Nitrative Spirocyclization Mediated by TEMPO: Synthesis of Nitrated Spirocycles from N‐Arylpropiolamides,tert‐Butyl Nitrite and Water

A new method for the nitrative spirocyclization of alkynes is described. This method involves the oxidative difunctionalization of alkynes initiated by a radical attack pathway using t‐BuONO (tert‐butyl nitrite) combined with water as the nitro source and TEMPO (2,2,6,6‐tetramethyl‐piperidin‐1‐yl)oxyl] as the initiator, and it represents a new example of oxidative alkyne difunctionalization via the formation of C N/C C bonds for the assembly of nitroalkene unit‐containing spirocycles.