Migratory Hydrogenation of Terminal Alkynes by Base/Cobalt Relay Catalysis

• Published in: Angewandte Chemie Vol. 132; no. 17; pp. 6816 - 6821
• Main Authors: Liu, Xufang, Liu, Bingxue, Liu, Qiang
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 20.04.2020
• Subjects: Alkenes; Alkine; Alkynes; Catalysis; Chemical synthesis; Chemistry; Cobalt; Hydrierung; Hydrogenation; Intermediates; Isomerisierungen; Isomerization; Molecular chains; Noble metals; Relay; Stereoselectivity; Substrates; Synthesemethoden
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201916014

Migratory functionalization of alkenes has emerged as a powerful strategy to achieve functionalization at a distal position to the original reactive site on a hydrocarbon chain. However, an analogous protocol for alkyne substrates is yet to be developed. Herein, a base and cobalt relay catalytic process for the selective synthesis of (Z)‐2‐alkenes and conjugated E alkenes by migratory hydrogenation of terminal alkynes is disclosed. Mechanistic studies support a relay catalytic process involving a sequential base‐catalyzed isomerization of terminal alkynes and cobalt‐catalyzed hydrogenation of either 2‐alkynes or conjugated diene intermediates. Notably, this practical non‐noble metal catalytic system enables efficient control of the chemo‐, regio‐, and stereoselectivity of this transformation. Eine gestaffelte Base‐ und Cobalt‐Katalyse ermöglicht die selektive Synthese von (Z)‐2‐Alkenen und konjugierten (E)‐Alkenen durch migratorische Hydrierung von terminalen Alkinen. Die entsprechenden terminalen Alkene können ebenfalls unter leicht abgewandelten Reaktionsbedingungen erhalten werden. Die Produkte entstehen mit hohen Chemo‐, Regio‐ und Stereoselektivitäten.