Back to Search
Start Over
Helicenes as Chirality-Inducing Groups in Transition-Metal Catalysis: The First Helically Chiral Olefin Metathesis Catalyst.
- Source :
-
Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2018 Aug 01; Vol. 24 (43), pp. 10994-10998. Date of Electronic Publication: 2018 Jul 06. - Publication Year :
- 2018
-
Abstract
- Helical chirality is a novel enantioselectivity-inducing property in transition-metal-catalyzed transformations. The principle is illustrated herein for the example of asymmetric olefin metathesis. This work reports the synthesis of the first helically chiral Ru-NHC alkylidene complex from an aminohelicene-derived imidazolium salt, which was ligated to the first generation Hoveyda-Grubbs catalyst. Kinetic data were acquired for benchmark test reactions and compared to an achiral catalyst. The helically chiral Ru-catalyst was evaluated in asymmetric ring-closing metathesis (RCM) and ring-opening metathesis-cross-metathesis (ROM/CM) reactions, which proceeded with promising levels of enantioselectivity. Extensive NMR-spectroscopic investigations and a DFT geometry optimization were performed. These results led to a topographic steric map and calculation of percent-buried-volume values for each quadrant around the metal center.<br /> (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Details
- Language :
- English
- ISSN :
- 1521-3765
- Volume :
- 24
- Issue :
- 43
- Database :
- MEDLINE
- Journal :
- Chemistry (Weinheim an der Bergstrasse, Germany)
- Publication Type :
- Academic Journal
- Accession number :
- 29917281
- Full Text :
- https://doi.org/10.1002/chem.201802786