Symmetrical non-chelating poly-N-heterocyclic carbenes

Abstract

A facile synthetic protocol, which utilized dehydrative condensation of phthalic anhydride and primary amines, for symmetrical non-chelating poly-N-heterocyclic carbene ligands was established. With the designed bi-functional building block, poly-NHC ligands having various denticities and geometries could be readily achieved by varying the structure of poly-amino compounds. Examination of catalytic activity of a series of poly-NHC–Ni complexes revealed the lack of electronic interference among NHC–metal units.