Synthesis of new Pd(II) complex with 1,5,5-trimethyl-2-(phenylselanyl)-6-oxa-bicyclo[2.2.2]octane as a ligand

Abstract

Organoselenium compounds have gained much attention during the last decade of years, partly due to their coordination abilities and interesting biological properties . Transition metal complexes bearing organoselenium ligands were proven to possess catalytic, biological and biomedical properties. They exhibit antioxidant, antimalarian, antitumor, antileucemic, antidiabetic and cytotoxic activity a , thus presenting promising pharmaceutical agents. In our previous work we have screened 2-(phenylselanylmethyl)oxolane (Y) for its antioxidant and antiproliferative efect on colon cancer cell line HCT-​116 and breast cancer cell line MDA-​MB-​231 b . Coordinating Y to Pd(II) gave complex which displayed cytostatic and cytotoxic abilities. Direct continuation of this line of work involves synthesization of Pd(II) complex with 2-(phenylselanyl)cineol (L) as more stericly hindered ligand, in order to compare its biological activities with those of Pd(II)-Y complex. Herein we report the synthesis of a new Pd(II) complex bearing organo-selenium moiety. Ligand L was obtained in high yields following a previously described procedure b . In order to obtain complex C, the compound L was then treated with an excess of PdCl 2 at 40 °C, in EtOH/MeOH mixture as a solvent system.(Scheme 1).