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Jesani MH, Schwarz M, Kim S, Evans FL, White A, Browning A, Abrams R, Clayden J. Selective defluorination of trifluoromethyl substituents by conformationally induced remote substitution. Angew Chem Int Ed Engl 2024:e202403477. [PMID: 38587304 DOI: 10.1002/anie.202403477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/28/2024] [Accepted: 04/02/2024] [Indexed: 04/09/2024]
Abstract
The selective reduction of an aromatic trifluoromethyl substituent to a difluoromethyl substituent may be achieved by base-promoted elimination to form a difluoro-p-quinomethide which is trapped by an intramolecular nucleophile. High yields are obtained when the nucleophilic trap entails the conformationally favoured cyclisation of an aminoisobutyric acid (Aib) derivative. The resulting cyclised difluoromethyl-substituted arylimidazolidinone products are readily converted to versatile difluoromethyl-substituted aldehydes by reduction and hydrolysis. Defluorination is successful on a range of benzenoid (both para and ortho CF3 substituted) and heterocyclic substrates. Double defluorination may likewise be achieved sequentially, or in a single step from an Aib dipeptide derivative.
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Affiliation(s)
- Mehul H Jesani
- University of Bristol, School of Chemistry, UNITED KINGDOM
| | - Maria Schwarz
- University of Bristol, School of Chemistry, UNITED KINGDOM
| | - Shiwhu Kim
- University of Bristol, School of Chemistry, UNITED KINGDOM
| | - Finlay L Evans
- University of Bristol, School of Chemistry, UNITED KINGDOM
| | | | - Alex Browning
- University of Bristol, School of Chemistry, UNITED KINGDOM
| | - Roman Abrams
- University of Bristol, School of Chemistry, UNITED KINGDOM
| | - Jonathan Clayden
- University of Bristol, School of Chemistry, Cantock's Close, BS8 1TS, Bristol, UNITED KINGDOM
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Basran J, Booth ES, Campbell LP, Thackray SJ, Jesani MH, Clayden J, Moody PCE, Mowat CG, Kwon H, Raven EL. Binding of l-kynurenine to X. campestris tryptophan 2,3-dioxygenase. J Inorg Biochem 2021; 225:111604. [PMID: 34571402 DOI: 10.1016/j.jinorgbio.2021.111604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/31/2021] [Accepted: 09/10/2021] [Indexed: 11/18/2022]
Abstract
The kynurenine pathway is the major route of tryptophan metabolism. The first step of this pathway is catalysed by one of two heme-dependent dioxygenase enzymes - tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO) - leading initially to the formation of N-formylkynurenine (NFK). In this paper, we present a crystal structure of a bacterial TDO from X. campestris in complex with l-kynurenine, the hydrolysed product of NFK. l-kynurenine is bound at the active site in a similar location to the substrate (l-Trp). Hydrogen bonding interactions with Arg117 and the heme 7-propionate anchor the l-kynurenine molecule into the pocket. A mechanism for the hydrolysis of NFK in the active site is presented.
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Affiliation(s)
- Jaswir Basran
- Department of Molecular and Cell Biology, Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester LE1 9HN, UK
| | - Elizabeth S Booth
- Department of Chemistry, Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Laura P Campbell
- EastChem School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Sarah J Thackray
- EastChem School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Mehul H Jesani
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Jonathan Clayden
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Peter C E Moody
- Department of Molecular and Cell Biology, Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester LE1 9HN, UK
| | - Christopher G Mowat
- EastChem School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Hanna Kwon
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Emma L Raven
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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Abrams R, Jesani MH, Browning A, Clayden J. Triarylmethanes and their Medium-Ring Analogues by Unactivated Truce-Smiles Rearrangement of Benzanilides. Angew Chem Int Ed Engl 2021; 60:11272-11277. [PMID: 33830592 PMCID: PMC8252078 DOI: 10.1002/anie.202102192] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/01/2021] [Indexed: 12/17/2022]
Abstract
Intramolecular nucleophilic aromatic substitution (Truce–Smiles rearrangement) of the anions of 2‐benzyl benzanilides leads to triarylmethanes in an operationally simple manner. The reaction succeeds even without electronic activation of the ring that plays the role of electrophile in the SNAr reaction, being accelerated instead by the preferred conformation imposed by the tertiary amide tether. The amide substituent of the product may be removed or transformed into alternative functional groups. A ring‐expanding variant (n to n+4) of the reaction provided a route to doubly benzo‐fused medium ring lactams of 10 or 11 members. Hammett analysis returned a ρ value consistent with the operation of a partially concerted reaction mechanism.
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Affiliation(s)
- Roman Abrams
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Mehul H Jesani
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Alex Browning
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Jonathan Clayden
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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Abrams R, Jesani MH, Browning A, Clayden J. Triarylmethanes and their Medium‐Ring Analogues by Unactivated Truce–Smiles Rearrangement of Benzanilides. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Roman Abrams
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Mehul H. Jesani
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Alex Browning
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Jonathan Clayden
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
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