Cyanide abstractions from benzyl isocyanides by Tri-n-Butyltin radical: An implication of imbalanced transition state and entropy control of reactivities

Article abstract of DOI:10.1016/S0040-4039(97)01185-4

The relative rates and Hammett constants (ρ = 0.70) are immune from the temperature effects thus violating reactivity/selectivity principle. The polar TS can be classified as the 'imbalanced TS'. The substituents control the extent of the bond fissions end the rates are governed by the entropy term.