Mechanistic study of the reaction of vitamin B12s with 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane

Abstract

The reaction of vitamin B_12s with 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane results in the formation of trans-4,4′-dichlorostilbene in a two-step process. In the first step, there is a nucleophilic attack by the cobalt(I) at C-1 resulting in the displacement of chloride ion and formation of an alkyl cobalamin with a chlorine atom on the α-carbon. The second step is a cobalt chloride α-elimination which proceeds through a carbenoid type intermediate that readily rearranges to the product.