SELECTIVE REDUCTION OF ALKENES AND ALKYNES BY REAGENT LITHIUM ALUMINUM HYDRIDE TRANSITION-METAL HALIDE
SELECTIVE REDUCTION OF ALKENES AND ALKYNES BY REAGENT LITHIUM ALUMINUM HYDRIDE TRANSITION-METAL HALIDE
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DOI：
10.1021/jo00407a004
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发表时间：
1978-01-01
影响因子：
3.6
通讯作者：
LIN, JJ
中科院分区：
文献类型：
--
作者：
ASHBY, EC;LIN, JJ
本文详细研究了L1AlH4与第一排过渡金属卤化物的混合体系中烯、炔与L1AlH4的反应。当L1AlH4与T1Cl3、VC13、CrCl3、FeCl2、FeCl3、CoCl2或NiCl2等摩尔量混合时，烯烃被还原为相应的烷烃。但在催化剂用量较大的情况下，只有CoCl2、NiCl2和TiCl3能高效地将烯烃还原为烷烃。1-甲基环己烯(一种三取代烯烃)在氢化锆化或LiAlH4-TiCl3还原效果很差的情况下，被LiAlH4-CoCl2和LiAlH4-NiCl2还原。在与LiAlH4的混合物中，一种或多种过渡金属卤化物将下列烯烃还原为相应的烷烃：1-辛烯、1-己烯、顺-2-己烯、反式-2-己烯、苯乙烯、环己烯和2-乙基己烯。以LiAlH4-FeCl2为催化剂将苯乙炔定量还原为苯乙烯，以LiAlH4-NiCl2为催化剂将苯乙炔定量还原为乙苯。在没有反式二苯乙烯的情况下，LiAlH4-NiCl2可以将二苯乙炔还原为顺式二苯乙烯。LiAlH4-FeCl2可将1-辛烯定量还原为辛烷，LiAlH4-NiCl2可将1-辛烯定量还原为1-辛烯。氚掺入研究表明，在这些反应中形成的中间过渡金属烷基是不稳定的，因为除TiCl3作为催化剂外，仅观察到12-47%的氚掺入。
The react ions of alkenes and alkynes with L1AIH4 inadmixture with first-row transition-metal halides have been studied in detail. When L1AIH4 and T1CI3, VC13, CrCl3, FeCl2, FeCl3, CoCl2, or NiCl2 were mixed in equimolar quantities, alkenes were reduced inquantitative yield to the corresponding alkanes. However, when the transitionmetal halide was used in catalytic amount, only CoCl2, NiCl2, and TiCl3 were effective in reducing olefins to alkanes in high yield. 1-Methylcyclohexene (a trisubstituted olefin), which is reduced only poorly by hydrozirconation or LiAlH4-TiCl3, was reduced inquantitative yield by LiAlH4-CoCl2 and LiAlH4-NiCl2. The following olefins were reduced to the corresponding alkanes in quantitative yield by one or more transition-metal halides in admixture with LiAlH4: 1-octene, 1-hexene, cis-2-hexene, trans-2-hexene, styrene, cyclohexene, and 2-ethylhexene. Phenylacetylene was reduced quantitatively to styrene using LiAlH4-FeCl2 or to ethylbenzene when LiAlH4-NiCl2 was used. Diphenylacetylene could be reduced to cis-stilbene in the absence of trans-stilbene by LiAlH4-NiCl2. 1-Oct-yne could be reduced to octane in quantitative yield by LiAlH4-FeCl2 or to 1-octeneby LiAlH4-NiCl2. Deuterium incorporation studies indicate that the intermediate transition-metal alkyls formed in these reactions are not sta-ble, as only 12-47% deuterium incorporation is observed except when TiCl3 is used as the catalyst.