Nucleophilic Addition of Enols and Enamines to α,β-Unsaturated Acyl Azoliums: Mechanistic Studies

1,4 but not 1,2! The reactivity of 1 towards different nucleophiles (deprotonated β‐diketones, enamines, and malonodinitrile) was investigated by NMR and kinetic experiments. These investigations proved that CC bond formation occurs by a Michael‐type 1,4‐addition and not by a 1,2‐addition and subsequent [3,3]‐sigmatropic rearrangement. The first X‐ray structure of an α,β‐unsaturated acyl azolium salt (1) is also presented.