Synthesis, characterization and catalytic study of Schiff base copper(I) complexes for the amination of aryl halide

A series of Schiff base copper(I) complexes [Cu(L1)(PPh3)2]X (1a–d) and [Cu(L2)(PPh3)2]X (2a–d) [where L1 – (3-trifluoromethyl-phenyl)-pyridine-2-ylmethylene-amine and L2 – 2-chloro-(5-trifluoromethyl-phenyl)-pyridine-2-ylmethylene-amine); image] have been synthesized by the reaction of 3-aminobenzotrifluoride and 3-amino-4-chlorobenzotrifluoride with 2-pyridinecarboxaldehyde followed by the reaction with [Cu(MeCN)2(PPh3)2]Cl, [Cu(MeCN)2(PPh3)2]CN, [Cu(MeCN)2(PPh3)2]ClO4 and [Cu(MeCN)2(PPh3)2]BF4. The Schiff base ligands L1, L2 and complexes 1a–d and 2a–d were then characterized by elemental analysis, IR, UV–visible and 1H NMR spectral studies. The catalytic activity of these complexes was tested and it was found that all the complexes worked as active catalyst for the amination of iodobenzene at low temperature.