Amine-Borane Dehydrogenation and Transfer Hydrogenation Catalyzed by α-Diimine Cobaltates
Thomas M Maier1, Sebastian Sandl2,3, Ilya G Shenderovich2
1Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
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.
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