Vinylic SN2 Reaction of 1-Decenyliodonium Salt with Halide Ions.
Vinylic SN2 Reaction of 1-Decenyliodonium Salt with Halide Ions.
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1-癸烯基碘鎓盐与卤化物离子的乙烯基 SN2 反应。
DOI：
10.1002/chin.199818081
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
M. Ochiai
中科院分区：
文献类型：
--
作者：
T. Okuyama;T. Takino;Koichiro Sato;K. Oshima;Shohei Imamura;H. Yamataka;T. Asano;M. Ochiai
在不同条件下研究了(E)-1-癸烯基(苯基)碘盐与卤化物离子的反应。产物是取代和消除的产物，通常是(Z)-1-卤代-1-癸烯和1-Decyne，以及碘苯，但与氟化物的反应仅导致消除。标记实验表明，氟引起的消除是通过α方式进行的，而其他卤化物引起的消除是同步β消除。动力学结果表明，取代和β消除主要发生在卤代λ3-碘烷中间体上，取代反应为与外部卤化物离子的双分子反应，消除反应为单分子(分子内)反应。UV光谱也证实了高价λ、3-碘烷和碘酸盐的中间体。二次动力学同位素效应、离基取代基效应和压力效应对反应速率的影响符合面内乙烯基SN2取代反应机理。
Reactions of (E)-1-decenyl(phenyl)iodonium salt with halide ions are examined under various conditions. The products are those of substitution and elimination, usually (Z)-1-halo-1-decene and 1-decyne, as well as iodobenzene, except for the reaction with fluoride which leads exclusively to elimination. The labeling experiments show that the elimination induced by fluoride occurs via an α mode, while that caused by the other halides is a syn β elimination. Kinetic results show that the substitution and β elimination occur mainly from the halo-λ3-iodane intermediate; the substitution occurs as a bimolecular reaction with the external halide ion while the elimination is a unimolecular (intramolecular) reaction. The intermediacy of the hypervalent λ3-iodane as well as of the iodate are also confirmed by UV spectroscopy. The secondary kinetic isotope effects, leaving group substituent effects, and pressure effects on the rate are compatible with the in-plane vinylic SN2 mechanism for the substitution with inve...