Journal article
Bifunctional rhenium complexes for the catalytic transfer-hydrogenation reactions of ketones and imines.
- Landwehr A Institute of Inorganic Chemistry, University of Zurich, Switzerland.
- Dudle B
- Fox T
- Blacque O
- Berke H
- 2012-03-29
Published in:
- Chemistry (Weinheim an der Bergstrasse, Germany). - 2012
English
The silyloxycyclopentadienyl hydride complexes [Re(H)(NO)(PR(3))(C(5)H(4)OSiMe(2)tBu)] (R=iPr (3 a), Cy (3 b)) were obtained by the reaction of [Re(H)(Br)(NO)(PR(3))(2)] (R=iPr, Cy) with Li[C(5)H(4)OSiMe(2)tBu]. The ligand-metal bifunctional rhenium catalysts [Re(H)(NO)(PR(3))(C(5)H(4)OH)] (R=iPr (5 a), Cy (5 b)) were prepared from compounds 3 a and 3 b by silyl deprotection with TBAF and subsequent acidification of the intermediate salts [Re(H)(NO)(PR(3))(C(5)H(4)O)][NBu(4)] (R=iPr (4 a), Cy (4 b)) with NH(4)Br. In nonpolar solvents, compounds 5 a and 5 b formed an equilibrium with the isomerized trans-dihydride cyclopentadienone species [Re(H)(2)(NO)(PR(3))(C(5)H(4)O)] (6 a,b). Deuterium-labeling studies of compounds 5 a and 5 b with D(2) and D(2)O showed H/D exchange at the H(Re) and H(O) positions. Compounds 5 a and 5 b were active catalysts in the transfer hydrogenation reactions of ketones and imines with 2-propanol as both the solvent and H(2) source. The mechanism of the transfer hydrogenation and isomerization reactions was supported by DFT calculations, which suggested a secondary-coordination-sphere mechanism for the transfer hydrogenation of ketones.
- Language
-
- English
- Open access status
- closed
- Identifiers
-
- DOI 10.1002/chem.201103685
- PMID 22454240
- Persistent URL
- https://roar.hep-bejune.ch/global/documents/255069
Statistics
Document views: 19
File downloads: