title: Vitamin B(12) model complex catalyzed methyl transfer reaction to alkylthiol under electrochemical conditions with sacrificial electrode.
abstract: Catalytic methyl transfer reactions from methyl tosylate to 1-octanethiol catalyzed by heptamethyl cobyrinate perchlorate, [Cob(II)7C(1)ester]ClO(4), were investigated under electrochemical conditions. As a model study for the cobalamin-dependent methyl transfer reaction from methyltetrahydrofolate to homocysteine, controlled-potential electrolyses were carried out at -1.0 V vs. Ag/AgCl using a zinc plate as the sacrificial anode at 50 degrees C in the dark. A turnover behaviour for the methyl transfer reaction was observed for the first time under non-enzymatic reaction conditions. Co(I) species, which is generated from the continuous electrolysis of [Cob(II)7C(1)ester]ClO(4), and its methylated CH(3)-Co complex were found to be important intermediates. The mechanism for such a methyl transfer reaction was investigated by product analysis, electronic spectroscopy and ESR spin-trapping experiments. A simple vitamin B(12) model complex was also utilized as the catalyst for the methyl transfer reaction.
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka, 819-0395, Japan.
authors.forename: Ling
authors.initials: L
authors.lastname: Pan
authors.forename: Hisashi
authors.initials: H
authors.lastname: Shimakoshi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Masuko
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hisaeda
mesh_terms: D001557:Benzenesulfonates / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry; D004566:Electrodes; D008745:Methylation; D010084:Oxidation-Reduction; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014805:Vitamin B 12 / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
chemical_list: D001557:Benzenesulfonates; D013438:Sulfhydryl Compounds; D003035:Cobalt; C402924:n-octanethiol; C506825:methyl tosylate; D015032:Zinc; D014805:Vitamin B 12