Olefin polymerization processes are described herein. In one embodiment, the process generally includes introducing propylene monomer to a reaction zone, disposing an isospecific metallocene catalyst within the reaction zone, wherein the isospecific metallocene catalyst has the formula: (SiRA2)(CpRB4)(FluRC8)MAn ; wherein Si is silicon and is a structural bridge between Cp and Flu, Cp is a cyclopentadienyl group, Flu is a fluorenyl group, M is a transition metal, A is a leaving group, n is an integer equal to the valence of M minus 2, RA is independently selected from hydrogen, alkyls, aromatics and combinations thereof, RB is independently selected from hydrogen, alkyls and combinations thereof and RC is independently selected from hydrogen, alkyls, aromatics and combinations thereof, contacting the propylene monomer with the isospecific metallocene catalyst to form isotactic polypropylene and recovering the isotactic polypropylene from the reaction zone.