐bis(N‐sulfonylamine alkenyl)indolizine derivatives and C3‐functionalized indolizines were used for the preparation of new molecular entities. A rhodium(II)‐catalyzed insertion of aza‐vinyl carbenes to indolizines led to a highly stereoselective synthesis of C3 substituted N‐sulfonylamine alkenyl derivatives of indolizines. The reaction offers an efficient route for functionalization of variably substituted indolizines and pyrrolo[1,2‐a]quinolines. The methodology also achieves a bis‐functionalization of indolizines.