Redox transmetallation has been a very versatile synthetic approach to organolanthanoid complexes. We have developed a very high yielding and simple approach using lanthanoid metals as starting materials and treating them with organomercury reagents such as Hg(C6F5)2. These reactions generate Ln(C6F5)x (x = 2, 3 depending on the lanthanoid metal) and can be used to produce many other metal organic complexes of the lanthanoids by treatment with protic reagents such as acidic organics, amines and alcohols. Alternatively, the chemistry can be performed in a one-pot synthesis as a redox transmetallation/protolysis reaction where lanthanoid metal, Hg(C6F5)2 and LH (protic reagent) can be added to produce LnLx (x = 2, 3);
e.g. Ln + Hg(C6F5)2 + 2LH ----> LnL2 + Hg + 2C6F5H (for lanthanoid divalent metals)
While this chemistry works beautifully, as may be expected, it has attracted criticism for its involvement with the toxic mercury reagents, so more recently we have developed greener approaches in this synthetic endeavour. We have replaced the mercury reagents with organobismuth(III), Ag(I) and Cu(I) reagents in similar chemical pathways to synthesise the lanthanoid organometallics.1-3 The chemistry has required new approaches to organosilver reagents and has uncovered some unusual Bi chemistry. Most current findings in this story will be covered in this presentation, particularly more recent advances in using copper reagents for the redox transmetallation process.
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