A Transition-Metal−η<sup>4</sup>-Diene Cation Can Undergo Nucleophilic Addition at the Internal Carbon Jang-Shyang Fan Rai-Shung Liu 10.1021/om971033z.s001 https://acs.figshare.com/articles/journal_contribution/A_Transition-Metal_sup_4_sup_-Diene_Cation_Can_Undergo_Nucleophilic_Addition_at_the_Internal_Carbon/3781578 Treatment of CpW(CO)<sub>2</sub>(η<sup>4</sup>-cyclohexadiene)BF<sub>4</sub> with RMgBr (R = methylvinyl, phenyl, naphthyl) in cold THF (−78 °C) afforded the CpW(CO)<sub>2</sub>[(1,2,4-η)-1-CO-2-R-cyclohexene] complex as the major product; this result provides an example of a nucleophile attacking the internal carbon of a cationic η<sup>4</sup>-diene fragment. 1998-02-24 00:00:00 naphthyl diene fragment Undergo Nucleophilic Addition cationic η 4 methylvinyl Internal Carbon Treatment CO phenyl THF nucleophile Diene Cation cyclohexadiene RMgBr CpW