An Addition Reaction of Diethylamine to Styrene Catalyzed by Lithium Diethylamide

An addition reaction of diethylamine to styrene catalyzed by lithium diethylamide was found to proceed stoichiometrically to produce 1-diethylamino-2-phenylethane. The rate of the reaction was expressed by the equations: υ=k[Styrene][Et2NLi]1.3 and υ=k[Styrene][Et2NLi], the ratios of [Et2NH]0 to [Et2NLi]0 being 3.0 and 10 respectivly. On the basis of the kinetic studies, the mechanism of the addition reaction was elucidated. The nucleophilic character of this reaction was clearly demonstrated by the σ–ρ Hammett plot. The second-order rate constant for the addition reaction of styrene was found to be of the same order of magnitude as that of butadiene. The presence of butadiene in the reaction system showed no effect on the reactivity of styrene.