Wulff–Dötz reaction

[11] The mechanism is thought to begin with the loss of carbon monoxide from the Fischer carbene complex 1 to give intermediate 3.

The loss of CO is rate limiting making the investigation of this reaction mechanism difficult, since all subsequent steps occur rapidly.

When R1 is hydrogen, intermediate 6 is short lived and proceeds to the metal tricarbonyl arene complex 2.

Exposing Fischer carbene with alkenyl side chain to an alkyne gives a highly substituted phenol.

[13] The half-sandwich complex in the Dötz reaction can be demetallated to give corresponding aryl product, or it could be further employed for a nucleophilic addition to aromatic system strategy for synthesis of fully-substituted benzene ring.

If the alkyne partner bearing a ketone substituent and both R and R’ are not bulky enough, a favored conformation for an 8e pi cyclization could be dominant leading to a fused bicyclic lactone system.

Fischer carbenes with an α-hydrogen could form could give cyclopentenone product similar to Pauson-Khand reaction.