An Alkene‐Promoted Borane‐Catalyzed Highly Stereoselective Hydrogenation of Alkynes to Give Z‐ and E‐Alkenes. Issue 8 (14th January 2015)

• Record Type: Journal Article
• Authors: Liu, Yongbing; Hu, Lianrui; Chen, Hui; Du, Haifeng
• Is Part Of: Chemistry. Volume 21:Issue 8(2015)
• Page Start: 3495
• Page End: 3501
• Publication Date: 2015-01-14
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201405388
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The stereoselective hydrogenation of alkynes to alkenes is an extremely useful transformation in synthetic chemistry. Despite numerous reports for the synthesis of <italic>Z</italic>‐alkenes, the hydrogenation of alkynes to give <italic>E</italic>‐alkenes is still not well resolved. In particular, selective preparation of both <italic>Z</italic>‐ and <italic>E</italic>‐alkenes by the same catalytic hydrogenation system using molecular H₂ has rarely been reported. In this paper, a novel strategy of using simple alkenes as promoters for the HB(C₆F₅)₂‐catalyzed metal‐free hydrogenation of alkynes was adopted. Significantly, both <italic>Z</italic>‐ and <italic>E</italic>‐alkenes can be furnished by hydrogenation with molecular H₂ in high yields with excellent stereoselectivities. Further experimental and theoretical mechanistic studies suggest that interactions between H and F atoms of the alkene promoter, borane intermediate, and H₂ play an essential role in promoting the hydrogenolysis reaction.</p> </abstract>