Isothiourea-catalyzed functionalization of pyrrolyl- and indolylacetic acid : enantioselective synthesis of dihydropyridinones and one-pot synthesis of pyridinones
Abstract
A protocol for the isothiourea‐catalyzed enantioselective functionalization of pyrrolyl‐ and indolylacetic acids has been developed. Stereodefined dihydropyridinones are accessed through formal [4+2] cycloaddition of an in situ generated isothiouronium enolate with α,β‐unsaturated ketimines. The dihydropyridinones are obtained in moderate to excellent yield (26–97%), excellent diastereocontrol (all >95 : 5 dr) and moderate to excellent enantiocontrol (75 : 25–99 : 1 er). An unusual elimination of pyrrole or indole from the dihydropyridinone to access achiral pyridinones was observed and could be selectively promoted. A further one‐pot synthesis using an acyl imidazole was developed to give pyridinones in good to excellent yields (67–91%).
Citation
Zhang , S , Bacheley , L , Young , C M , Stark , D G , O'Riordan , T , Slawin , A M Z & Smith , A D 2020 , ' Isothiourea-catalyzed functionalization of pyrrolyl- and indolylacetic acid : enantioselective synthesis of dihydropyridinones and one-pot synthesis of pyridinones ' , Asian Journal of Organic Chemistry , vol. 9 , no. 10 , pp. 1562-1566 . https://doi.org/10.1002/ajoc.202000290
Publication
Asian Journal of Organic Chemistry
Status
Peer reviewed
ISSN
2193-5815Type
Journal article
Rights
Copyright © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Description
Funding: ERC under the European Union's Seventh Framework Programme (FP7/2007–2013) / ERC grant agreement no 279850. We thank Syngenta and EPSRC grant No. EP/K503162/1 (DGS), ADS thanks the Royal Society for a Wolfson Research Merit Award.Collections
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