Synthesis,Crystal Structure of Tetra-Nuclear Macrocyclic Cu(II) Complex Material and Its Application as Catalysts for A3 Coupling Reaction

A novel tetra-nuclear macrocyclic Cu(II) complex has been synthesized by the reaction of cupric acetate monohydrate with N-acetyl-l-phenylalanine and 4,4-bipyridine in water/ethanol (v:v = 1:1) solution, and characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. The results show that the Cu(II) complex belongs to monoclinic, space group P ₂₁ with a = 14.993(3) Å, b = 14.831(3) Å, c = 22.262(4) Å, β = 99.37(3)°, V = 4884.2(16) Å³, Z = 2, D _c  = 1.420 μg m^?3, μ = 0.942 mm^?1, F(000) = 2,160, and final R ₁ = 0.0701, ωR ₂ = 0.1905. The molecules form three dimensional tubular structures by the interaction of hydrogen bonds and π–π interaction. The A³ coupling reaction of phenylacetylene, aldehyde and amine (piperidine) in the presence of Cu(II) complex as an efficient heterogeneous catalyst has been studied. The catalyst displayed high activity and afforded the corresponding propargylamines with excellent yields. The Cu(II) complex catalyst was reused three times without significant loss of its catalytic activity.