1
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Ebert M, Lange A, Müller M, Wuckert E, Gießelmann F, Klamroth T, Zens A, Taubert A, Laschat S. Counterion effects on the mesomorphic and electrochemical properties of guanidinium salts. Phys Chem Chem Phys 2024; 26:11988-12002. [PMID: 38573315 DOI: 10.1039/d4cp00356j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Ionic liquid crystals (ILCs) combine the ion mobility of ionic liquids with the order and self-assembly of thermotropic mesophases. To understand the role of the anion in ILCs, wedge-shaped arylguanidinium salts with tetradecyloxy side chains were chosen as benchmark systems and their liquid crystalline self-assembly in the bulk phase as well as their electrochemical behavior in solution were studied depending on the anion. Differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (WAXS, SAXS) experiments revealed that for spherical anions, the phase width of the hexagonal columnar mesophase increased with the anion size, while for non-spherical anions, the trends were less clear cut. Depending on the anion, the ILCs showed different stability towards electrochemical oxidation and reduction with the most stable being the PF6 based compound. Cyclic voltammetry (CV) and density functional theory (DFT) calculations suggest a possible contribution of the guanidinium cation to the oxidation processes.
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Affiliation(s)
- Max Ebert
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany.
| | - Alyna Lange
- Institut für Chemie, Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Str. 24-25, Golm 14476, Germany.
| | - Michael Müller
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany.
| | - Eugen Wuckert
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany.
| | - Frank Gießelmann
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany.
| | - Tillmann Klamroth
- Institut für Chemie, Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Str. 24-25, Golm 14476, Germany.
| | - Anna Zens
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany.
| | - Andreas Taubert
- Institut für Chemie, Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Str. 24-25, Golm 14476, Germany.
| | - Sabine Laschat
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany.
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2
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Lee H, Nam H, Lee SY. Enantio- and Diastereoselective Variations on α-Iminonitriles: Harnessing Chiral Cyclopropenimine-Thiourea Organocatalysts. J Am Chem Soc 2024; 146:3065-3074. [PMID: 38281151 DOI: 10.1021/jacs.3c09911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
Chiral 1-pyrrolines containing a nitrile motif serve as crucial structural scaffolds in biologically active molecules and exhibit diversity as building blocks owing to their valuable functional groups; however, the asymmetric synthesis of such compounds remains largely unexplored. Herein, we present an enantio- and diastereoselective method for the synthesis of α-chiral nitrile-containing 1-pyrroline derivatives bearing vicinal stereocenters through the design and introduction of chiral cyclopropenimine-based bifunctional catalysts featuring a thiourea moiety. This synthesis entails a highly stereoselective conjugate addition of α-iminonitriles to a wide array of enones, followed by cyclocondensation, thereby affording a series of cyanopyrroline derivatives, some of which contain all-carbon quaternary centers. Moreover, we demonstrate the synthetic utility of this strategy by performing a gram-scale reaction with 1% catalyst loading, along with a variety of chemoselective transformations of the product, including the synthesis of a vildagliptin analogue. Finally, we showcase the selective synthesis of all four stereoisomers of the cyanopyrroline products through trans-to-cis isomerization, highlighting the versatility of our approach.
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Affiliation(s)
- Hooseung Lee
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Hyeongwoo Nam
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Sarah Yunmi Lee
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
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3
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Ratto A, Honek JF. Oxocarbon Acids and their Derivatives in Biological and Medicinal Chemistry. Curr Med Chem 2024; 31:1172-1213. [PMID: 36915986 DOI: 10.2174/0929867330666230313141452] [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: 09/29/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 03/15/2023]
Abstract
The biological and medicinal chemistry of the oxocarbon acids 2,3- dihydroxycycloprop-2-en-1-one (deltic acid), 3,4-dihydroxycyclobut-3-ene-1,2-dione (squaric acid), 4,5-dihydroxy-4-cyclopentene-1,2,3-trione (croconic acid), 5,6-dihydroxycyclohex- 5-ene-1,2,3,4-tetrone (rhodizonic acid) and their derivatives is reviewed and their key chemical properties and reactions are discussed. Applications of these compounds as potential bioisosteres in biological and medicinal chemistry are examined. Reviewed areas include cell imaging, bioconjugation reactions, antiviral, antibacterial, anticancer, enzyme inhibition, and receptor pharmacology.
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Affiliation(s)
- Amanda Ratto
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| | - John F Honek
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
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4
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Choi S, Choi Y, Kim Y, Lee J, Lee SY. Copper-Catalyzed C-C Cross-Couplings of Tertiary Alkyl Halides with Anilines Enabled by Cyclopropenimine-Based Ligands. J Am Chem Soc 2023. [PMID: 37933129 DOI: 10.1021/jacs.3c09369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Catalytic cross-couplings of tertiary alkyl electrophiles with carbon nucleophiles offer a powerful platform for constructing quaternary carbon centers, which are prevalent in bioactive molecules. However, these reactions remain underdeveloped primarily because of steric challenges that impede efficient bond formation. Herein, we describe the copper-catalyzed synthesis of such centers through the C(sp3)-C(sp2) bond-forming reaction between tertiary alkyl halides and arene rings of aniline derivatives, enabled by the strategic implementation of bidentate bis(cyclopropenimine) ligands. The copper catalyst bound by two imino-nitrogen atoms of these ligands, which have never been employed in metal catalysis previously, is highly effective in rapidly activating tertiary halides to generate alkyl radicals, allowing them to react with aryl nucleophiles under mild conditions with remarkably short reaction times (1-2 h). Various tertiary halides bearing carbonyl functional groups can be coupled with secondary or primary anilines, furnishing a range of quaternary carbon centers in good yields. Several mechanistic observations support the generation of copper(II) species and alkyl radicals which as a result elucidate the steps in the proposed catalytic cycle.
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Affiliation(s)
- Serim Choi
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Yongseok Choi
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Yongjae Kim
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Jaehoo Lee
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Sarah Yunmi Lee
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
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5
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Mishiro K, Ueno T, Wakabayashi H, Fukui M, Kinuya S, Ogawa K. Synthesis and evaluation of a deltic guanidinium analogue of a cyclic RGD peptide. Org Biomol Chem 2023; 21:1937-1941. [PMID: 36752554 DOI: 10.1039/d3ob00089c] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A guanidine group is abundantly found in natural products and drugs. Guanidine has the highest basicity among many common functional groups in nature. Because of its high basicity, it generally exists as a protonated guanidinium and functions as a cationic hydrogen bond donor. Finding an appropriate bioisostere of guanidinium is challenging because of its high basicity and unique trigonal planar shape. In this study, we explored the possibility of "deltic guanidinium" as a bioisostere of guanidinium using a cyclic arginine-glycine-aspartic acid (RGD) peptide as a parent compound. We synthesized c(deltic RGDyK), in which a guanidinium group of an arginine residue in c(RGDyK) is replaced with deltic guanidinium. A target binding assay, biodistribution study, and metabolic stability assay were conducted with c(deltic RGDyK) and its radioiodinated variant. The deltic guanidinium analog peptides exhibited similar biological properties to the parent peptides and improved in vivo stability, indicating that deltic guanidinium could work as a unique bioisostere of guanidinium.
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Affiliation(s)
- Kenji Mishiro
- Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.
| | - Takahiro Ueno
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Hiroshi Wakabayashi
- Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan
| | - Masato Fukui
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Seigo Kinuya
- Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan
| | - Kazuma Ogawa
- Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan. .,Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
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6
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Abstract
Cyclopropenium ions are the smallest class of aromatic compounds, satisfying Hückel's rules of aromaticity with two π electrons within a three-membered ring. First prepared by Breslow in 1957, cyclopropenium ions have been found to possess extraordinary stability despite being both cationic and highly strained. In the 65 years since their first preparation, cyclopropenium ions have been the subject of innumerable studies concerning their synthesis, physical properties, and reactivity. However, prior to our work, the reactivity of these unique carbocations had not been exploited for reaction promotion or catalysis.Over the past 13 years, we have been exploring aromatic ions as unique and versatile building blocks for the development of catalysts for organic chemistry. A major portion of this work has been focused on leveraging the remarkable properties of the smallest of the aromatic ions─cyclopropeniums─as a design element in the invention of highly reactive catalysts. Indeed, because of its unique profile of hydrolytic stability, compact geometry, and relatively easy oxidizability, the cyclopropenium ring has proven to be a highly advantageous construction module for catalyst invention.In this Account, we describe some of our work using cyclopropenium ions as a key element in the design of novel catalysts. First, we discuss our early work aimed at promoting dehydrative reactions, starting with Appel-type chlorodehydrations of alcohols and carboxylic acids, cyclic ether formations, and Beckmann rearrangements and culminating in the realization of catalytic chlorodehydrations of alcohols and a catalytic Mitsunobu-type reaction. Next, we describe the development of cyclopropenimines as strong, neutral organic Brønsted bases and, in particular, the use of chiral cyclopropenimines for enantioselective Brønsted catalysis. We also describe the development of higher-order cyclopropenimine superbases. The use of tris(amino)cyclopropenium (TAC) ions as a novel class of phase-transfer catalysts is discussed for the reaction of epoxides with carbon dioxide. Next, we describe the formation of a cyclopropenone radical cation that has a portion of its spin density on the oxygen atom, leading to some peculiar metal ligand behavior. Finally, we discuss recent work that employs TAC electrophotocatalysts for oxidation reactions. The key intermediate for this chemistry is a TAC radical dication, which as an open-shell photocatalyst has remarkably strong excited-state oxidizing power. We describe the application of this strategy to transformations ranging from the oxidative functionalization of unactivated arenes to the regioselective derivatization of ethers, C-H aminations, vicinal C-H diaminations, and finally aryl olefin dioxygenations. Collectively, these catalytic platforms demonstrate the utility of charged aromatic rings, and cyclopropenium ions in particular, to enable unique advances in catalysis.
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Affiliation(s)
- Rebecca M Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Tristan H Lambert
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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7
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Muñoz Sánchez GM, Zdilla MJ. Crystal structure of N-butyl-2,3-bis-(di-cyclo-hexyl-amino)-cyclo-propeniminium chloride benzene monosolvate. Acta Crystallogr E Crystallogr Commun 2022; 78:936-941. [PMID: 36072514 PMCID: PMC9443799 DOI: 10.1107/s2056989022008076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 08/11/2022] [Indexed: 11/16/2022]
Abstract
N-Butyl-2,3-bis-(di-cyclo-hexyl-amino)-cyclo-propenimine (1) crystallizes from benzene and hexa-nes in the presence of HCl as a mono-benzene solvate of the hydro-chloride salt, [1H]Cl·C6H6 or C31H54N3 +·Cl-·C6H6, in the P21/n space group. The protonation of 1 results in the generation of an aromatic structure based upon the delocalization of the cyclo-propene double bond around the cyclo-propene ring, giving three inter-mediate C-C bond lengths of ∼1.41 Å, and the delocalization of the imine-type C-N double bond, giving three inter-mediate C-N bond lengths of ∼1.32 Å. Ion-ion and ion-benzene packing inter-actions are described and illustrated.
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Affiliation(s)
- Gaby M. Muñoz Sánchez
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, PA 19122, USA
| | - Michael J. Zdilla
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, PA 19122, USA
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8
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Holmes ST, Hook JM, Schurko RW. Nutraceuticals in Bulk and Dosage Forms: Analysis by 35Cl and 14N Solid-State NMR and DFT Calculations. Mol Pharm 2021; 19:440-455. [PMID: 34792373 DOI: 10.1021/acs.molpharmaceut.1c00708] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study uses 35Cl and 14N solid-state NMR (SSNMR) spectroscopy and dispersion-corrected plane-wave density functional theory (DFT) calculations for the structural characterization of chloride salts of nutraceuticals in their bulk and dosage forms. For eight nutraceuticals, we measure the 35Cl EFG tensor parameters of the chloride ions and use plane-wave DFT calculations to elucidate relationships between NMR parameters and molecular-level structure, which provide rapid NMR crystallographic assessments of structural features. We employ both 35Cl direct excitation and 1H→35Cl cross-polarization methods to characterize a dosage form containing α-d-glucosamine HCl, observe possible impurity and/or adulterant phases, and quantify the weight percent of the active ingredient. To complement this, we also investigate 14N SSNMR spectroscopy and DFT calculations to characterize nitrogen atoms in the nutraceuticals. This includes a discussion of targeted acquisition experimental protocols (i.e., acquiring a select region of the overall pattern that features key discontinuities) that allow ultrawideline spectra to be acquired rapidly, even for unreceptive samples (i.e., those with long values of T1(14N), short values of T2eff(14N), or very broad patterns). It is hoped that these experimental and computational protocols will be useful for the characterization of various solid forms of nutraceuticals (i.e., salts, polymorphs, hydrates, solvates, cocrystals, amorphous solid dispersions, etc.), help detect impurity and counterfeit solid phases in dosage forms, and serve as a foundation for future NMR crystallographic studies of nutraceutical solid forms, including studies using ab initio crystal structure prediction algorithms.
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Affiliation(s)
- Sean T Holmes
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.,National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - James M Hook
- NMR Facility, Mark Wainwright Analytical Centre, The University of New South Wales, Sydney, New South Wales 2052, Australia.,School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Robert W Schurko
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.,National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
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9
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Agnew-Francis KA, Williams CM. Squaramides as Bioisosteres in Contemporary Drug Design. Chem Rev 2020; 120:11616-11650. [DOI: 10.1021/acs.chemrev.0c00416] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Kylie A. Agnew-Francis
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Craig M. Williams
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
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10
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Litterscheidt J, Bandar JS, Ebert M, Forschner R, Bader K, Lambert TH, Frey W, Bühlmeyer A, Brändle M, Schulz F, Laschat S. Self-Assembly of Aminocyclopropenium Salts: En Route to Deltic Ionic Liquid Crystals. Angew Chem Int Ed Engl 2020; 59:10557-10565. [PMID: 32119178 PMCID: PMC7317216 DOI: 10.1002/anie.202000824] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/25/2020] [Indexed: 01/27/2023]
Abstract
Aminocyclopropenium ions have raised much attention as organocatalysts and redox active polymers. However, the self-assembly of amphiphilic aminocyclopropenium ions remains challenging. The first deltic ionic liquid crystals based on aminocyclopropenium ions have been developed. Differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction provided insight into the unique self-assembly and nanosegregation of these liquid crystals. While the combination of small headgroups with linear p-alkoxyphenyl units led to bilayer-type smectic mesophases, wedge-shaped units resulted in columnar mesophases. Upon increasing the size and polyphilicity of the aminocyclopropenium headgroup, a lamellar phase was formed.
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Affiliation(s)
- Juri Litterscheidt
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Jeffrey S. Bandar
- Department of ChemistryColorado State UniversityFort CollinsCO80523USA
| | - Max Ebert
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Robert Forschner
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Korinna Bader
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Tristan H. Lambert
- Department of Chemistry & Chemical BiologyCornell University122 Baker LaboratoryIttacaNY14853USA
- Department of ChemistryColumbia UniversityNew YorkNY10027USA
| | - Wolfgang Frey
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Andrea Bühlmeyer
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Marcus Brändle
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Finn Schulz
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Sabine Laschat
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
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11
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Litterscheidt J, Bandar JS, Ebert M, Forschner R, Bader K, Lambert TH, Frey W, Bühlmeyer A, Brändle M, Schulz F, Laschat S. Self‐Assembly of Aminocyclopropenium Salts: En Route to Deltic Ionic Liquid Crystals. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Juri Litterscheidt
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Jeffrey S. Bandar
- Department of Chemistry Colorado State University Fort Collins CO 80523 USA
| | - Max Ebert
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Robert Forschner
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Korinna Bader
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Tristan H. Lambert
- Department of Chemistry & Chemical Biology Cornell University 122 Baker Laboratory Ittaca NY 14853 USA
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Wolfgang Frey
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Andrea Bühlmeyer
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Marcus Brändle
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Finn Schulz
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Sabine Laschat
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
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12
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Strater ZM, Rauch M, Jockusch S, Lambert TH. Oxidizable Ketones: Persistent Radical Cations from the Single‐Electron Oxidation of 2,3‐Diaminocyclopropenones. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Zack M. Strater
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Michael Rauch
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Steffen Jockusch
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Tristan H. Lambert
- Department of Chemistry Columbia University New York NY 10027 USA
- Department of Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
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13
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Strater ZM, Rauch M, Jockusch S, Lambert TH. Oxidizable Ketones: Persistent Radical Cations from the Single-Electron Oxidation of 2,3-Diaminocyclopropenones. Angew Chem Int Ed Engl 2019; 58:8049-8052. [PMID: 30964215 DOI: 10.1002/anie.201902265] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/29/2019] [Indexed: 11/07/2022]
Abstract
Single electron oxidation of 2,3-diaminocyclopropenones is shown to give rise to stable diaminocyclopropenium oxyl (DACO) radical cations. Cyclic voltammetry reveals reversible oxidations in the range of +0.70-1.10 V (vs. SCE). Computational, EPR, and X-ray analysis support the view that the oxidized species is best described as a cyclopropenium ion with spin density located on the heteroatom substituents, including 23.5 % on oxygen. The metal-ligand behavior of the DACO radical is also described.
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Affiliation(s)
- Zack M Strater
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Michael Rauch
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Steffen Jockusch
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Tristan H Lambert
- Department of Chemistry, Columbia University, New York, NY, 10027, USA.,Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
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14
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The Construction and Application of C=S Bonds. Top Curr Chem (Cham) 2018; 376:31. [DOI: 10.1007/s41061-018-0209-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/24/2018] [Indexed: 01/30/2023]
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15
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Zwicker VE, Yuen KKY, Smith DG, Ho J, Qin L, Turner P, Jolliffe KA. Deltamides and Croconamides: Expanding the Range of Dual H‐bond Donors for Selective Anion Recognition. Chemistry 2017; 24:1140-1150. [DOI: 10.1002/chem.201704388] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - David G. Smith
- School of Chemistry The University of Sydney NSW 2006 Australia
| | - Junming Ho
- School of Chemistry University of New South Wales NSW 2052 Australia
| | - Lei Qin
- School of Chemistry The University of Sydney NSW 2006 Australia
| | - Peter Turner
- School of Chemistry The University of Sydney NSW 2006 Australia
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16
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Curnow OJ, Yunis R. Synthesis, characterization and properties of amino acid ionic liquids derived from the triaminocyclopropenium cation. RSC Adv 2016. [DOI: 10.1039/c6ra10171b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Amino acid ionic liquids based on the triaminocyclopropenium cation form a variety of structural types depending on the amino acid. Dications were obtained with Lys, His, Arg, and Cys.
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Affiliation(s)
- Owen J. Curnow
- Department of Chemistry
- University of Canterbury
- Christchurch 8140
- New Zealand
| | - Ruhamah Yunis
- Department of Chemistry
- University of Canterbury
- Christchurch 8140
- New Zealand
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