Reaction of unsaturated ligands with carbon number larger than four

5 Reaction of unsaturated ligands with carbon number larger than four 

Various nucleophiles such as carbanions, aromatics, amines and phosphines attack metal-bound unsaturated ligands with the carbon number 4, 5 and 6 (cf. 

The Davies-Green-Mingos rule predicts that the attack at butadiene ligand should occur at the terminal carbon, as is consistent with the OAc attack at the 

Pd-bound diene shown above. However, the kinetic product in the nucleophilic ahack at (diene)Fe(CO)3 was often due to the attack at internal carbon. Thus, for example, ( 7 -CH2CHCHCH2)Fe(CO)3 reacted with a carbanion at —78°C to give 

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