Methyl-transfer reaction to alkylthiol catalyzed by a simple vitamin B12 model complex using zinc powder

Abstract: The catalytic methyl-transfer reaction from methyl tosylate to 1-octanethiol was carried out in the presence of a simple vitamin B12 model complex, [Co(III){(C2C3)(DO)(DOH)pn}Br2], with zinc powder as the reducing reagent at 50°C. Such a catalytic reaction proceeded via the formation and dissociation of a cobalt–carbon bond in the simple vitamin B12 model complex under non-enzymatic conditions. The mechanism for the methyl-transfer reaction was investigated by electronic and mass spectroscopies. The Co(I) species, which is generated from the reduction of the catalyst by the zinc powder, and its methylated CH3–Co complex were found to be indispensable intermediates. [Copyright &y& Elsevier]