This work was financially supported by the NRW International Graduate School of Chemistry (stipend to R.C.S.) and the Deutsche Forschungsgemeinschaft (SFB 749). We thank Prof. Stefan Grimme for providing the infrastructure for this work.
Nucleophilic Addition of Enols and Enamines to α,β-Unsaturated Acyl Azoliums: Mechanistic Studies†
Article first published online: 13 APR 2012
Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Angewandte Chemie International Edition
Volume 51, Issue 21, pages 5234–5238, May 21, 2012
How to Cite
Samanta, R. C., Maji, B., De Sarkar, S., Bergander, K., Fröhlich, R., Mück-Lichtenfeld, C., Mayr, H. and Studer, A. (2012), Nucleophilic Addition of Enols and Enamines to α,β-Unsaturated Acyl Azoliums: Mechanistic Studies . Angew. Chem. Int. Ed., 51: 5234–5238. doi: 10.1002/anie.201109042
- Issue published online: 15 MAY 2012
- Article first published online: 13 APR 2012
- Manuscript Revised: 10 FEB 2012
- Manuscript Received: 21 DEC 2011
- acylazolium ions;
- N-heterocyclic carbenes;
- ucleophilic additions
1,4 but not 1,2! The reactivity of 1 towards different nucleophiles (deprotonated β-diketones, enamines, and malonodinitrile) was investigated by NMR and kinetic experiments. These investigations proved that CC bond formation occurs by a Michael-type 1,4-addition and not by a 1,2-addition and subsequent [3,3]-sigmatropic rearrangement. The first X-ray structure of an α,β-unsaturated acyl azolium salt (1) is also presented.