Kinetics of carbenium ion additions to methylenecycloalkanes: Cycloalkyl cation stabilities are not predominantly controlled by strain

Article abstract of DOI:10.1021/jo00080a027

Kinetic investigations of the reactions of the (p-anisyl)phenylcarbenium tetrachloroborate (1 BCl₄^-) with methylenecycloalkanes (ring size 3-12 and 15) have been performed. The second-order rate constants correlate with the solvolysis rates of the corresponding cycloalkyl derivatives, though none of the ring carbons is rehybridized in the rate-determining step (electrophilic attack of 1 at the CC double bond). A simple explanation for the observed rate effects cannot be given, and it is claimed that the common rationalization of cycloalkyl solvolysis rates by differences of internal strain has to be modified.