Amine-Borane Dehydrogenation and Transfer Hydrogenation Catalyzed by α-Diimine Cobaltates

Thomas M Maier; Sebastian Sandl; Ilya G Shenderovich; Axel Jacobi von Wangelin; Jan J Weigand; Robert Wolf

doi:10.1002/chem.201804811

Amine-Borane Dehydrogenation and Transfer Hydrogenation Catalyzed by α-Diimine Cobaltates

Chemistry. 2019 Jan 2;25(1):238-245. doi: 10.1002/chem.201804811. Epub 2018 Dec 11.

Authors

Thomas M Maier¹, Sebastian Sandl^{2

3}, Ilya G Shenderovich², Axel Jacobi von Wangelin^{2

3}, Jan J Weigand⁴, Robert Wolf¹

Affiliations

¹ Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
² University of Regensburg, Institute of Organic Chemistry, 93040, Regensburg, Germany.
³ Current address: University of Hamburg, Department of Chemistry, 20146, Hamburg, Germany.
⁴ TU Dresden, Faculty of Chemistry and Food Chemistry, Chair of Inorganic Molecular Chemistry, 01062, Dresden, Germany.

PMID: 30378191
DOI: 10.1002/chem.201804811

Abstract

Anionic α-diimine cobalt complexes, such as [K(thf)_1.5 {(^Dipp BIAN)Co(η⁴ -cod)}] (1; Dipp=2,6-diisopropylphenyl, cod=1,5-cyclooctadiene), catalyze the dehydrogenation of several amine-boranes. Based on the excellent catalytic properties, an especially effective transfer hydrogenation protocol for challenging olefins, imines, and N-heteroarenes was developed. NH₃ BH₃ was used as a dihydrogen surrogate, which transferred up to two equivalents of H₂ per NH₃ BH₃ . Detailed spectroscopic and mechanistic studies are presented, which document the rate determination by acidic protons in the amine-borane.

Keywords: amine-boranes; catalysis; cobalt; dehydrogenation; transfer hydrogenation.

Abstract

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