Strictly Regiocontrolled α-Monosubstitution of Cyclic Carbonyl Compounds with Alkynyl and Alkyl Groups via Pd-Catalyzed Coupling of Cyclic α-Iodoenones with Organozincs
作者:Ei-ichi Negishi、Ze Tan、Show-Yee Liou、Baiqiao Liao
DOI:10.1016/s0040-4020(00)00864-4
日期:2000.12
derivatives readily undergo Pd-catalyzed cross coupling with α-iodoenones. Although (s-Bu)2Zn also undergoes Pd-catalyzed cross coupling, only the n-Bu-substituted products were obtained. α-Benzylation and α-homobenzylation can proceed satisfactorily, whereas allylzinc and propargylzinc derivatives undergo only addition to the carbonyl group. Although some promising results have been obtained in α-homoallylation
已优化了Pd催化的环状α-碘烯酮(如2-碘-2-环己烯酮)与炔基锌的交叉偶联条件。使用三(邻-呋喃基)膦(TFP)作为配体和使用DMF作为溶剂已导致以优异的产率形成α-炔基酮。该最优化的方法已用于高产率合成(±)-harveynone和(±)-tricholomenynA。对使用烷基锌的相关α-烷基化反应的研究揭示了以下内容。甲基锌和伯烷基锌衍生物容易与α-碘烯酮进行Pd催化的交叉偶联。尽管(s -Bu)2 Zn也经历Pd催化的交叉偶联,但只有n获得-Bu-取代的产物。α-苄基化和α-高苄基化可以令人满意地进行,而烯丙基锌和炔丙基锌衍生物仅在羰基上加成。尽管已经在α-均烯丙基化和α-均丙炔化中获得了一些有希望的结果,但是这些反应仍需要进一步改善。