Editing Metallocene (section)

===Using a metal salt and cyclopentadienyl reagents===
Sodium cyclopentadienide (NaCp) is the preferred reagent for these types of reactions. It is most easily obtained by the reaction of molten sodium and dicyclopentadiene.<ref>{{cite journal |last1= Panda |first1= T. K. |last2= Gamer |first2= M. T. |last3= Roesky |first3= P. W. |year= 2003 |title= An Improved Synthesis of Sodium and Potassium Cyclopentadienide |journal= Organometallics |volume= 22 |issue= 4|page= 877 |doi= 10.1021/om0207865}}</ref> Traditionally, the starting point is the cracking of [[dicyclopentadiene]], the dimer of cyclopentadiene. Cyclopentadiene is deprotonated by strong bases or alkali metals.

:MCl<sub>2</sub> + 2&nbsp;NaC<sub>5</sub>H<sub>5</sub> → (C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>M + 2&nbsp;NaCl {{space|10}} (M = V, Cr, Mn, Fe, Co; solvent = THF, DME, NH<sub>3</sub>)

:CrCl<sub>3</sub> + 3&nbsp;NaC<sub>5</sub>H<sub>5</sub> → [(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>Cr] + {{1/2}}&nbsp;"C<sub>10</sub>H<sub>10</sub>" + 3&nbsp;NaCl

NaCp acts as a reducing agent and a ligand in this reaction.