ja048573p_si_002.cif (69.33 kB)

Properties and Reactivity of Chlorovinylcobalamin and Vinylcobalamin and Their Implications for Vitamin B12-Catalyzed Reductive Dechlorination of Chlorinated Alkenes

Download (69.33 kB)
posted on 02.02.2005, 00:00 by Kevin M. McCauley, Derek A. Pratt, Scott R. Wilson, Justin Shey, Theodore J. Burkey, Wilfred A. van der Donk
Vitamin B12-catalyzed reductive dechlorination of perchloroethylene (PCE) and trichloroethylene (TCE) is a potential strategy for cleanup of polluted environments. Presented are crystal structures of vinylcobalamin 2 and cis-chlorovinylcobalamin 1. They show a strong resistance toward photolysis. Reduction of 2 is difficult, but reduction of 1 occurs readily and produces 2. The mechanism of this latter reaction involves acetylene as an intermediate. These and other findings are discussed in the context of environmental studies on B12-catalyzed dechlorination of PCE and TCE and investigations of the haloalkene reductive dehalogenases that catalyze similar reactions.