Protic additives or impurities promote imine reduction with pinacolborane
作者:Blake S. N. Huchenski、Alexander W. H. Speed
DOI:10.1039/c8ob02330a
日期:——
enantioinduction. While the reactions described herein are not competitive in conversion with established imine reduction technologies, this work reveals that the presence of protic impurities must be considered as a promoter of side reactions in catalyzed imine hydroborations. Amines also promote imine reduction in certain cases, raising the possibility of a slow autocatalytic reaction. The ability of water
Hydroboration Catalyzed by 1,2,4,3-Triazaphospholenes
作者:Chieh-Hung Tien、Matt R. Adams、Michael J. Ferguson、Erin R. Johnson、Alexander W. H. Speed
DOI:10.1021/acs.orglett.7b02695
日期:2017.10.20
shown to catalyze the 1,2 hydroboration of 19 imines, and three α,β unsaturated aldehydes with pinacolborane, including examples that did not undergo hydroboration by previously reported diazaphospholene systems. DFT calculations support a mechanism where a triazaphospholene cation interacts with the substrate, a mechanism distinct from diazaphospholene catalyzed hydroborations.
Diazaphospholene Precatalysts for Imine and Conjugate Reductions
作者:Matt R. Adams、Chieh-Hung Tien、Blake S. N. Huchenski、Michael J. Ferguson、Alexander W. H. Speed
DOI:10.1002/anie.201611570
日期:2017.5.22
The first examples of 1,3,2-diazaphospholene-catalyzed iminereduction and conjugate reduction reactions are reported. This approach employs readily synthesized alkoxydiazaphospholene precatalysts that can be handled in open air. Reduction of substrates containing Lewis basic functionality, isolated unsaturation, and protic functional groups was accomplished. The synthetic utility of this approach
Solvent-free reductiveamination of aldehydes and ketones with aliphatic and aromatic amines in high-to-excellent yields has been achieved with sub-stoichiometric trimethyl borate as promoter and ammonia borane as reductant.
The present invention relates to processes for the preparation of rasagiline mesylate. Also provided is rasagiline mesylate having 90 volume percent of the particles (D
90
) with sizes less than about 6 μm and processes for the preparation thereof.