| Transition metal mediated addition of dihydrogen (H2) to organic compounds ("hydrogenation") is of paramount importance to the chemical industry, with applications ranging from the production of refined oil and fertilizers to pharmaceuticals and fine chemicals. In addition, dihydrogen could potentially be used as a clean and valuable alternative to fossil fuels. The application of dihydrogen in any process hinges on our ability to break the relatively strong H2 bond, and subsequently convert it into useful products. Traditionally, the activation of dihydrogen is performed using precious metal catalysts, but these are in general both costly and environmentally unfriendly. Recently, the group of Prof. Stephan has uncovered a fundamentally new way to activate H2 and transfer the two hydrogen atoms to an unsaturated organic substrate. This procedure makes use of a so-called ?Frustrated Lewis Pair? (FLP). These are based on the combination of a phosphine (PR3) and a borane (e.g., B(C6F5)3), in which the large phosphine substituents (R) prevent quenching of the reactivity by formation of a classical Lewis adduct. We propose to elucidate the mechanisms involved in these transformations. With this knowledge we will explore the scope of substrates that can be hydrogenated, and develop new classes of FLPs. |
