Autoxidation of thiol-containing amino acid to its disulfide derivative that links two copper(ii) centers: the important role of auxiliary ligand

Conversion of a thiol-containing amino acid, d-penicillamine or l-cysteine, to its disulfide derivative, d-penicillamine disulfide or l-cystine, which bridges two copper(ii) centers in a bis(bidentate-N,O) mode, is reported.