Methods for the hydroalkenylation of conjugated, 1,3-dienes using a diimine catalyst. The method comprises mixing a diene having at least five carbon atoms and an iron diimine complex at a temperature of about −60° C. to about 23° C. to provide a catalyst solution; and introducing one or more alpha olefins at a pressure of at least 300 psig to obtain a product comprising the substituted diene monomer.