Ketenes react with various allylic halides mediated by 2 equiv samarium(II) diiodide (SmI2) to the ketenes to afford allylated ketones in good yields. In the reaction with γ-substituted allylic halides, the regioselectivity is influenced by the olefinic geometry of allylic halides. By using γ-substituted (E)-allylic halides, the allylation proceeds on the less hindered site (α-position) of allylic groups predominantly and the tendency was enhanced by the addition of HMPA.
在 2 等量的二
碘化钐(
SmI2)介导下,烯酮与各种烯丙基卤化物发生反应,生成烯丙基化酮,产率良好。在与γ-取代的烯丙基卤化物的反应中,区域选择性受到烯丙基卤化物的烯烃几何形状的影响。使用γ-取代的(E)-烯丙基卤化物时,烯丙基醛化主要在烯丙基受阻较小的位点(α-位)上进行,加入 HMPA 后,烯丙基醛化的趋势增强。