| 研究実績の概要 |
The cleavage of carbon-carbon (C-C) bonds by transition metals is of fundamental interest and plays an important role in the production of fuels and valued chemicals from natural resources such as petroleum and biomass. However, C-C bonds are stable and difficult to break under ordinary conditions. Here we found that the reaction of a trinuclear titanium polyhydride complex with benzene, in which benzene molecule was transformed to a methylcyclopentenyl unit through the cleavage and rearrangement of the aromatic carbon skeleton at ambient temperature. The DFT calculation was carried out to clarify the reaction mechanism, which indicated that this transformation, including hydrometallation and C-C and C-H bond cleavage and formation, was accomplished through the cooperation of the multiple Ti-H sites in a trinuclear titanium framework. Besides, we found the titanium hydride complex could show special reactivities toward other aromatic hydrocarbons (including some heterocycles). Although attempts to make the stoichiometric reactions become catalytic processes using hydrogen and various hydride reagents was not successful.
This work demonstrated that multimetallic titanium hydrides can serve as a unique platform for the activation of aromatic molecules, offering new opportunities for the transformation and functionalization of inactive aromatics. Some of this year's results has been reported in the conference and manuscript is in preparation.
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