Amine-borane dehydrogenation

The complex (13) reacts with H2 affording a dihydridoboratocobalt dihydride (14) in a reversible manner because of the boron ability to switch between a boryl and a dihydroborate conformation. The complex (14) reacts with HMe2N-BH3 to give a hydridoborane cobalt tetrahydridoborate complex (15), which is examined as the catalyst for olefin hydrogenation as well as amine-borane dehydrogenation/transfer hydrogenation. " " ... 

Fig. 16 Proposed mechanism of amine-borane dehydrogenation at group 2 centers...

Dehydrogenation of Amine Borane and Transfer Hydrogenation Using Amine Borane as a Hydrogen Source... 

One remarkable application of the Re(I) complexes of type 16-19 is the catalytic dehydrogenation of amine boranes [54], In recent years, the research on amine borane R R NH-BHs (R R = alkyl, H) became an important topic based on their capability of chemical hydrogen storage [55-57], In this respect transition metal-catalyzed dehydrocoupling reactions of amine borane offer great potential for control over both extent and rate of hydrogen release [58, 59]. 

In extension to the dehydrogenation studies of amine boranes and the transfer hydrogenations of alkenes catalyzed by the Re(I) complexes 16 and 17, highly efficient hydrogenations of alkenes were established based on the co-catalytic systems of 16/Me2NH-BH3 or 17/Lewis acid, which exhibited catalytic activities comparable to those of Wilkinson- or Schrock-Osbom-type hydrogenations accomplished with platinum group metal catalysts [24]. 

Scheme 5.10 Titanium-catalysed dehydrogenation reactions of amine-borane adducts.

Scheme 21 Catalytic dehydrogenation of amine boranes by a heterobimetallic Fe/Zr complex...

Scheme 28 Dehydrogenation of amine boranes catalyzed by Ti/Ru heterobimetallic complexes and proposed mechanism...

Mohajeri, N. Tabatabaie-Raissi, A. Bokerman, G., Catalytic dehydrogenation of amine borane complexes, U.S. Patent 7578992, 2009. 

APTS-Stabilized RuNPs for Dehydrogenation Reactions of Amine-Boranes. 347... 

Scheme 5 Dehydrogenation of secondary amine boranes at group 9 metal centers leading to the formation of a coordinated aminoborane (upper) ora linear borazane chain (lower). ...

See, for example, Alcaraz G, Sabo-Etienne S. Coordination and dehydrogenation of amine-boranes at metal centers. Angew Chem Int Ed Engl. 2010 49 7170-7179. 

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