The cobalt-catalyzed 1,4-hydrovinylation of acyclic 1,3-dienes with various functionalized terminal alkenes is described. The mild reaction conditions are significant because they considerably reduce the amount of side products and for non acceptor-substituted alkenes the branched products are formed exclusively. The CoBr2(dppe) catalyst system controls the regiochemistry of the hydrovinylation process. Unsymmetrical 1,3-dienes yield products, where the new carbon-carbon bond is formed at the less substituted end of the 1,3-diene.
cobalt - 1,4-hydrovinylation reaction - alkene - 1,3-diene - 1,4-diene