Transition Metal-Catalyzed Addition Reaction to Alkynylmetals with Migration of Metal Moieties
| Project/Area Number |
17550100
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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 | Kyoto University |
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Principal Investigator |
SHIRAKAWA Eiji Kyoto University, Graduate School of Science, Associate Professor, 大学院理学研究科, 助教授 (70273472)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | transition metal catalyst / alkynylmetal / addition reaction / ruthenium / alkyne / alkynylstannane |
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| Research Abstract |
In the presence of a catalytic amount of a ruthenium complex coordinated with PBu_3, alkynylstannanes (R^1C≡CSnBu_3) were found to accept the addition of terminal alkynes (R^2C=CH) with 1, 2-shift of the stannyl group to give (E)-and (Z)-1-tributylstannylbut-1-en-3-ynes (Bu_3SnC(R^1)=CHC=CR^2). The addition reaction is applicable to various combination of substrates having an aromatic and/or aliphatic substituent, the stereochemical outcome depending largely on the character of these substituents. The reaction of aliphatic terminal alkynes proceeds in perfect stereoselectivities, where substituent R^1 on alkynylstannanes determines the configuration : E for R^1 = alkyl and Z for R^1 = aryl. In contrast, the reaction of arylacetylenes gave a mixture of stereoisomers irrespective of the character of substituent R^1 on the alkynylstannane. Ruthenium-β-stannylvinylidene complexes generated from a ruthenium complex and an alkynylstannane with migration of the stannyl group is likely to be involved in the reaction as key intermediates, which accept addition of a C-H bond of terminal alkynes to give the corresponding stannylenynes. DFT calculation clearly shows that the 1, 2-shift of the stannyl group on formation of ruthenium-β-stannylvinylidene complexes is more facile than the corresponding 1, 2-hydrogen shift of the coordinating terminal alkynes. The effect of substituents on the stereoselectivity also is discussed based on the calculation.
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Report
(3 results)
Research Products
(4 results)
