We thank the Swiss National Science Foundation (21-119750.01) and Prof. Dr. E. M. Carreira for generous financial support, Solvias AG for DTBM-MeObiphep, and Umicore AG & Co. KG for rhodium salts. N.C. is grateful to the Fonds der Chemischen Industrie for a Liebig Fellowship.
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Communication
Enantioselective C![[BOND]](http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8ff.gif)
C Bond Activation of Allenyl Cyclobutanes: Access to Cyclohexenones with Quaternary Stereogenic Centers†
Article first published online: 29 OCT 2008
DOI: 10.1002/anie.200804281
Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Issue
Angewandte Chemie International Edition
Volume 47, Issue 48, pages 9294–9297, November 17, 2008
Additional Information
How to Cite
Seiser, T. and Cramer, N. (2008), Enantioselective CC Bond Activation of Allenyl Cyclobutanes: Access to Cyclohexenones with Quaternary Stereogenic Centers. Angew. Chem. Int. Ed., 47: 9294–9297. doi: 10.1002/anie.200804281
- †
Publication History
- Issue published online: 12 NOV 2008
- Article first published online: 29 OCT 2008
- Manuscript Received: 29 AUG 2008
Funded by
- Swiss National Science Foundation. Grant Number: 21-119750.01
Keywords:
- asymmetric catalysis;
- CC activation;
- cyclobutanes;
- rhodium;
- ring expansion
Chiral rhodium(I) complexes activate allenyl tert-cyclobutanols efficiently through enantioselective insertion into a CC σ bond of the cyclobutane (see scheme; cod=1,5-cyclooctadiene, DTBM=3,5-di-tert-butyl-4-methoxyphenyl). Ring expansion by this method produced cyclohexenones with quaternary stereogenic centers with excellent enantioselectivity. The catalyst loading can be decreased to just 0.1 mol % in rhodium.