Structural Characterization, DFT Analysis and Catalysis by Highly Active Cationic Fe(II)‐Cu(I) Complexes in the Green Synthesis of Triazoles in Water

Abstract

AbstractTwo bimetallic Fe(II)‐Cu(I) complexes, with tetrahedral Cu(I) center stabilized in a S2P2 environment, were synthesized and fully characterized using single crystal X‐ray diffraction, multinuclear NMR, IR and UV‐Visible spectroscopy techniques. Density functional theory with PBE0‐D3(BJ) functional was employed to elucidate the electronic features of these novel metal complexes. The computational analysis revealed that while all Cu(I) complexes adopted a tetrahedral geometry in the gas phase with shorter P−Cu(I) bonds than the S−Cu(I) bonds. These cationic complexes were highly active in the catalytic cycloaddition reaction of azides onto terminal alkynes. The CuAAC reaction were carried out at room temperature with as low as 1 mg (0.1 mol %) of catalyst loading to deliver high yields of the corresponding 1,4 adducts of 1,2,3‐triazoles in water under aerobic conditions.