Contrasting Reactivity of B-Cl and B-H Bonds at [ni(imes)2] to Form Unsupported Ni-boryls.

[Ni(IMes)2] reacts with chloroboranes via oxidative addition to form rare unsupported Ni-boryls. In contrast, the oxidative addition of hydridoboranes is not observed and products from competing reaction pathways are identified. Computational studies relate these differences to the mechanism of oxidative addition: B-Cl activation proceeds via nucleophilic displacement of Cl-, while B-H activation would entail high energy concerted bond cleavage.