Palladium‐Catalyzed Oxidative Cascade Carbonylative Spirolactonization of Enallenols. Issue 12 (17th February 2017)

• Record Type: Journal Article
• Authors: Qiu, Youai; Yang, Bin; Jiang, Tuo; Zhu, Can; Bäckvall, Jan‐E.
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 12(2017)
• Page Start: 3221
• Page End: 3225
• Publication Date: 2017-02-17
• Subjects: carbocyclization -- enallenols -- oxidation -- palladium -- spirolactones; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201612384
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A highly selective palladium‐catalyzed oxidative carbonylation/carbocyclization/alkoxycarbonylation of enallenols to afford spirolactones bearing an all‐carbon quaternary center was developed. This transformation involves the overall formation of three C−C bonds and one C−O bond through a cascade insertion of carbon monoxide (CO), an olefin, and CO. Preliminary experiments on chiral anion‐induced enantioselective carbonylation/carbocyclization of enallenols afforded spirolactones with moderate enantioselectivity. Abstract : All together now : A highly selective cascade reaction for C−C/C−O bond formation through palladium‐catalyzed oxidative carbonylation/carbocyclization/alkoxycarbonylation of enallenols was developed, affording spirolactones bearing an all‐carbon quaternary center. Preliminary attempts to obtain enantioselectivity in the carbonylative carbocyclization revealed that the VAPOL‐type chiral phosphoric acid serves as a good anionic co‐catalyst in this transformation.