Interpretation of the Relationship between Reactivity and Selectivity

Mechanistic Interpretation of the Relationship between Reactivity and Selectivity 

Isotope effects provide insight into other aspects of the mechanisms of individual electrophilic aromatic substitution reactions. In particular, since primary isotope effects are expected only when the deprotonation of the a complex to product is rate determining, the observation of a substantial k /k points to a rate-determining 

Later transtion state with substantial a bond formation 

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