2002 Fiscal Year Final Research Report Summary
The First a-Stannylation in the Hydrostannation of Aliphatic Alkynes
| Project/Area Number |
13650920
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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 | Osaka University |
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Principal Investigator |
SHIBATA Ikuya Osaka University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (10196420)
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| Project Period (FY) |
2001 – 2002
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| Keywords | tin hydride / ate complex / alkyne / Markovnikov addition / a-stannylation / viniy tins / regioselective reaction / highly selective reaction |
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| Research Abstract |
Hydrostannation of alkynes with tri-n-butyltin hydride is one of the simplest and direct routes to vinylstaniianes, which have great versatility as building blocks in synthesis. The control of regioselectivity in the hydrostannation is extraordinary important issue. Until now no effort has been reported so far for the selective a stannylation of aliphatic alkynes and it is apparent that a novel hydrostannation reagent is required for the formation of alpha-adduct. In the context of our studies on tin ate complexes, we have found a novel tin hydride complex, [MgBr]+[n-Bu_2SnBrIH]- (A) to give a-adducts 2 selectively in the hydrostannation of simple aliphatic alkynes. The structure of the ate complex was determined by ^<119>Sn NMR. The peak corresponding to n-Bu_2SnIH (-70.7 ppm) gradually shifted to -146.7 ppm until equimoler amount of MgBr2-OEt2 was added, and further addition caused no shift still more. The similar gradual increases in the coupling constant, 1j(^<119>Sn-1H) and 1J(^<119>Sn-^<13>C), were observed, from 2022 to 2304 Hz and from 382 to 500 Hz, respectively. These phenomena strongly indicate the formation of TBP type of 1:1 complex. These results support the idea that an ate complex directly promotes the a-stannylation.
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Research Products
(23 results)
