Voltammetric study of chiral active compound 4,4′-diisopropyl-2,2′-thiazoline and its interaction with copper(II)

The electrochemical investigation of the chiral active compound, (4S)‐4‐diisopropyl‐2‐2′‐bithiazoline (DPT), commonly used in asymmetric syntheses as well as in diastereoselective reactions, and its interaction with copper(II) ion by cathodic stripping voltammetry at a HMDE electrode, was performed. DPT reduction occurs in two steps, at potentials about −0.2 and −0.45V (vs. Ag/AgCl), through the formation of an electrodeposited layer of DPT‐Hg at the electrode surface. DPT complex with copper(II) is reduced at about −0.36 V, through the formation of DPT‐Cu deposit at the electrode surface. The reduction process of DPT‐Hg and DPT‐Cu complex, as well as DPT, depend upon pH, on the electrolyte solution, as well as on the concentration and ratio of the ligand and metal ion. The mechanisms of those electrode processes were investigated. Due to their strong adsorption, low concentration levels of DPT, through DPT‐Hg complex reduction, and copper, through DPT‐Cu complex reduction, about 10−9 M, can be determined, with the accumulation time of 10 minutes at 0.0 V (vs. Ag/AgCl), at pH 2.8 in 0.55 M NaCl.