Synthesis, Structure, and Reactivity of a Gold Carbenoid Complex That Lacks Heteroatom Stabilization


  • We acknowledge the NSF (CHE-1213957) for support of this research. R.J.H. was supported in part through a Kathleen Zielek fellowship (Duke University). We thank Dr. Rachel E. M. Brooner for performing initial experiments directed toward the synthesis of complex 1.


Hydride abstraction from the neutral gold cycloheptatrienyl complex [(P)Au(η1-C7H7)] (P=P(tBu)2(o-biphenyl)) with triphenylcarbenium tetrafluoroborate at −80 °C led to the isolation of the cationic gold cycloheptatrienylidene complex [(P)Au(η1-C7H6)]+ BF4 in 52 % yield, which was characterized in solution and by single-crystal X-ray diffraction. This cycloheptatrienylidene complex represents the first example of a gold carbenoid complex that lacks conjugated heteroatom stabilization of the electron-deficient C1 carbon atom. The cycloheptatrienylidene ligand of this complex is reactive; it can be reduced by mild hydride donors, and converted to tropone in the presence of pyridine N-oxide.