Journal article

Publication year: 2020

Pages: 1590-1594

Journal: Angewandte Chemie International Edition

Volume number: 59

Issue number: 4

ISSN: 1433-7851

eISSN: 1521-3773

Open access status: Hybrid

DOI Link: https://doi.org/10.1002/anie.201910636

Publisher: Wiley

Abstract: 
Dehydrogenation of ammonia borane by sterically encumbered pyridones as organocatalysts is reported. With 6-tert-butyl-2-thiopyridone as the catalyst, a turnover frequency (TOF) of 88 h(-1) was achieved. Experimental mechanistic investigations, substantiated by DLPNO-CCSD(T) computations, indicate a mechanistic scenario that commences with the protonation of a B-H bond by the mercaptopyridine form of the catalyst. The reactive intermediate formed by this initial protonation was observed by NMR spectroscopy and the molecular structure of a surrogate determined by SCXRD. An intramolecular proton transfer in this intermediate from the NH3 group to the pyridine ring with concomitant breaking of the S-B bond regenerates the thiopyridone and closes the catalytic cycle. This step can be described as an inorganic retro-ene reaction.

Harvard Citation style: Hasenbeck, M., Becker, J. and Gellrich, U. (2020) Efficient Organocatalytic Dehydrogenation of Ammonia Borane, Angewandte Chemie International Edition, 59(4), pp. 1590-1594. https://doi.org/10.1002/anie.201910636

APA Citation style: Hasenbeck, M., Becker, J., & Gellrich, U. (2020). Efficient Organocatalytic Dehydrogenation of Ammonia Borane. Angewandte Chemie International Edition. 59(4), 1590-1594. https://doi.org/10.1002/anie.201910636