Projects per year
Abstract
An isothiourea-catalysed Michael addition-annulation process using β-fluoroalkyl-substituted α,β-unsaturated aryl esters and a range of 2-acylbenzazoles is reported for the enantioselective synthesis of dihydropyranone and dihydropyridinone products bearing polyfluorinated stereocentres (29 examples, up to 98% yield, > 99:1 er). The choice of aryl group of the aryl ester proved essential in determining reaction enantioselectivity and dihydropyranone:dihydropyridinone product selectivity. The aryloxide leaving group is shown to play a number of essential additional roles, operating (i) as a Brønsted base, circumventing the need for an auxiliary base; and (ii) as a Lewis base to catalyse the isomerisation of dihydropyranone products into thermodynamically-favoured dihydropyridinones. After optimisation, this isomerisation process was exploited for the selective synthesis of dihydropyridinone products using acylbenzothiazoles, and either dihydropyranone or dihydropyridinone products using acylbenzoxazoles. Finally, the phenol derivative, produced following protonation of the aryloxide, is proposed to act as a Brønsted acid, which promotes an isothiourea-catalysed kinetic resolution of benzoxazole-derived dihydropyranones.
Original language | English |
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Pages (from-to) | 4909-4918 |
Number of pages | 10 |
Journal | Chemical Science |
Volume | 9 |
Issue number | 21 |
Early online date | 4 May 2018 |
DOIs | |
Publication status | Published - 7 Jun 2018 |
Fingerprint
Dive into the research topics of 'Multiple roles of aryloxide leaving groups in enantioselective annulations employing α,β-unsaturated acyl ammonium catalysis'. Together they form a unique fingerprint.Projects
- 2 Finished
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RS Wolfson Merit Award: Developing Catalysis Research: New Reaction Discoveries and Practical Applications
Smith, A. D. (PI)
1/01/15 → 31/12/19
Project: Fellowship
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ERC Starting Grant EnolCat: Emulating nature: Reaction diversity and understanding through asymmetric catalysis
Smith, A. D. (PI)
1/10/11 → 30/06/17
Project: Standard
Profiles
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Andrew David Smith
- School of Chemistry - Professor, Director of Research
- Biomedical Sciences Research Complex
- EaSTCHEM
Person: Academic
Datasets
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Multiple roles of aryloxide leaving groups in enantioselective annulations employing α,β-unsaturated acyl ammonium catalysis (dataset 2)
Greenhalgh, M. D. (Creator), Slawin, A. M. Z. (Creator) & Smith, A. D. (Creator), Cambridge Crystallographic Data Centre, 2018
https://dx.doi.org/10.5517/ccdc.csd.cc1zbmdb and one more link, https://dx.doi.org/10.5517/ccdc.csd.cc1zbmfc (show fewer)
Dataset
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data underpinning "Multiple roles of aryloxide leaving groups in enantioselective annulations employing a,b-unsaturated acyl ammonium catalysis"
Smith, A. D. (Creator), Greenhalgh, M. D. (Creator) & Qu, S. (Creator), University of St Andrews, 15 May 2018
DOI: 10.17630/2dec867e-570d-4bcc-99ba-2cefe7479357
Dataset
File