Synthesis and characterization of new square planar heteroleptic cationic complexes [Ni() β-oxodithioester-dppe]; their use as a catalyst for Chan-Lam coupling

Novel heteroleptic [Ni( ii ) β-oxodithioester-dppe] + PF 6 − complexes (β-oxodithioester = methyl-3-hydroxy-3-benzyl-2-propenedithioate L1 1 , methyl-3-hydroxy-3-( p -methoxyphenyl)-2-propenedithioate L2 2 , methyl-3-hydroxy-3-(naphthyl)-2-propenedithioate L3 3 , methyl-3-hydroxy-3-( p -chlorophenyl)-2-propenedithioate L4 4 , methyl-3-hydroxy-3-( p -bromophenyl)-2-propenedithioate L5 5 and methyl-3-hydroxy-3-( p -cyanophenyl)-2-propenedithioate L6 6 ) have been synthesized and characterized by elemental (C, H, N) analysis, ESI-MS, IR, UV-visible, 1 H, 13 C{ 1 H}, 31 P{ 1 H} and 19 F{ 1 H} NMR spectroscopy. The distorted square planar structures of the isomorphous cationic complexes 2 , 3 , 4 and 5 have been determined by X-ray crystallography. The catalytic activities of 1-6 were investigated for the Chan-Lam coupling reaction involving arylboronic acids and amines to afford N -arylated products in good to excellent yields under mild conditions with 1 mol% catalyst loading. This catalytic protocol offers significant functional group tolerance, and is endowed with a broad substrate scope. Six new structurally characterized heteroleptic cationic [Ni( ii ) β-oxodithioester-dppe] + PF 6 − complexes as efficient catalysts for Chan-Lam coupling reaction affording N -arylated products with significant functional group tolerance.