1998 Fiscal Year Final Research Report Summary
Studies on catalysts for selective functionalization of Group 14 compounds
| Project/Area Number |
09650953
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | HOKKAIDO UNIVERSITY (1998)
Gifu University (1997) |
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Principal Investigator |
TSUJI Yasushi Catalysis Research Center, Hokkaido Univ., Pro., 触媒化学研究センター, 教授 (30144330)
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| Project Period (FY) |
1997 – 1998
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| Keywords | functionalization / cyanation / palladium catalyst / catalyst species / oxidative addition / fluxional |
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| Research Abstract |
Allylic carbonates are cyanated in high yields to beta, gamma-unsaturated carbonitriles using trimethylsilyl cyanide in the presence of catalytic amount (5 mol%) of Pd(PPh_3)_4 in THF under reflux. The cyanations of several cis- and trans-alicyclic substrates proceed cleanly (stereoselectivity> 99%) with overall retention. Characterization and reaction of palladium complexes relevant to the present catalysis indicate that transmetallation of eta^3-allyl palladium complex with trimethylsilyl cyanide is facile, while the resulting cyano(eta^3-allyl)palladium complexes afford the corresponding allylic cyanides only when excess trimethylsilyl cyanide is present. Stereochemistry of the product indicates that the CN attacks the eta^3-allyl moieties from the palladium side.
The structures and fluxional behavior of two cis-bis(silyl)bis(phosphine)platinum complex, cis- [Pt(SiPh_2Me)_2(PMe_2Ph)_2] and cis-[Pt(SiFMe_2)_2(PEt_3)_2], and two cis-bis(stannyl)bis(phosphine)palladium complex, cis-[Pd(SnMe_3)_2(PMe_3)_2] and cis-[Pd(SnMe_3)_2(PMePh_2)_2], were examined, The complexes have twisted square-planar structures with cis-orientation of the ligands. The bis(silyl)platinum complexes show fluxional behavior on the NMR time-scale. In the fluxional process, the spin-spin coupling between P, Si, and Pt are retained ; namely these nuclear spin states are intramolecularly conserved. The fluxionality of the complexes is attributed to the unimolecular twist-rotation via pseudo tetrahedral transition state. Similar fluxionality of the bis(stannyl)palladium complex is evident by utilizing both solution and solid state ^<31>P NMR.
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Research Products
(4 results)
