Tricarbonylcyclohexadienyliumiron Complexes in the Synthesis of 2-Azaspiro[5.5]undecane System with Tunable Amide.

Excellent regio- and stereoselectivity during nitrile addition to dienylium-Fe(CO)(3) can be achieved with perchlorate salts, allowing the preparation of the 1-oxo- and 3-oxo-2-azaspiro[5.5]undecane ring systems. The phthalimide complex 2 was prepared in high yield by Mitsunobo reaction.