C-S bond cleavage in pyridylmethylthioether systems promoted by oxorhenium(V) ion

C-S bond cleavage in pyridylmethylthioether systems promoted by oxorhenium(V) ion has been established performing the reaction of 1,2-bis(2-pyridylmethylthio)ethane(BPT1), 1,3-bis(2-pyridyl-methylthio)propane(BPT2) and 3,4-bis(2-pyridylmethylthio)-5-methyltoluene (BPT3) with Bu4N[ReOCl4] in dry alcoholoic medium. In case of BPT1 and BPT2, new 2-(2-pyridylmethylthio)ethane-1-thiol ((LH)-H-1) and 3-(2-pyridylmethylthio)propane-1-thiol (OH) ligand, respectively were formed in situ through cleavage of one C-S(thioether) bond, resulting in the neutral oxorhenium(V) complexes of formulation [ReO(L-1)Cl-2] (1a) and [ReO(L-2)Cl-2] (1b); where as in case of BPT3, binary oxorhenium(V) complex of 3,4-dimercapto-toluene ligand ((LH2)-H-3), formulated as Bu4N[ReO(L-3)(2)] (1c) through cleavage of two C-S(thioether) bonds. The presence of picolinic acid, as by-product in the filtrates of the C-S bond cleavage reactions in dry alcohol, was detected by treatment of copper(II) salts and GC-MS techniques. But in hydrated alcoholic medium no C-S bond cleavage induced by ReO(V) ion occurred in any of the BPT systems rather the conversion of ReO(V) into perrhenate salt was observed; this reaction mixture, in turn on reaction with copper(II) nitrate trihydrate salt, produce [Cu(BPT)Cl]ReO4 (2) type complexes. The solid-state structures of complexes 1a and 2a were established by X-ray crystallography. (c) 2009 Elsevier B.V. All rights reserved.