POP-type ligands: Variable coordination and hemilabile behaviour

Hemilabile ligands ligands containing two or more potential donors to a metal centre, of which one or more can dissociate have the ability to provide a transition metal complex with open coordination sites at which reactivity can occur, or stabilise low coordinate intermediates along reaction pathways. POP type ligands and in particular POP, Xantphos, DBFphos and DPEphos-based ligands contain three possible binding sites: two phosphines and an ether linker, thus have the potential to show kappa(1)-, kappa(2)- or kappa(3)-binding modes. This review summarises the examples where POP-type ligands display hemilabile, or closely related variable coordination, characteristics in either synthesis or catalysis. (C) 2017 The Authors. Published by Elsevier B.V.