A desilylative approach to alkyl substituted C(1)-ammonium enolates : application in enantioselective [2+2] cycloadditions
Date
12/09/2022Author
Funder
Grant ID
NF170330
Metadata
Show full item recordAltmetrics Handle Statistics
Altmetrics DOI Statistics
Abstract
The catalytic generation of C(1)-ammonium enolates from the corresponding α-silyl-α-alkyl substituted carboxylic acids using the isothiourea HyperBTM is reported. This desilylative approach grants access to α-unsubstituted and α-alkyl substituted C(1)-ammonium enolates, which are typically difficult to access through traditional methods reliant upon deprotonation. The scope and limitations of this process is established in enantioselective [2+2]-cycloaddition processes with perfluoroalkylketones (31 examples, up to 96% yield and >99:1 er), as well as selective [2+2]-cycloaddition with trifluoromethyl enones (4 examples, up to 75% yield and >99:1 er). Preliminary mechanistic studies indicate this process proceeds through an initial kinetic resolution of an in situ prepared (±)-α-silyl-α-alkyl substituted anhydride, while the reaction process exhibits overall pseudo zero-order kinetics.
Citation
Wang , Y , Young , C M , Liu , H , Hartley , W , Wienhold , M , Cordes , D B , Slawin , A M Z & Smith , A D 2022 , ' A desilylative approach to alkyl substituted C(1)-ammonium enolates : application in enantioselective [2+2] cycloadditions ' , Angewandte Chemie International Edition , vol. 61 , no. 38 , e202208800 . https://doi.org/10.1002/anie.202208800
Publication
Angewandte Chemie International Edition
Status
Peer reviewed
ISSN
1433-7851Type
Journal article
Rights
Copyright © 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH. 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: The research leading to these results has received funding from the CSC-St Andrews PhD Scholarship Scheme (Y.W.), the Newton Fellowship Programme (H.L.) and the Engineering and Physical Sciences Research Council, University of St Andrews, and the EPSRC Centre for Doctoral Training in Critical Resource Catalysis (CRITICAT) for financial support [Ph.D. studentship to W. H.; Grant code: EP/L016419/1].Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.