Since the first report on the synthesis of a organolanthanide(III) hydride over 40 years ago, the field has witnessed enormous growth with hundreds of examples of organolanthanide(III) hydride based on every element in the lanthanide series. These complexes have now found applications in a range of industrially and academically important catalytic transformations, such as hydroboration, hydroamination and olefin polymerisation. In contrast, the synthesis and reactivity of lanthanide(II) hydrides is underdeveloped, with only a handful of examples in the literature.
The reactivity of these organolanthanide(II) hydrides is already beginning to diverge from that reported for the well-established organolanthanide(III) hydrides. For example, we have recently demonstrated that a low-coordinate organoytterbium(II) hydride could facilitate the first example of catalytic nucleophilic alkylation of benzene. This presentation will cover the new reactivity we have uncovered on our journey to extend the range of organolanthanide(II) hydrides beyond ytterbium to europium and samarium, and what we have found with thulium.