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Yisimayili N, Li ZF, Liu T, Lu CD. Stereoselective Electrophilic Sulfenylation of β,β-Disubstituted Enesulfinamides: Asymmetric Construction of Less Accessible Acyclic α,α-Disubstituted α-Sulfenylated Ketimines. Org Lett 2024. [PMID: 38967298 DOI: 10.1021/acs.orglett.4c02030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
Current methods for the asymmetric α-sulfenylation of carbonyls cannot be applied to acyclic carbonyls that have two similar substituents at the α-position. This research demonstrated that the electrophilic sulfenylation of geometry-defined acyclic β,β-disubstituted enesulfinamides using S-aryl or S-alkyl benzenethiosulfonates can be highly stereoselective. This process results in enantioenriched α,α-disubstituted α-sulfenylated ketone surrogates with sulfur-containing acyclic tetrasubstituted carbon stereocenters bearing two electronically and sterically similar substituents (e.g., methyl and ethyl). Furthermore, by employing the corresponding stereoisomers of enensulfinamides, any of the four stereoisomers of α-sulfenylated ketimines can be selectively accessed.
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Affiliation(s)
| | - Zheng-Fei Li
- School of Chemical Science and Technology, Yunnan University, Kunming, Yunnan 650091, China
| | - Tao Liu
- School of Chemical Science and Technology, Yunnan University, Kunming, Yunnan 650091, China
| | - Chong-Dao Lu
- School of Chemical Science and Technology, Yunnan University, Kunming, Yunnan 650091, China
- School of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
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2
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Kojima Y, Nishii Y, Hirano K. Asymmetric Synthesis of SCF 3-Substituted Alkylboronates by Copper-Catalyzed Hydroboration of 1-Trifluoromethylthioalkenes. Angew Chem Int Ed Engl 2024; 63:e202403337. [PMID: 38472112 DOI: 10.1002/anie.202403337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 03/14/2024]
Abstract
A synthetic method for preparation of optically active trifluoromethylthio (SCF3) compounds by a copper-catalyzed regio- and enantioselective hydroboration of 1-trifluoromethylthioalkenes with H-Bpin has been developed. The enantioselective hydrocupration of an in situ generated CuH species and subsequent boration reaction generate a chiral SCF3-containing alkylboronate, of which Bpin moiety can be further transformed to deliver various optically active SCF3 molecules. Computational studies suggest that the SCF3 group successfully controls the regioselectivity in the reaction.
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Affiliation(s)
- Yuki Kojima
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yuji Nishii
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Koji Hirano
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka, 565-0871, Japan
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3
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Pan B, Li A, Liu D, Ni Q, Liang W, Du F, Gu J, Ouyang Q. Highly diastereoselective synthesis of benzothiazolo[3,2- a]pyridines via [4 + 2] annulation reaction of 2-vinylbenzothiazoles and azlactones. Org Biomol Chem 2022; 20:4512-4517. [PMID: 35593711 DOI: 10.1039/d2ob00618a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient AgOTf-catalyzed [4 + 2] annulation reaction of 2-vinylbenzothiazoles and azlactones was successfully performed under mild reaction conditions. With this approach, a series of novel benzothiazolo[3,2-a]pyridine derivatives was readily obtained in good to excellent yields (68-96%), with high diastereoselectivities and tolerating quite a broad scope of substituents. By using chiral phosphoric acid catalyst, the desired products were obtained in high enantioselectivities, up to -94%. This methodology provides a rapid and useful method for constructing fused benzothiazole derivatives.
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Affiliation(s)
- Bin Pan
- College of Pharmacy, Third Military Medical University, Shapingba, Chongqing 400038, China.
| | - Ao Li
- College of Pharmacy, Third Military Medical University, Shapingba, Chongqing 400038, China.
| | - Dong Liu
- College of Pharmacy, Third Military Medical University, Shapingba, Chongqing 400038, China.
| | - QingShan Ni
- Biomedical Analysis Center, School of Basic Medical Science, Third Military Medical University, Chongqing, 400038, China
| | - Wu Liang
- College of Pharmacy, Chongqing Medical University, Chongqing 400016, China
| | - Fei Du
- College of Pharmacy, Chongqing Medical University, Chongqing 400016, China
| | - Jing Gu
- College of Pharmacy, Third Military Medical University, Shapingba, Chongqing 400038, China.
| | - Qin Ouyang
- College of Pharmacy, Third Military Medical University, Shapingba, Chongqing 400038, China.
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Santos IA, de Castro PP, dos Santos HF, Amarante GW. Mechanism and Origin of Enantioselectivity in Bifunctional Squaramide‐Catalyzed α‐Thiolation of Azlactones. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | | | | | - Giovanni Wilson Amarante
- Federal University of Juiz de Fora Department of Chemistry Louren�o Kelmer, s/nS�o Pedro 36036-900 Juiz de Fora BRAZIL
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Niedbała P, Majdecki M, Grodek P, Jurczak J. H-Bond Mediated Phase-Transfer Catalysis: Enantioselective Generating of Quaternary Stereogenic Centers in β-Keto Esters. Molecules 2022; 27:molecules27082508. [PMID: 35458707 PMCID: PMC9024675 DOI: 10.3390/molecules27082508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 02/01/2023] Open
Abstract
In this work, we would like to present the development of a highly optimized method for generating the quaternary stereogenic centers in β-keto esters. This enantioselective phase-transfer alkylation catalyzed by hybrid Cinchona catalysts allows for the efficient generation of the optically active products with excellent enantioselectivity, using only 1 mol% of the catalyst. The vast majority of phase-transfer catalysts in asymmetric synthesis work by creating ionic pairs with the nucleophile-attacking anionic substrate. Therefore, it is a sensible approach to search for new methodologies capable of introducing functional groups into the precursor’s structure, maintaining high yields and enantiomeric purity.
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Ghosh P, Rozenberg I, Maayan G. Sequence-function relationship within water-soluble Peptoid Chelators for Cu 2. J Inorg Biochem 2021; 217:111388. [PMID: 33618230 DOI: 10.1016/j.jinorgbio.2021.111388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/31/2021] [Accepted: 02/05/2021] [Indexed: 12/26/2022]
Abstract
Chelation of Cu2+ by synthetic molecules is an emerging therapeutic approach for treating several illnesses in human body such as Wilson disease, cancer and more. Among synthetic metal chelators, those based on peptoids - N-substituted glycine oligomers - are advantageous due to their structural similarity to peptides, ease of synthesis on solid support and versatile controlled sequences. Tuning peptoid sequences, via systematically changing at least one side chain, can facilitate and control their function. Along these lines, this work aims to explore the role of the non-coordinating side chain within peptoid chelators in order to understand the factors that control the selectivity of these chelators to Cu2+ in water medium. To this aim, a set of peptoid trimers having a pyridine group at the acetylated N-terminal, a 2,2'-bipyridine group at the second position and a non-coordinating group at the C-terminus, where the latter is systematically varied between aromatic, aliphatic, chiral or non-chiral, were investigated as selective chelators for Cu2+. The effect of the position of the non-coordinating group on the selectivity of the peptoid to Cu2+ was also tested. Based on extensive spectroscopic data, we found that the choice of the non-coordinating group along with its position dramatically influences the selectivity of the peptoids to Cu2+. We showed that peptoids having bulky chiral groups at the C-terminus enable high selectivity to Cu2+. We further demonstrated the ability of one of the selective chelators to remove Cu2+ from the natural copper binding protein metallothionein in HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) buffer medium.
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Affiliation(s)
- Pritam Ghosh
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel
| | - Ido Rozenberg
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel
| | - Galia Maayan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel.
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Stereoselective Synthesis of Chiral α-SCF3-β-Ketoesters Featuring a Quaternary Stereocenter. Symmetry (Basel) 2021. [DOI: 10.3390/sym13010092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The development of new and efficient methods, reagents, and catalysts for the introduction of fluorine atoms or fluorinated moieties in molecular scaffolds has become a topic of paramount importance in organic synthesis. In this framework, the incorporation of the SCF3 group into organic molecule has often led to beneficial effects on the drug’s metabolic stability and bioavailability. Here we report our studies aimed to the stereoselective synthesis of chiral α-SCF3-β−ketoesters featuring a tetrasubstituted stereocenter. The use of a chiral auxiliary was crucial to synthesize enantiopure enamines that were reacted with N-trifluoromethylthio saccharin or phthalimide, to afford enantioenriched α-SCF3-tetrasubstitued β-keto esters. By using a readily available, inexpensive chiral diamine, such as trans-1,2-diaminocyclohexane, the fluorinated products could be obtained in modest to good yields, and, after the removal of the chiral auxiliary, α-substituted- α trifluoromethylthio-β−ketoesters were isolated with high enantioselectivity (up to 91% ee).
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Eder I, Haider V, Zebrowski P, Waser M. Recent Progress in the Asymmetric Syntheses of α‐Heterofunctionalized (Masked) α‐ and β‐Amino Acid Derivatives. European J Org Chem 2020. [DOI: 10.1002/ejoc.202001077] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Isabella Eder
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
| | - Victoria Haider
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
| | - Paul Zebrowski
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
| | - Mario Waser
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
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