Treatment of [Mn(CO)3(η5-C7H9)] (1) with phenyllithium in diethyl ether gave the acyl complex [Li- (Et2O)2][Mn(CO)2(C(O)Ph)(η5-C7H9)] (2), which in turn reacted with (CH3)3SiCl to form the bicyclo[3.2.1]oct-2-ene complex 3 via intramolecular carbene-cycloheptadienyl coupling. Protonation of 3 gave the bidentate η2-olefin-η6-arene cation 4, which can be desilylated with excess acid to form the hydroxy derivative 5. The regiochemistry of the carbene-cycloheptadienyl coupling reaction has been probed using the methyl-substituted species [Mn(CO)3(η5- C7H8Me)] (1b). The protonation reaction was shown to occur exclusively at the olefin of the σ-allyl moiety in 3 using the methyl-substituted derivative 3b. Complexes 4 and 5 added nucleophiles (H−, [CH(CO2Me)2]−, and MeMgCl) to the arene ligand, rather than at the predicted olefin site, to form the cyclohexadienyl species 6 and 7, respectively. Treatment of 3 with PPh3 in CH2Cl2 gave a novel species, [(η3-C8H9)(OTMS)(η2-Ph)]Mn(CO)2(PPh3) (8), in which a distorted manganese-η2-arene group is present. The rhenium analog of 2 was prepared and gave the stable carbene complex 9 upon treatment with (CH3)3SiCl.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry