First Stereospecific Synthesis of (<i>E</i>)- or (<i>Z</i>)-α-Fluoroenones via a Kinetically Controlled Negishi Coupling Reaction
作者:Guillaume Dutheuil、Clotilde Paturel、Xinsheng Lei、Samuel Couve-Bonnaire、Xavier Pannecoucke
DOI:10.1021/jo0604787
日期:2006.5.1
A highly stereospecific synthesis of (E)- or (Z)-α-fluoro-α,β-unsaturated ketones 4, via a kinetically controlled Negishi palladium-catalyzed coupling reaction, was developed, providing an easy and general access to valuable fluorinated intermediates (pharmaceutical, peptide mimic, and so on). The synthesis involved a reaction between E/Z gem-bromofluoroolefins 2 and alkoxyvinylzinc species 6 under
通过动力学控制的Negishi钯催化的偶联反应,开发了高度立体定向合成(E)-或(Z)-α-氟-α,β-不饱和酮4的方法,可轻松,普遍地获得有价值的氟化中间体(药品,模拟肽等)。合成涉及在受控的反应温度下E / Z宝石-溴氟烯烃2与烷氧基乙烯基锌物种6之间的反应。在10°C下,可获得(Z)-4(70至99%的产率)和未反应的(Z)-2(66至99%的产率)。在THF回流下,将回收的烯烃转化为(E)-4(产率高达98%)。