On the mechanism of reaction between ketones and nitriles. Unexpected results from benzyl nitriles

Benzyl nitriles bearing electron donating groups react with ketones in the presence of trifluoromethanesulfonic anhydride to form naphthalene amines and related compounds. In contrast, the same benzyl nitriles substituted with electron withdrawing groups form the corresponding 2,4-dibenzyl substituted pyrimidines. A mechanism is proposed that explains the divergence in reaction paths leading to these products.