Saccharide-accelerated hydrolysis of boronic acid imines

Twenty substituted N-benzylidineaniline derivatives have been synthesised and their kinetic behaviour investigated. The rate of hydrolysis of the boronic acid imines was found to be accelerated by added saccharide. Catalytic activity was only observed below the pK(a) of the boronic acid. Altering the concentration or type of saccharide revealed a Bronsted-like linear free energy relationship, indicating that intramolecular general acid catalysis was operating. Structure activity relationship studies demonstrated that the system's electronic demands were independent of the boronic acid moiety.