Exploiting the imidazolium effect in base-free ammonium enolate generation : synthetic and mechanistic studies
Abstract
N-Acyl imidazoles and catalytic isothiourea hydrochloride salts function as ammonium enolate precursors in the absence of base. Enantioselective Michael addition-cyclization reactions using different α,β-unsaturated Michael acceptors have been performed to form dihydropyranones and dihydropyridinones with high stereoselectivity. Detailed mechanistic studies using RPKA have revealed the importance of the “imidazolium” effect in ammonium enolate formation and have highlighted key differences with traditional base-mediated processes.
Citation
Young , C M , Stark , D G , West , T H , Taylor , J E & Smith , A D 2016 , ' Exploiting the imidazolium effect in base-free ammonium enolate generation : synthetic and mechanistic studies ' , Angewandte Chemie International Edition , vol. 55 , no. 46 , pp. 14394-14399 . https://doi.org/10.1002/anie.201608046
Publication
Angewandte Chemie International Edition
Status
Peer reviewed
ISSN
1433-7851Type
Journal article
Rights
Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. This work is made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1002/anie.201608046
Description
The authors thank the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC Grant Agreement no. 279850 (CMY, THW, JET). ADS thanks the Royal Society for a Wolfson Merit Award.Collections
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