Copper(II) Complexes with 3‐(2‐Pyridyl)‐5 <i>R</i> ‐1,2,4‐Triazoles: The Influence of Noncoordinating Substituent in Ligand on Structure and Potential for Oxidative Cleavage of Alkene Bonds and Henry Coupling

Twelve new mono‐ and polynuclear Cu(II) complexes derived from 3‐(2‐pyridyl)‐5 R ‐1,2,4‐triazoles (HL n , where R = Me, n = 1; R = Et, n = 2; R = i ‐Pr, n = 3; R = t ‐Bu, n = 4; R = Ph, n = 5; R = Bz, n = 6) containing other ligands, such as nitrate, aqua, or dimethylformamide (dmf), were obtained and structurally characterized. Nine compounds were tested as selective catalysts for the microwave‐assisted oxidation of neat styrene to benzaldehyde (up to 85% yield) via copper‐peroxide reactive species and its further ultrasound‐assisted conversion (up to 99% yield) to the syn ‐ and anti ‐ β ‐nitroethanol mixture with a remarkable diastereoselectivity to the anti‐ isomer.