Kinetics and mechanism for the elimination of hydrogen between dimethylaluminum hydride and benzylamine

Article abstract of DOI:10.1021/ic50223a018

The rate of elimination of hydrogen from dimethylaluminum hydride and benzylamine has been measured at -63°C in toluene solution. All experimental data are consistent with a second-order rate law which is complicated by a series of equilibria. Initial rate data were correlated with a rate law and fitted to an appropriate mechanism. The following steps of the mechanism determine the rate of elimination of hydrogen during the early stages of the reaction: H(CH₃)₂AlN(CH₂C₆H₅)H ₂ + N(CH₂C₆H₅)H₂ ?^K1 H(CH₃)₂Al[N(CH₂C₆H ₅)H₂]₂ H(CH₃)₂AlN(CH₂C₆H₅)H ₂ ?^κ2 H(CH₃)₂Al + N(CH₂C₆H₅)H₂ H(CH₃)₂Al + N(CH₂C₆H₅)H₂ →^κ H₂ + (CH₃)₂AlN(CH₂C₆H₅)H Additional equilibria which involve the aluminum-nitrogen product from the elimination reaction are proposed in order to fully describe the chemistry of the system. The large number of equilibria which complicate the kinetics of the reaction are related to the high basicity of benzylamine.