Synthesis of Monosubstituted Cyclopentadienyl Ruthenium Complexes from the Reactions of 6-Substituted Fulvenes with RuHCl(PPh₃)₃

Reactions between 6-substitued fulvenes and the hydride complex RuHCl(PPh3)3 are described. Treatment of RuHCl(PPh3)3 with fulvenes without sp3-CH protons at the carbon α to the exocyclic carbon of fulvene produces cleanly monosubstituted cyclopentadienyl ruthenium complexes (η5-C5H4R)RuCl(PPh3)2 via hydride transfer to the electrophilic exocyclic carbon of fulvenes. When fulvenes containing sp3-CH protons at the carbon α to the exocyclic carbon were used, the reactions produce the expected (η5-C5H4R)RuCl(PPh3)2 complexes along with minor amounts of vinylcyclopentadienyl ruthenium complexes due to dehydrogenation.