their catalytic potential in acylation reactions of alcohols. The ability of the substitution pattern to stabilize acylpyridinium cations, which act as critical intermediates in the catalytic cycle of pyridine-catalyzed acylation reactions, has been assessed at the MP2(FC)/6-31+G(2d,p)//B98/6-31G(d) level of theory and inclusion of solvent effects in chloroform using the PCM continuum solvation model