Treatment of Cp*2Os2Br4 with 3-bromo-2-methylpropene or 1,3-cyclooctadiene affords the
2-methylpropenyl and cyclooctenyl products Cp*Os(η3-C4H7)Br2 and Cp*Os(η3-C8H13)Br2,
respectively. The monoalkyl complexes Cp*Os(η3-C4H7)MeBr and Cp*Os(η3-C4H7)(CH2SiMe3)Br can be generated by treating Cp*Os(η3-C4H7)Br2 with MgMe2 or LiCH2SiMe3. The dimethyl
complex Cp*Os(η3-C4H7)Me2 can be synthesized from Cp*Os(η3-C4H7)Br2 by addition of
methyllithium. In contrast, addition of ethyllithium to Cp*Os(η3-C4H7)Br2 yields the ethylene
complex Cp*Os(η3-C4H7)(η2-C2H4) and a small amount of Cp*Os(η3-C4H7)H2. The latter
dihydride can be synthesized in better yield by treating Cp*Os(η3-C4H7)Br2 with LiAlH4.
When the dimethyl complex Cp*Os(η3-C4H7)Me2 is protonated with HBF4 in the presence of
H2O, the aqua complex [Cp*Os(η3-C4H7)Me(H2O)][BF4] is formed.