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End date: 2019 × Start date: 2010 × Type: Text × Subject: alkoxycarbonylation × WGL Institute: LIKAT ×

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    Highly active and efficient catalysts for alkoxycarbonylation of alkenes
    ([London] : Nature Publishing Group UK, 2017) Dong, Kaiwu; Fang, Xianjie; Gülak, Samet; Franke, Robert; Spannenberg, Anke; Neumann, Helfried; Jackstell, Ralf; Beller, Matthias
    Carbonylation reactions of alkenes constitute the most important industrial processes in homogeneous catalysis. Despite the tremendous progress in this transformation, the development of advanced catalyst systems to improve their activity and widen the range of feedstocks continues to be essential for new practical applications. Herein a palladium catalyst based on 1,2-bis((tert-butyl(pyridin-2-yl)phosphanyl)methyl)benzene L3 (py t bpx) is rationally designed and synthesized. Application of this system allows a general alkoxycarbonylation of sterically hindered and demanding olefins including all kinds of tetra-, tri-and 1,1-disubstituted alkenes as well as natural products and pharmaceuticals to the desired esters in excellent yield. Industrially relevant bulk ethylene is functionalized with high activity (TON: >1,425,000; TOF: 44,000 h-1 for initial 18 h) and selectivity (>99%). Given its generality and efficiency, we expect this catalytic system to immediately impact both the chemical industry and research laboratories by providing a practical synthetic tool for the transformation of nearly any alkene into a versatile ester product.
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    Copper/iron co-catalyzed alkoxycarbonylation of unactivated alkyl bromides
    (London : Springer Nature, 2018) Li, Y.; Wu, X.-F.
    Carbonylative transformations of alkyl bromides have been explored less than those of aryl halides, in part because of the high barrier to activation of aryl bromides. Additionally, alkyl-metal reagents formed in situ can tend to undergo β-hydride elimination. Here we describe a copper/iron co-catalyzed alkoxycarbonylation of unactivated alkyl bromides. In the presence of catalytic quantities of iron and copper catalysts, primary, secondary, and tertiary alkyl bromides are carbonylatively transformed into the corresponding aliphatic esters in good yields. A potential reaction mechanism is proposed based on control experiments.