New four-coordinated tetrahedral copper(I) complexes have been synthesized from the reactions between [CuCl₂(PPh₃)₂] and N-(diphenylcarbamothioyl)benzamide (HL1) or N-(diethylcarbamothioyl)benzamide (HL2) in benzene. These complexes have been characterized by elemental analyses, IR, UV/Vis, ¹H, ¹³C and ³¹P NMR spectroscopy. The molecular structure of both the complexes, [CuCl(HL1)₂(PPh₃)] (1) and [CuCl(HL2)(PPh₃)₂] (2) were determined by single-crystal X-ray diffraction, which reveals distorted tetrahedral geometry around each Cu(I) ion. The combination of 2 (0.005 mmol) with hydrogen peroxide (2.5 mmol) in acetonitrile is found to be an active catalyst for the oxidation of primary and secondary alcohols (0.5 mmol) to their corresponding acids and ketones, respectively, at room temperature.