N-Heterocyclic Carbenes in the Synthesis of Axially Chiral Square-Planar Platinum Complexes

A new synthetic approach allows access to axially chiral square-planar platinum(II) complexes by combining an enantiomerically pure diphosphine (DuPHOS, BPE, or Chiraphos) and an unsymmetric NHC ligand. The same approach proved to be highly stereoselective when applied to the synthesis of a chiral triazolylidene−dppe mixed complex.