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Bourgeois F, Höller U, Netscher T. Synthesis of trifold-labeled versatile reagent [3,5- 13 C 2 ,4- 15 N]4-phenyl-1,2,4-triazoline-3,5-dione. J Labelled Comp Radiopharm 2023; 66:461-466. [PMID: 37985145 DOI: 10.1002/jlcr.4067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 11/22/2023]
Abstract
Triazolinediones are an important class of derivatization agents that have found application in various research disciplines. Their unique reactivity often allows precise and selective tagging of relevant molecular scaffolds to facilitate structural elucidation, tracking in biological systems, and stabilization of labile compounds. Recent research efforts mainly focused on the development of novel fluorescent and ionizable or isotopically labeled tags improving the quantification and identification of the parent molecule by suitable analytical methods. However, these concepts often lack the ability to improve properties facilitating the analysis by nuclear magnetic resonance (NMR) spectroscopy. We herein describe the first synthesis of 13 C and 15 N labeled [3,5-13 C2 ,4-15 N]4-phenyl-1,2,4-triazoline-3,5-dione utilizing the Cookson/Zinner-Deucker synthesis of urazoles. The introduced isotopic labels are ideally suited to support the structural elucidation of unknown and complex derivatization mixtures by NMR, thereby exploiting the increased sensitivity of detecting long-range JHC and additional JCC and JCN couplings within the derivatized compounds of interest.
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Affiliation(s)
| | - Ulrich Höller
- dsm-firmenich, Science and Research, Basel, Switzerland
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2
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Bevernaege K, Tzouras NV, Poater A, Cavallo L, Nolan SP, Nahra F, Winne JM. Site selective gold(i)-catalysed benzylic C-H amination via an intermolecular hydride transfer to triazolinediones. Chem Sci 2023; 14:9787-9794. [PMID: 37736629 PMCID: PMC10510626 DOI: 10.1039/d3sc03683a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 08/22/2023] [Indexed: 09/23/2023] Open
Abstract
Triazolinediones are known as highly reactive dienophiles that can also act as electrophilic amination reagents towards enolisable C-H bonds (ionic pathway) or weak C-H bonds (free radical pathway). Here, we report that this C-H amination reactivity can be significantly extended and enhanced via gold(i)-catalysis. Under mild conditions, several alkyl-substituted aryls successfully undergo benzylic C-H aminations at room temperature. The remarkable site selectivity that is observed points towards strong electronic activation and deactivation effects, that go beyond a simple weakening of the C-H bond. The observed catalytic C-H aminations do not follow the expected trends for a free radical-type C-H amination and show complementarity to existing methods. Density functional theory (DFT) calculations and distinct experimental trends provide a clear mechanistic rationale for observed selectivity patterns, postulating a novel pathway for triazolinedione-induced aminations via a carbon-to-nitrogen hydride transfer.
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Affiliation(s)
- Kevin Bevernaege
- Department of Organic and Macromolecular Chemistry, Ghent University Krijgslaan 281-S4 B-9000 Ghent Belgium
| | - Nikolaos V Tzouras
- Department of Chemistry and Center for Sustainable Chemistry, Ghent University Krijgslaan 281-S3 B-9000 Ghent Belgium
| | - Albert Poater
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Girona C/Maria Aurèlia Capmany 69 17003 Girona Spain
| | - Luigi Cavallo
- KAUST Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology Thuwal 23955 Saudi Arabia
| | - Steven P Nolan
- Separation and Conversion Technology, VITO (Flemish Institute for Technological Research) Boeretang 200 2400 Mol Belgium
| | - Fady Nahra
- Department of Chemistry and Center for Sustainable Chemistry, Ghent University Krijgslaan 281-S3 B-9000 Ghent Belgium
- Separation and Conversion Technology, VITO (Flemish Institute for Technological Research) Boeretang 200 2400 Mol Belgium
| | - Johan M Winne
- Department of Organic and Macromolecular Chemistry, Ghent University Krijgslaan 281-S4 B-9000 Ghent Belgium
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3
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Martin KL, Breton GW. Computational, 1H NMR, and X-ray structural studies on 1-arylurazole tetrazane dimers. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2017; 73:660-666. [PMID: 28872061 DOI: 10.1107/s2053229617010786] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 07/21/2017] [Indexed: 11/10/2022]
Abstract
Nitrogen-centered urazole radicals exist in equilibrium with tetrazane dimers in solution. The equilibrium established typically favors the free-radical form. However, 1-arylurazole radicals bearing substituents at the ortho position favor the dimeric form. We were able to determine the structure of one of the dimers (substituted at both ortho positions with methyl groups), namely 1,2-(2,4-dimethylphenyl)-2-[2-(2,4-dimethylphenyl)-4-methyl-3,5-dioxo-1,2,4-triazolidin-1-yl]-4-methyl-1,2,4-triazolidine-3,5-dione, C24H28N6O4, via X-ray crystallography. The experimentally determined structure agreed well with the computationally obtained geometry at the B3LYP/6-311G(d,p) level of theory. The preferred syn conformation of these 1-arylurazole dimers results in the two aromatic rings being proximate and nearly parallel, which leads to some interesting shielding effects of certain signals in the 1H NMR spectrum. Armed with this information, we were able to decipher the more complicated 1H NMR spectrum obtained from a dimer that was monosubstituted at the ortho position with a methyl group.
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Affiliation(s)
- Kenneth L Martin
- Department of Chemistry and Biochemistry, Berry College, Mount Berr, GA, USA
| | - Gary W Breton
- Department of Chemistry and Biochemistry, Berry College, Mount Berr, GA, USA
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De Bruycker K, Billiet S, Houck HA, Chattopadhyay S, Winne JM, Du Prez FE. Triazolinediones as Highly Enabling Synthetic Tools. Chem Rev 2016; 116:3919-74. [DOI: 10.1021/acs.chemrev.5b00599] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevin De Bruycker
- Department of Organic and
Macromolecular Chemistry, Polymer Chemistry Research Group and Laboratory
for Organic Synthesis, Ghent University, Krijgslaan 281 S4, B-9000 Ghent, Belgium
| | - Stijn Billiet
- Department of Organic and
Macromolecular Chemistry, Polymer Chemistry Research Group and Laboratory
for Organic Synthesis, Ghent University, Krijgslaan 281 S4, B-9000 Ghent, Belgium
| | - Hannes A. Houck
- Department of Organic and
Macromolecular Chemistry, Polymer Chemistry Research Group and Laboratory
for Organic Synthesis, Ghent University, Krijgslaan 281 S4, B-9000 Ghent, Belgium
| | - Subrata Chattopadhyay
- Department of Organic and
Macromolecular Chemistry, Polymer Chemistry Research Group and Laboratory
for Organic Synthesis, Ghent University, Krijgslaan 281 S4, B-9000 Ghent, Belgium
| | - Johan M. Winne
- Department of Organic and
Macromolecular Chemistry, Polymer Chemistry Research Group and Laboratory
for Organic Synthesis, Ghent University, Krijgslaan 281 S4, B-9000 Ghent, Belgium
| | - Filip E. Du Prez
- Department of Organic and
Macromolecular Chemistry, Polymer Chemistry Research Group and Laboratory
for Organic Synthesis, Ghent University, Krijgslaan 281 S4, B-9000 Ghent, Belgium
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5
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Breton GW, Suroviec AH. Intermediacy of a Persistent Urazole Radical and an Electrophilic Diazenium Species in the Acid-Catalyzed Reaction of MeTAD with Anisole. J Org Chem 2016; 81:206-14. [PMID: 26649733 DOI: 10.1021/acs.joc.5b02520] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of N-methyl-1,2,4-triazoline-3,5-dione (MeTAD) with anisole in the presence of trifluoroacetic acid affords unexpected disubstituted urazole products instead of the expected monosubstituted urazole as typically observed in the reactions of MeTAD with other substituted benzenes. Our investigation into the mechanism of formation of these disubstituted products suggests that MeTAD is capable of further reaction with the initially formed monosubstituted urazole to afford a persistent urazole radical. The identity of this radical has been established by UV-vis spectroscopy, the nature of its self-dimerization reaction, and via independent generation. Electrochemical oxidation of this radical was carried out, and the resulting diazenium ion was demonstrated to be reactive with added substituted benzenes, including anisole. When oxidation was carried out chemically using thianthrenium perchlorate in the presence of anisole it was shown to produce the same disubstituted products (and in the same ratio) as observed in the acid-catalyzed reaction. A common diazenium species is proposed to be active in both cases. We also report the synthesis and characterization of three interesting tetrazane dimers resulting from unstable urazole radicals.
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Affiliation(s)
- Gary W Breton
- Department of Chemistry, Berry College , Mount Berry, Georgia 30149, United States
| | - Alice H Suroviec
- Department of Chemistry, Berry College , Mount Berry, Georgia 30149, United States
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Alternative synthetic routes to N-methyl-1,2,4-triazoline-3,5-dione (MeTAD) and other triazolinedione derivatives. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.06.091] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Zhirov AM, Aksenov AV. Azodicarboxylates: synthesis and functionalization of organic compounds. RUSSIAN CHEMICAL REVIEWS 2014. [DOI: 10.1070/rc2014v083n06abeh004419] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Breton GW, Hoke KR. Application of radical cation spin density maps toward the prediction of photochemical reactivity between N-methyl-1,2,4-triazoline-3,5-dione and substituted benzenes. J Org Chem 2013; 78:4697-707. [PMID: 23594077 DOI: 10.1021/jo4001417] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Visible light irradiation of N-methyl-1,2,4-triazoline-3,5-dione in the presence of substituted benzenes is capable of inducing substitution reactions where no reaction takes place thermally. In addition to the formation of 1-arylurazole products resulting from ring substitution, side-chain substitution occurs in some cases where benzylic hydrogens are accessible to form benzylic urazole products. Formation of both types of products is most consistent with the involvement of a common intermediate, a radical ion pair, generated from photoexcitation of an initially formed charge-transfer complex. The charge-transfer complexes have been observed spectroscopically. Additionally, application of a modified Rehm-Weller model suggests that the electron-transfer processes are feasible for all of the substrates examined. In most cases, the spin density maps of the aromatic radical cation intermediates calculated at the DFT UB3LYP/6-31G* level are excellent predictors of the observed product distributions.
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Affiliation(s)
- Gary W Breton
- Department of Chemistry, Berry College, 2277 Martha Berry Highway, Mount Berry, Georgia 30149, USA.
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Michaels HA, Simmons JT, Clark RJ, Zhu L. Fused Polycyclic Compounds via Cycloaddition of 4-(1′-Cyclohexenyl)-5-iodo-1,2,3-triazoles with 4-Phenyl-1,2,4-triazoline-3,5-dione: The Importance of a Sacrificial Iodide Leaving Group. J Org Chem 2013; 78:5038-44. [DOI: 10.1021/jo400271j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Heather A. Michaels
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee,
Florida 32306-4390, United States
| | - J. Tyler Simmons
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee,
Florida 32306-4390, United States
| | - Ronald J. Clark
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee,
Florida 32306-4390, United States
| | - Lei Zhu
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee,
Florida 32306-4390, United States
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