Consecutive Butylations on the Cyclopentadienyl Ring of the [(η5-C5H5)Fe(CO)2PPh3]+ Cation
摘要:
The replacement of acidic hydrogen atoms in cyclopentadiene by alkyl groups would normally involve a repetitive deprotonation and then electrophilic alkylation. By means of eta(4)-Fe complexation, one can reverse the polarity of cyclopentadiene and utilize multiple hydride abstraction/nucleophilic alkylation cycles in the preparation of the polybutylcyclopentadienes in the neutral eta(4)-Fe form and the corresponding cyclopentadienyl complexes in the cationic eta(5)-Fe form.