Cu(i) based catalysts derived from bidentate ligands and studies on the effect of substituents for N-arylation of benzimidazoles and indoles†
A family of Cu(I) complexes [Cu(L1–4)(Cl)(PPh3)] (C1–C4) were synthesized from bidentate ligands L1–L4 (where L1 = (E)-2-(2-benzylidene-1-phenylhydrazinyl)pyridine, L2 = (E)-N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)aniline, L3 = (E)-2-(2-(4-chlorobenzylidene)-1-phenylhydrazinyl)pyridine and L4 = (E)-2-(2-(4-nitrobenzylidene)-1-phenylhydrazinyl)pyridine) and characterized. The structure of complex C1 was authenticated by single-crystal X-ray diffraction. These complexes were utilised as catalysts for N-arylation of benzimidazoles and indoles. The effect of the substituents in the ligand frame of metal complexes were examined and the probable reaction pathway was scrutinized.