A new catalytic system using the combination RuCl2(DMSO)(4)/CH3CH2COON
a/DMSO/carboxylic acid which enables selective dimerization of acrylon
itrile to linear dimers without formation of propionitrile as a byprod
uct has been developed on the basis of a new working hypothesis of the
desirable reaction mechanism involving protonolysis of a C-Ru bond in
the intermediate.