The Strecker reaction: kinetic and equilibrium studies of cyanide addition to iminium ions.

Kinetics studies are reported of the reactions of benzylidene benzylamine 4a, and of benzylidene allylamine 4b, with cyanide in aqueous buffers to give the corresponding [small alpha]-aminonitriles. The results allow the calculation of values of rate and equilibrium constants for reaction of the iminium ions formed from 4a and 4b with cyanide ions. These values are compared with those, obtained from the hydrolysis reactions, for reaction of the iminium ions with hydroxide ions and with water. Comparison with some other iminium ions reveals that those formed from 4a and 4b are relatively unreactive due to the possibilities of charge delocalisation.