| 研究実績の概要 |
During Fiscal Year 2018, the JSPS fellow Dr Orestes Rivada-Wheelaghan was involved in finalizing the research projects on the formation of heteropolymetallic complexes. Several directions were pursued:
1) Selective formation of Cu-Pd-Pd-Cu complexes was achieved using polynuclearing ligands proposed in this project. These complexes were found to react with terminal alkyne to give a binuclear Pd-Cu acetylide complex, which then undergoes C-C elimination from Pd(acetyline)(Aryl) center. This reactivity closely resembles the mechanism of the Sonogashira coupling. Our ligand platform allows to obtain model compounds that shed light on the mechanism of Sonogashira coupling as they feature Cu and Pd center in close proximity and allow to structurally characterize the intermediates. In collaboration with Agusti Lledos, we are currently finalizing DFT study of the detailed mechanism of C(sp)-C(sp2) coupling in multimetallic Cu-Pd complexes.
2) Using ligand modification, we also obtained a complex with "reversed" Pd-Cu-Cu-Pd core. Interestingly, this complex was found to be an active catalyst for gem-selective terminal alkyne dimerization at RT. However, later studies found that under reaction conditions, polymetallic core dissociates into mononuclear Cu and Pd, latter acting as a catalyst for alkyne dimerization.
3) We also finalized the project related to Ru complex with our ligand platform that features secondary coordination sphere interactions. This complex is active in catalytic benzyl alcohol acceptorless dehydrogenation.
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