Vitamin B12-dependent enzymes, involving the cobalt species as a catalytic center, mediate various molecular transformations in vivo. In order to use vitamin B12 derivatives (cobalamins) as green catalysts, various studies have been carried out such as a chemical modification of cobalamin or the fixation of B12 derivative on electrodes. The Co(I) species of vitamin B12 derivative is widely known as a supernucleophile that forms an alkylated complex by reaction with an alkyl halide. Such reaction is efficient for dehalogenation of various organic halides. Therefore, vitamin B12 derivatives can be used as catalysts for reductive degradation of organic pollutant such as DDT. In addition, the alkylated complex is a useful reagent for forming radical species as the cobalt-carbon bond is readily cleaved homolytically by photolysis or electrolysis. Therefore, the application of the alkylated complex to organic synthesis is quite interesting from the viewpoint of a radical-forming reagent. This review article summarizes recent progress in homogeneous and heterogeneous catalytic reactions mediated by vitamin B12 derivatives.
|Number of pages
|Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry
|Published - Aug 2005
All Science Journal Classification (ASJC) codes
- Organic Chemistry