Trinuclear Cu(I)–NHC as NHC transfer agent: Synthesis of mono- and di-nuclear palladium and mercury complexes

Abstract

Mono and dinuclear palladium–NHC complexes of 1,3-bis(2-pyridyl)imidazolin-2-ylidene (py2im) ligand, such as [Pd(py2im)2](PF6)2 (2) [Pd2Cl2(py2im)2](PF6)2 (3), and [PdCl2(py2im)] (4) were synthesized by carbene transfer method using trinuclear Cu(I)–NHC complex, [Cu3(py2im)3](PF6)3 (1). Also addition of PPh3 to the solution of 3 or in the reaction medium of 1 with PdCl2 resulted in a mononuclear bisphosphine complex [PdCl(PPh3)2(py2im)](PF6) (5) which can also be prepared using trans-[PdCl2(PPh3)2] (6) and [Cu(PPh3)2(py2im)](PF6) (7) as precursors. In addition a mono nuclear complex [Hg(py2im)2](PF6)2 (8) was synthesized through carbene transfer from 1.