Electrophilic Reactivity of the (Phenyl)Cr(CO)3-Substituted α-Propargyl Cation

The reactivity of the (phenyl)Cr(CO)3-substituted α-propargyl cation 2 was quantified by measuring the kinetics of nucleophilic trapping reactions. In comparison to related dicobalthexacarbonyl alkynyl substituted carbenium ions the electrophilicity E of 2 is by 2.5 orders of magnitude larger and, thus, this species is more reactive.