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

摘要

Hydride abstraction from the neutral gold cyclo-heptatrienyl complex [(P)Au(η~1-C7H7)] (P=P(tBu)2(o-biphenyl)) with triphenylcarbenium tetrafluoroborate at —80°C led to the isolation of the cationic gold cyclohepta-trienylidene complex [(P)Au(η~1-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 CI 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.