Bicyclic Cyclopentenones via the Combination of an Iridium- Catalyzed Allylic Substitution with a Diastereoselective Intramolecular Pauson-Khand Reaction
作者:Andreas Farwick、Jens U. Engelhart、Olena Tverskoy、Carolin Welter、Quendolin A. Umlauf née Stang、Frank Rominger、William J. Kerr、Günter Helmchen
DOI:10.1002/adsc.201000706
日期:2011.2.11
Enantioselective syntheses of bicyclic cyclopentenones are described. Key steps are an iridium-catalyzed allylic substitution and an intramolecular diastereoselective Pauson–Khand reaction. The diastereoselectivity of the Pauson–Khand reaction was found to be crucially dependent on the unit connecting the propargylic and the olefinic parts of the precursor. Very high degrees of diastereoselection were
描述了双环环戊烯酮的对映选择性合成。关键步骤是铱催化的烯丙基取代和分子内非对映选择性的Pauson-Khand反应。发现鲍森-汉德反应的非对映选择性主要取决于连接前体的炔丙基和烯烃部分的单元。使用NBoc单元作为连接器可获得非常高的非定向变形度。通过在(-)-α-海藻酸的对映选择性正式全合成中的应用说明了该方法。