Activated Aminocarbene Complexes of the Fischer Type: Synthesis, Structure, and Annelation Reactions

of N ‐terminal acyl or Boc functions allows activation of aminocarbene complexes such as 1 —even at room temperature, CO is lost and five‐membered ring acylaminocarbene chelate complexes such as 2 are formed. These complexes can be annelated by alkynes under mild conditions to give five‐membered (e.g., 3 ) and six‐membered ring compounds.