Exchange reactions of adducts of nitrogen donors with boron halides

Abstract

The exchange reactions of the adducts of NN-dimethyl-o-toluidine with boron trichloride and with phenylboron dichloride (2) and of NN-dimethylaniline with phenylboron dichloride (3) have been examined by an n.m.r. technique. The results are similar to those obtained previously for the adducts of NN-dimethyl-p-chloroaniline (4) and NN-dimethylaniline (5) with boron trichloride. The rate-determining step in amine exchange is usually a unimolecular ionisation of the adduct but adducts (1), (2), and (3) show equilibrium ionisation an order of magnitude greater than do (4) and (5).