Reduction of mono- and dichlorobiphenyls with sodium-naphthalene complex

Reactivity of low-chlorinated congeners of polychlorinated biphenyls in relation to sodiumnaphthalene complex in THF was studied. It was shown that the rate of reduction of these substrates weakly depended on their structure. The regioselectivity of the first stage of reduction of dichlorobiphenyls may be caused by relative stability of the intermediately formed aryl radicals. Kinetic analysis of the processes taking place in the system showed that sodium-naphthalene complex alongside with one-electron reduction of dichlorobiphenyls is involved also in the multi-electron reduction leading directly to biphenyl avoiding the stage of formation of monochlorobiphenyl.