Metallic Barium: A Versatile and Efficient Hydrogenation Catalyst

Stegner P, Färber C, Zenneck U, Knüpfer C, Eyselein J, Wiesinger M, Harder S (2020)

Publication Type: Journal article

Publication year: 2020

Journal

DOI: 10.1002/anie.202014326

Abstract

Ba metal was activated by evaporation and cocondensation with heptane. This black powder is a highly active hydrogenation catalyst for the reduction of a variety of unactivated (non-conjugated) mono-, di- and tri-substituted alkenes, tetraphenylethylene, benzene, a number of polycyclic aromatic hydrocarbons, aldimines, ketimines and various pyridines. The performance of metallic Ba in hydrogenation catalysis tops that of the hitherto most active molecular group 2 metal catalysts. Depending on the substrate, two different catalytic cycles are proposed. A: a classical metal hydride cycle and B: the Ba metal cycle. The latter is proposed for substrates that are easily reduced by Ba⁰, that is, conjugated alkenes, alkynes, annulated rings, imines and pyridines. In addition, a mechanism in which Ba⁰ and BaH2 are both essential is discussed. DFT calculations on benzene hydrogenation with a simple model system (Ba/BaH2) confirm that the presence of metallic Ba has an accelerating effect.

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How to cite

APA:

Stegner, P., Färber, C., Zenneck, U., Knüpfer, C., Eyselein, J., Wiesinger, M., & Harder, S. (2020). Metallic Barium: A Versatile and Efficient Hydrogenation Catalyst. Angewandte Chemie International Edition. https://doi.org/10.1002/anie.202014326

MLA:

Stegner, Philipp, et al. "Metallic Barium: A Versatile and Efficient Hydrogenation Catalyst." Angewandte Chemie International Edition (2020).

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