Synthesis and Reactivity of Tricarbonyl(η\u3csup\u3e5\u3c/sup\u3e-4-triethylsilyl-1methylpentadienyl) Iron(+1) Cation

Tricarbonyl(η5-4-triethylsilyl-1-methylpentadienyl)iron(+1) hexafluorophosphate was prepared by the protonation of γ-endo tricarbonyl (η4-5-triethylsilyl-3,5-hexadien-2-ol)iron with hexafluorophosphoric acid. The cation reacts with H2O, CH3OH, NaBH3CN, PPh3, sodium dimethylmalonate and dimethyl cuprate in a regiospecific fashion by nucleophilic attack at C1. The regioselectivity for nucleophilic attack appears to be predominantly the result of steric control