Influence of Protonation on Gattermann-Koch Formylation Rate of Alkylbenzene in CF3SO3H-SbF5

Article abstract of DOI:10.1021/jo00112a035

The influence of the protonation on Gattermann-Koch formylation rate of alkylbenzenes was studied in CF3SO3H-SbF5.From the kinetic study of m-xylene formylation using various SbF5:m-xylene molar ratios in CF3SO3H, it is revealed that the formylation rate is explained with the equations which take into account the protonation equilibrium of m-xylene, and the apparent formylation rate is decreased by the protonation.The decrease of the apparent formylation rate by the protonation is proportional to the ratio of protonated alkylbenzene to form the ?-complex; therefore, the apparent relative formylation rate of alkylbenzenes is not consistent with their relative basicity under strong acidic conditions such as in CF3SO3H-SbF5.