Journal
CHEMISTRY-A EUROPEAN JOURNAL
Volume 17, Issue 47, Pages 13308-13317Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/chem.201101725
Keywords
alcohols; alkylation; amines; borrowing hydrogen; imines
Categories
Funding
- National Basic Research Program of China [2009CB825300]
- National Natural Science Foundation of China
- 863 Program of China [2009AA063903]
- Chinese Academy of Sciences [DICP K2009D04]
Ask authors/readers for more resources
Versatile syntheses of secondary and tertiary amines by highly efficient direct N-alkylation of primary and secondary amines with alcohols or by deaminative self-coupling of primary amines have been successfully realized by means of a heterogeneous bimetallic PtSn/?-Al2O3 catalyst (0.5 wt?% Pt, Pt/Sn molar ratio=1:3) through a borrowing-hydrogen strategy. In the presence of oxygen, imines were also efficiently prepared from the tandem reactions of amines with alcohols or between two primary amines. The proposed mechanism reveals that an alcohol or amine substrate is initially dehydrogenated to an aldehyde/ketone or NH-imine with concomitant formation of a [PtSn] hydride. Condensation of the aldehyde/ketone species or deamination of the NH-imine intermediate with another molecule of amine forms an N-substituted imine which is then reduced to a new amine product by the in-situ generated [PtSn] hydride under a nitrogen atmosphere or remains unchanged as the final product under an oxygen atmosphere. The PtSn/?-Al2O3 catalyst can be easily recycled without Pt metal leaching and has exhibited very high catalytic activity toward a wide range of amine and alcohol substrates, which suggests potential for application in the direct production of secondary and tertiary amines and N-substituted imines.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available