The cleavage of carbon−carbon (C−C) bonds by transition metals is of great interest, especially as this transformation can be used to produce fuels and other industrially important chemicals from natural resources such as petroleum and biomass. Carbon−carbon bonds are quite stable and are consequently unreactive under many reaction conditions. In the industrial naphtha hydrocracking process, the aromatic carbon skeleton of benzene can be transformed to methylcyclopentane and acyclic saturated hydrocarbons through C−C bond cleavage and rearrangement on the surfaces of solid catalysts1,2,3,4,5,6. However, these chemical transformations usually require high temperatures and are fairly non-selective. Microorganisms can degrade aromatic compounds under ambient conditions, but the mechanistic details are not known and are difficult to mimic7. Several transition metal complexes have been reported to cleave C−C bonds in a selective fashion in special circumstances, such as relief of ring strain, formation of an aromatic system, chelation-assisted cyclometallation and β-carbon elimination8,9,10,11,12,13,14,15. However, the cleavage of benzene by a transition metal complex has not been reported16,17,18,19. Here we report the C−C bond cleavage and rearrangement of benzene by a trinuclear titanium polyhydride complex. The benzene ring is transformed sequentially to a methylcyclopentenyl and a 2-methylpentenyl species through the cleavage of the aromatic carbon skeleton at the multi-titanium sites. Our results suggest that multinuclear titanium hydrides could serve as a unique platform for the activation of aromatic molecules, and may facilitate the design of new catalysts for the transformation of inactive aromatics.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
X-ray crystallographic coordinates of 2, 4, 5 and 6 have been deposited at the Cambridge Crystallographic Database under accession numbers 981670–981673.
Jones, D. S. J. & Pujadó, P. R. Handbook of Petroleum Processing (Springer, 2006)
Weitkamp, J. Handbook of Heterogeneous Catalysis Vol. 1, 2nd edn (eds Ertl, G., Knözinger, H., Schüth, F. & Weitkamp, J. ) Ch. 14.2 (Wiley-VCH, 2008)
Watanabe, R., Suzuki, T. & Okuhara, T. Skeletal isomerization of alkanes and hydroisomerization of benzene over solid strong acids and their bifunctional catalysts. Catal. Today 66, 123–130 (2001)
McVicker, G. B. et al. Selective ring opening of naphthenic molecules. J. Catal. 210, 137–148 (2002)
Benitez, V. M., Grau, J. M., Yori, J. C., Pieck, C. L. & Vera, C. R. Hydroisomerization of benzene-containing paraffinic feedstocks over Pt/WO3-ZrO2 catalysts. Energy Fuels 20, 1791–1798 (2006)
Kazakov, M. O. et al. Hydroisomerization of benzene-containing gasoline fractions on a Pt/SO42−-ZrO2-Al2O3 catalyst: I. Effect of chemical composition on the phase state and texture characteristics of SO42−-ZrO2-Al2O3 supports. Kinet. Catal. 51, 438–443 (2010)
Bugg, T. D. H. & Winfield, C. J. Enzymatic cleavage of aromatic rings: mechanistic aspects of the catechol dioxygenases and later enzymes of bacterial oxidative cleavage pathways. Nat. Prod. Rep. 15, 513–530 (1998)
Bishop, K. C. Transition metal catalysed rearrangements of small ring organic molecules. Chem. Rev. 76, 461–486 (1976)
Crabtree, R. H. The organometallic chemistry of alkanes. Chem. Rev. 85, 245–269 (1985)
Jones, W. D. The fall of the C–C bond. Nature 364, 676–677 (1993)
Rybtchinski, B. & Milstein, D. Metal insertion into C–C bonds in solution. Angew. Chem. Int. Ed. 38, 870–883 (1999)
Jun, C. Transition metal-catalysed carbon–carbon bond activation. Chem. Soc. Rev. 33, 610–618 (2004)
Murakami, M. & Matsuda, T. Metal-catalysed cleavage of carbon-carbon bonds. Chem. Commun. 47, 1100–1105 (2011)
Ruhland, K. Transition-metal-mediated cleavage and activation of C–C single bonds. Eur. J. Org. Chem. 2012, 2683–2706 (2012)
Takao, T. & Suzuki, H. Skeletal rearrangement of hydrocarbyl ligands on a triruthenium core induced by chemical oxidation. Coord. Chem. Rev. 256, 695–708 (2012)
Sattler, A. & Parkin, G. Cleaving carbon–carbon bonds by inserting tungsten into unstrained aromatic rings. Nature 463, 523–526 (2010)
Kira, M., Ishida, S., Iwamoto, T. & Kabuto, C. Excited-state reactions of an isolable silylene with aromatic compounds. J. Am. Chem. Soc. 124, 3830–3831 (2002)
Ellis, D., McKay, D., Macgregor, S. A., Rosair, G. M. & Welch, A. J. Room-temperature C–C bond cleavage of an arene by a metallacarborane. Angew. Chem. Int. Ed. 49, 4943–4945 (2010)
Szyszko, B., Latos-Grażyński, L. & Szterenberg, L. A facile palladium-mediated contraction of benzene to cyclopentadiene: transformations of palladium(II) p-benziporphyrin. Angew. Chem. Int. Ed. 50, 6587–6591 (2011)
Van Hove, M. A., Lin, R. F. & Somorjai, G. A. Surface structure of coadsorbed benzene and carbon monoxide on the rhodium(III) single crystal analysed with low energy electron diffraction intensities. J. Am. Chem. Soc. 108, 2532–2537 (1986)
Dyson, P. J. Arene hydrogenation by homogeneous catalysts: fact or fiction? Dalton Trans. 2964–2974 (2003)
Tardif, O., Hashizume, D. & Hou, Z. Hydrogenation of carbon dioxide and aryl isocyanates by a tetranuclear tetrahydrido yttrium complex. isolation, structures, and CO2 insertion reactions of methylene diolate and μ3-oxo yttrium complexes. J. Am. Chem. Soc. 126, 8080–8081 (2004)
Shima, T. & Hou, Z. Hydrogenation of carbon monoxide by tetranuclear rare earth metal polyhydrido complexes. selective formation of ethylene and isolation of well-defined polyoxo rare earth metal clusters. J. Am. Chem. Soc. 128, 8124–8125 (2006)
Nishiura, M. & Hou, Z. Novel polymerization catalysts and hydride clusters from rare-earth metal dialkyls. Nature Chem. 2, 257–268 (2010)
Shima, T. et al. Molecular heterometallic hydride clusters composed of rare-earth and d-transition metals. Nature Chem. 3, 814–820 (2011)
Shima, T. et al. Dinitrogen cleavage and hydrogenation by a trinuclear titanium polyhydride complex. Science 340, 1549–1552 (2013)
Brookhart, M. & Green, M. L. H. Carbon-hydrogen-transition metal bonds. J. Organomet. Chem. 250, 395–408 (1983)
Suzuki, H., Takaya, Y., Takemori, T. & Tanaka, M. Selective carbon-carbon bond cleavage of cyclopentadiene on a trinuclear ruthenium pentahydride complex. J. Am. Chem. Soc. 116, 10779–10780 (1994)
Brown, D. B. et al. Cluster-mediated ring contraction: synthesis and characterisation of [Ru6(μ3-H)(μ4-η2-CO)2(CO)13(η5-C5H4Me)] and [Ru6(μ3-H)(μ4-η2-CO)2(CO)13(η5-C5H3C3H6)]. J. Chem. Soc. Dalton Trans. 1909–1914 (1997)
Takao, T. et al. Synthesis and property of diruthenium complexes containing bridging cyclic diene ligands and the reaction of diruthenium tetrahydrido complex with benzene forming a μ-η2:η2-cyclohexadiene complex via partial hydrogenation on a Ru2 centre. Organometallics 30, 5057–5067 (2011)
This work was supported by a Grant-in-Aid for Young Scientists (B) (no. 26810041), a Grant-in-Aid for Scientific Research (C) (no. 26410082) and a Grant-in-Aid for Scientific Research (S) (no. 26220802) from JSPS, and an Incentive Research Grant from RIKEN. We thank J. Cheng for help with X-ray structure analyses, and A. Karube for conducting elemental analyses.
The authors declare no competing financial interests.
About this article
Cite this article
Hu, S., Shima, T. & Hou, Z. Carbon–carbon bond cleavage and rearrangement of benzene by a trinuclear titanium hydride. Nature 512, 413–415 (2014). https://doi.org/10.1038/nature13624
Dalton Transactions (2020)
Synthesis and Diverse Transformations of a Dinitrogen Dititanium Hydride Complex Bearing Rigid Acridane‐Based PNP‐Pincer Ligands
Angewandte Chemie International Edition (2020)
Activation and Transformation of Small Molecules by Multimetallic Early Transition Metal Hydride Clusters
Journal of Synthetic Organic Chemistry, Japan (2020)
Multimetallic Rare Earth and Group 4 Transition Metal Hydrides for Novel Transformations of Small Molecules
Journal of the Physical Society of Japan (2020)
Density functional theory investigation on the mechanism of dehydrogenation of cyclohexane catalyzed by heteronuclear NiTi+
Computational and Theoretical Chemistry (2020)