Thiol peroxidase-like activity of some intramolecularly coordinated diorganyl diselenides

Abstract

Several new diaryl diselenides having intramolecular coordinating groups have been synthesized by ortho-lithiation/Na₂Se₂ routes in good yield. Bis[2-(N-phenylferrocenecarboxamide)] diselenide (10), bis[2-(N-tert-butylferrocenecarboxamide)] diselenide (11), (S)(S)-bis[2(-N-phenethylferrocene-carboxamide)] diselenide (12) were synthesized by the ortho-lithiation route. Bis[2-(N,N-dimethyl-aminomethylnaphthyl)] diselenide (13) was synthesized by lithium/bromide exchange reaction whereas bis(2,4-dinitrophenyl) diselenide (14) was prepared by the reaction of disodium diselenide with 2,4-dinitro-1-chlorobenzene. Thiol peroxidase-like activities of the diorganodiselenides have been evaluated by using H₂O₂ as substrate and PhSH as cosubstrate. Diselenides (13) and (14) with dimethylami-nomethyl- or nitro-donor groups in close proximity to selenium, show much better thiol peroxidase-like activities compared to diselenides 10-12 with amide donor groups. Cyclic voltammetry study of diselenides 10-12 derived from redox-active ferrocenamide has been carried out.