Copper Complexes with N,N,N-Tridentate Quinolinyl Anilido-Imine Ligands: Synthesis and Their Catalytic Application in Chan-Lam Reactions.

The treatment of 2-(ArNC(H))C 6 H 4 -HNC 9 H 6 N with n -BuLi and the subsequent addition of CuCl 2 afforded the anilido-aldimine Cu(II) complexes 1 - 5 Cu[{2-[ArN=C(H)]C 6 H 4 }N(8-C 9 H 6 N)]Cl (Ar = 2,6- i Pr 2 C 6 H 3 ( 1 ), 2,4,6-(CH 3 ) 3 C 6 H 2 ( 2 ), 4-OCH 3 C 6 H 4 ( 3 ), 4-BrC 6 H 4 ( 4 ), 4-ClC 6 H 4 ( 5 )), respectively. All the copper complexes were fully characterized by IR, EPR and HR-MS spectra. The X-ray diffraction analysis reveals that 2 and 4 are mononuclear complexes, and the Cu atom is sitting in a slightly square-planar geometry. These Cu(II) complexes have exhibited excellent catalytic activity in the Chan-Lam coupling reactions of benzimidazole derivatives with arylboronic acids, achieving the highest yields of up to 96%.