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
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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