Silva Franck, Reiter Maud, Mills-Webb Rebecca, Sawicki Marcin, Klär Daniel, Bensel Nicolas, Wagner Alain, Gouverneur Véronique
Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
J Org Chem. 2006 Oct 27;71(22):8390-4. doi: 10.1021/jo061292a.
A novel palladium(II)-catalyzed oxy-carbopalladation process was developed allowing for the orchestrated union of hydroxy ynones with ethyl acrylate, two electron-deficient reactants. With beta-hydroxy ynones, this cascade Wacker-Heck process gave access to highly functionalized tri- or tetrasubstituted dihydropyranones featuring an unusual dienic system. For diastereomerically pure and for enantioenriched beta-hydroxyynones, these reactions proceed without affecting the stereochemical integrity of the existing stereocenters. In addition, tetrasubstituted furanones can be prepared when alpha-hydroxyynones and ethyl acrylate are used as starting materials. The dihydropyranones and furanones obtained upon cyclization are novel compounds, but structurally related carbohydrate derivatives featuring a similar dienic system have been used as starting materials for the construction of polyannulated products, suggesting that these cascade Pd(II)-mediated oxidative heterocyclizations are of value for various synthetic applications.
开发了一种新型钯（II）催化的氧-碳钯化过程，该过程能够使羟基炔酮与丙烯酸乙酯这两种缺电子反应物有序结合。对于β-羟基炔酮，这种串联的瓦克-赫克过程可得到具有不寻常双烯体系的高度官能化的三取代或四取代二氢吡喃酮。对于非对映体纯的和对映体富集的β-羟基炔酮，这些反应在不影响现有立体中心立体化学完整性的情况下进行。此外，当使用α-羟基炔酮和丙烯酸乙酯作为起始原料时，可以制备四取代呋喃酮。环化得到的二氢吡喃酮和呋喃酮是新型化合物，但具有类似双烯体系的结构相关碳水化合物衍生物已被用作构建多环产物的起始原料，这表明这些串联的钯（II）介导的氧化杂环化反应在各种合成应用中具有价值。
