Synthesis of Palladium complexes derived from Amido linked N‐Heterocyclic Carbenes and their use in Suzuki cross coupling reactions

Abstract

Treatment of 1-(n-butyl)-3-N-(2-Ar)acetamido-1, 3-imidazolium chloride (Ar = furylmethyl,phenylmethyl) with excess K 2 CO 3 and [PdCl 2 (LÀ L)] (LÀ L=2 PPh 3 , dppf) afforded orange compounds of composition [(1-(n-butyl)-3-N-(2-Ar)acetamido-1,3-imidazol-2ylidene)] 2 Pd (Ar = furylmethyl; phenylmethyl). These complexes were characterized by NMR ( 1 H and 13 C{ 1 H} NMR), IR and microanalysis data. Subsequently, the catalytic efficiency of these complexes for cross coupling reactions between 4-haloarenens (halo = Br, I) and phenylboronic acid was studied under different solvents (acetonitrile, THF and DMF), temperatures with different catalyst loadings. The molecular structure of [(1-(nbutyl)-3-N-(2-furylmethyl)acetamido-1, 3-imidazol-2-ylidene)] 2 Pd was established by single crystal X-ray diffraction analysis.