2,6-Lutidine-linked bis-saturated NHC pincer ligands, silver complexes and transmetallation

Abstract

Pincer ligands have proven to be valuable tools in the formation of robust transition metal complexes. To date, pincer ligands have featured an extremely diverse array of structural motifs, backbones and donor units. Carbene ligands have been easily integrated into a variety of pincer ligand structures and yet there are very few examples in which saturated NHC donor moieties are featured. Saturated NHCs are known to have unique donor and acceptor properties compared to their unsaturated analogs and therefore their implementation into pincer structures should lead to new electronic properties of the coordinated metal. To expand the use of saturated NHCs in pincer ligand chemistry, a bis-NHC pincer ligand, featuring a 2,6-lutidine linker, has been synthesized. The proligand can be directly metalated using silver oxide and the silver salt has been used in transmetallation chemistry to generate Ni(II) pincer complexes. This ligand is an excellent addition to known pincer ligands and will have applications in catalysis and other areas.