Copper(I) Complexes of Phenanthro-Annulated N-Heterocyclic Carbenes: Synthesis and Transmetalation Reactions

摘要

Copper(I) complexes with phenanthro-annulated N-heterocyclic carbene ligands were prepared by reaction of imidazolium salts with copper(I) oxide. Transmetalation of the copper complexes with [RhCl(cod)]_2 in usual solvents like CH_2Cl_2 led to an equilibrium between the reactants and the products. For rhodium complexes 4 and 5 this equilibrium could be shifted to the product side by carrying out the reaction in acetonitrile. The ester functionalized rhodium complex 6 was prepared in a two phase mixture of chloroform and aqueous CaCl_2 starting from copper complex 3c. The rhodium complexes were characterized by NMR and X-ray measurements.