Light-mediated catalytic enantioselective difluoroalkylation of β-ketoesters via phase-transfer catalysis
Abstract
We report a phase-transfer-catalysed asymmetric α-difluoroalkylation of β-ketoesters through visible light-promoted radical generation. This methodology affords quaternary stereocentres with mild enantioenrichment and isolated yields up to 99%. Through mechanistic investigations, we have determined that the reaction proceeds via difluoroalkyl radical generation arising from an in situ electron donor-acceptor complex capable of absorbing visible light. Extensive optimisation of the reaction parameters was carried in an attempt to overcome a facile racemic background reaction.
Citation
Adams , C E & Johnston , C P 2024 , ' Light-mediated catalytic enantioselective difluoroalkylation of β-ketoesters via phase-transfer catalysis ' , Organic Chemistry Frontiers , vol. 11 , no. 13 , pp. 3639-3647 . https://doi.org/10.1039/d4qo00390j
Publication
Organic Chemistry Frontiers
Status
Peer reviewed
ISSN
2052-4110Type
Journal article
Description
The authors acknowledge funding from the Royal Society (University Research Fellowship URF\\R1\\180017 (CPJ)) and the University of St Andrews (CEA). We thank Yitong Wang for his help in the synthesis of starting materials and Reece Hoogesteger for running scale-up experiments. We thank Prof. Andy Smith, Prof. Allan Watson, and their respective research groups for sharing their lab equipment and chemical inventories.Collections
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