Cobalt-catalyzed intermolecular [2+2+2] cycloaddition for the synthesis of 1,3-cyclohexadienes
Cobalt-catalyzed intermolecular [2+2+2] cycloaddition for the synthesis of 1,3-cyclohexadienes
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DOI：
10.1021/jo800735x
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发表时间：
2008-07-04
影响因子：
3.6
通讯作者：
Harms, Klaus
中科院分区：
文献类型：
--
作者：
Hilt, Gerhard;Paul, Anna;Harms, Klaus
当使用丁炔酸甲酯时，内部受体取代的炔和末端烯烃之间的钴（I）催化的[2 + 2 + 2]环加成反应导致以可接受的产率形成区域化学富集的多取代的1，3-环己二酮衍生物，而由丙酸苯酯以良好的产率形成区域化学纯的产物。炔到相应苯衍生物的同时环三聚反应取决于炔的空间体积，并且随着空间位阻更大的炔而大大减少。
A cobalt(I)-catalyzed [2 + 2 + 2] cycloaddition reaction between an internal acceptor-substituted alkyne and a terminal alkene leads to the formation of regiochemically enriched polysubstituted 1,3-cyclohexadione derivatives in acceptable yields when methyl butynoate is used, whereas regiochemically pure products are formed in good yields form phenyl propyonate. The concurrent cyclotrimerization reaction of the alkyne to the corresponding benzene derivative is dependent on the sterical bulk of the alkyne and is considerably reduced with the sterically more hindered alkyne.