Reactivity of Chlorotrifluoromethylcarbene: Activation Parameters for Halocarbene–Alkene Addition Reactions

Activation parameters are reported for ClCCF3 additions to three alkenes (tetramethylethylene, cyclohexene, and 1-hexene). The results are compared to those for CCl2, CClF, and CF2. Activation enthalpies decrease as the carbene stability decreases and its electrophilicity increases, and also as alkene reactivity (degree of alkylation) increases. Activation entropies decrease in parallel with activation enthalpies, suggesting the operation of enthalpy–entropy compensation in these carbene additions.