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Kuroda Y, Krell M, Kurokawa K, Takasu K. Synthesis of mesoionic triazolones via a formal [3+2] cycloaddition between 4-phenyl-1,2,4-triazoline-3,5-dione and alkynes. Chem Commun (Camb) 2024; 60:1719-1722. [PMID: 38240015 DOI: 10.1039/d3cc05088b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
1,2,4-Triazoline-3,5-diones (TADs) are versatile reagents and have found widespread adoption in chemical science. Despite their remarkable reactivity toward a wide array of unsaturated hydrocarbons, the chemical reaction between TADs and alkynes has remained largely unexplored. Herein, we demonstrate that 1,1,1,3,3,3-hexafluoro-2-propanol facilitates the unusual [3+2] cycloaddition between 4-phenyl-1,2,4-triazoline-3,5-dione and alkynes, resulting in the formation of unprecedented mesoionic triazolones. Moreover, the structural properties of the resulting triazolone have been investigated by employing X-ray diffraction analysis and Density Functional Theory (DFT) calculations.
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Affiliation(s)
- Yusuke Kuroda
- Graduate School of Pharmaceutical Sciences, Kyoto University Yoshida, Kyoto 606-8501, Japan.
- Research Foundation ITSUU Laboratory, Kawasaki, Kanagawa 213-0012, Japan
| | - Maya Krell
- Graduate School of Pharmaceutical Sciences, Kyoto University Yoshida, Kyoto 606-8501, Japan.
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
| | - Kazuma Kurokawa
- Graduate School of Pharmaceutical Sciences, Kyoto University Yoshida, Kyoto 606-8501, Japan.
| | - Kiyosei Takasu
- Graduate School of Pharmaceutical Sciences, Kyoto University Yoshida, Kyoto 606-8501, Japan.
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2
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Nakata M, Hirashita T, Konishi Y, Araki S. Synthesis of stable class 5 mesoionic benzo[ c]tetrazolo[2,3- a]cinnolinium thiolate, dicyanomethylide, and amides. Org Biomol Chem 2023; 21:4282-4289. [PMID: 37158001 DOI: 10.1039/d3ob00362k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Although class 5 mesoionic compounds show interesting electrical behaviour, they are generally unstable, readily undergoing ring-opening reactions. We designed and synthesized a bridged mesoionic derivative, benzo[c]tetrazolo[2,3-a]cinolinium (BTC), as a stable class 5 mesoionic compound, which was further transformed to the corresponding thiolate, cicyanomethylide, and amide. The intramolecular bridging imparted stability to the BTC thiolates and amides: the BTC thiolates were unsusceptible to ring-opening at high temperatures, and the BTC amides were stable in the absence of electron-withdrawing groups on the amide nitrogen. The properties of the BTC thiolate were compared with those of 2,3-diphenyltetrazolium derivatives based on UV-Vis absorption spectroscopy, single-crystal X-ray diffraction and quantum calculations.
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Affiliation(s)
- Mirai Nakata
- Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan.
| | - Tsunehisa Hirashita
- Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan.
| | - Yoshikazu Konishi
- Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan.
| | - Shuki Araki
- Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan.
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3
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Romero-Fernández MP, Cintas P, Rojas-Buzo S. Switchable Cycloadditions of Mesoionic Dipoles: Refreshing up a Regioselective Approach to Two Distinctive Heterocycles. J Org Chem 2022; 87:12854-12866. [PMID: 36103345 PMCID: PMC9552231 DOI: 10.1021/acs.joc.2c01444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
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Mesoionic rings are
among the most versatile 1,3-dipoles, as witnessed
recently by their incorporation into bio-orthogonal strategies, and
capable of affording unconventional heterocycles beyond the expected
scope of Huisgen cycloadditions. Herein, we revisit in detail the
reactivity of thiazol-3-ium-4-olates with alkynes, leading to thiophene
and/or pyrid-2-one derivatives. A structural variation at the parent
mesoionic dipole alters sufficiently the steric outcome, thereby favoring
the regioselective formation of a single transient cycloadduct, which
undergoes chemoselective fragmentation to either five- or six-membered
heterocycles. The synthetic protocol benefits largely from microwave
(MW) activation, which enhances reaction rates. The mechanism has
been interrogated with the aid of density functional theory (DFT)
calculations, which sheds light into the origin of the regioselectivity
and points to a predictive formulation of reactivity involving competing
pathways of mesoionic cycloadditions.
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Affiliation(s)
- M. Pilar Romero-Fernández
- Department of Organic and Inorganic Chemistry, Faculty of Sciences, and IACYS-Green Chemistry and Sustainable Development Unit, University of Extremadura, 06006 Badajoz, Spain
| | - Pedro Cintas
- Department of Organic and Inorganic Chemistry, Faculty of Sciences, and IACYS-Green Chemistry and Sustainable Development Unit, University of Extremadura, 06006 Badajoz, Spain
| | - Sergio Rojas-Buzo
- Department of Organic and Inorganic Chemistry, Faculty of Sciences, and IACYS-Green Chemistry and Sustainable Development Unit, University of Extremadura, 06006 Badajoz, Spain
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4
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A theoretical study of the valence tautomerism of 1H-pyrazolium-4-olates (X = O) and related compounds (X = S, Se, NH): relative stabilities, protonation effects, and tautomerization barriers. Struct Chem 2022. [DOI: 10.1007/s11224-022-01962-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Abstract
The valence isomerism of a series of heterocyclic mesomeric betaines (HMBs) belonging to class 5, called pseudo-semi-conjugated HMBs, has been studied theoretically both the neutral and the protonated species. These HMBs are 1H-pyrazol-2-ium-4-olates and related compounds where the oxygen atom has been replaced by S, Se atoms, and an NH group. The main conclusion of the present work is that the ring/open valence tautomerism is possible both for neutral and protonated although it has never been observed experimentally.
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5
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Porte K, Riomet M, Figliola C, Audisio D, Taran F. Click and Bio-Orthogonal Reactions with Mesoionic Compounds. Chem Rev 2021; 121:6718-6743. [PMID: 33238101 DOI: 10.1021/acs.chemrev.0c00806] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Click and bio-orthogonal reactions are dominated by cycloaddition reactions in general and 1,3-dipolar cycloadditions in particular. Among the dipoles routinely used for click chemistry, azides, nitrones, isonitriles, and nitrile oxides are the most popular. This review is focused on the emerging click chemistry that uses mesoionic compounds as dipole partners. Mesoionics are a very old family of molecules, but their use as reactants for click and bio-orthogonal chemistry is quite recent. The facility to derivatize these dipoles and to tune their reactivity toward cycloaddition reactions makes mesoionics an attractive opportunity for future click chemistry development. In addition, some compounds from this family are able to undergo click-and-release reactions, finding interesting applications in cells, as well as in animals. This review covers the synthetic access to main mesoionics, their reaction with dipolarophiles, and recent applications in chemical biology and heterocycle synthesis.
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Affiliation(s)
- Karine Porte
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SCBM, 91191 Gif-sur-Yvette, France
| | - Margaux Riomet
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SCBM, 91191 Gif-sur-Yvette, France
| | - Carlotta Figliola
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SCBM, 91191 Gif-sur-Yvette, France
| | - Davide Audisio
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SCBM, 91191 Gif-sur-Yvette, France
| | - Frédéric Taran
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SCBM, 91191 Gif-sur-Yvette, France
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Nagorny S, Lederle F, Udachin V, Weingartz T, Hübner EG, Dahle S, Maus‐Friedrichs W, Adams J, Schmidt A. Switchable Mesomeric Betaines Derived from Pyridinium‐Phenolates and Bis(thienyl)ethane. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sven Nagorny
- Clausthal University of Technology Institute of Organic Chemistry Leibnizstrasse 6 38678 Clausthal-Zellerfeld Germany
| | - Felix Lederle
- Clausthal University of Technology Institute of Energy Research and Physical Technologies Am Stollen 19 B D-38640 Goslar Germany
| | - Viktor Udachin
- Clausthal University of Technology Institute of Energy Research and Physical Technologies Leibnizstrasse 4 38678 Clausthal-Zellerfeld Germany
- Clausthal University of Technology Clausthal Centre for Material Technology Agricolastrasse 2 38678 Clausthal-Zellerfeld Germany
| | - Thea Weingartz
- Clausthal University of Technology Institute of Organic Chemistry Leibnizstrasse 6 38678 Clausthal-Zellerfeld Germany
| | - Eike G. Hübner
- Clausthal University of Technology Institute of Organic Chemistry Leibnizstrasse 6 38678 Clausthal-Zellerfeld Germany
| | - Sebastian Dahle
- Clausthal University of Technology Institute of Energy Research and Physical Technologies Leibnizstrasse 4 38678 Clausthal-Zellerfeld Germany
- Clausthal University of Technology Clausthal Centre for Material Technology Agricolastrasse 2 38678 Clausthal-Zellerfeld Germany
| | - Wolfgang Maus‐Friedrichs
- Clausthal University of Technology Institute of Energy Research and Physical Technologies Leibnizstrasse 4 38678 Clausthal-Zellerfeld Germany
- Clausthal University of Technology Clausthal Centre for Material Technology Agricolastrasse 2 38678 Clausthal-Zellerfeld Germany
| | - Jörg Adams
- Clausthal University of Technology Institute of Physical Chemistry Arnold-Sommerfeld-Strasse 4 38678 Clausthal-Zellerfeld Germany
| | - Andreas Schmidt
- Clausthal University of Technology Institute of Organic Chemistry Leibnizstrasse 6 38678 Clausthal-Zellerfeld Germany
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Otto CF, Herzberger C, Liu M, Namyslo JC, Nieger M, Freese T, Lederle F, Hübner EG, Schmidt A. Borane adducts of punicine and of its dehydroxy derivatives (pyridinium-1-yl)-2- and 3-phenolates. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.131627] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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da Silva Filho AJ, da Cruz Dantas L, de Santana OL. Diradicalar Character and Ring Stability of Mesoionic Heterocyclic Oxazoles and Thiazoles by Ab Initio Mono and Multi-Reference Methods. Molecules 2020; 25:molecules25194524. [PMID: 33023193 PMCID: PMC7582729 DOI: 10.3390/molecules25194524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 11/16/2022] Open
Abstract
Mesoionics are neutral compounds that cannot be represented by a fully covalent or purely ionic structure. Among the possible mesomeric structures of these compounds are the diradical electronic configurations. Theoretical and experimental studies indicate that some mesoionic rings are unstable, which may be related to a significant diradical character, that until then is not quantified. In this work, we investigated the diradical character of four heterocycles: 1,3-oxazol-5-one, 1,3-oxazol-5-thione, 1,3-thiazole-5-one, and 1,3-thiazole-5-thione. The oxazoles are known to be significatively less stable than thiazoles. DFT and ab initio single (B3LYP, MP2, CCSD, and QCISD) and ab initio multi-reference (MR-CISD) methods with three basis sets (6-311+G(d), aug-cc-pVDZ, and aug-cc-pVTZ) were employed to assess the diradical character of the investigated systems, in gas phase and DMSO solvent, from three criteria: (i) HOMO-LUMO energy gap, (ii) determination of energy difference between singlet and triplet wave functions, and (iii) quantification of the most significant diradical character (y0, determined in the unrestricted formalism). All of the results showed that the diradical character of the investigated systems is very small. However, the calculated electronic structures made it possible to identify the possible origin of the oxazoles instability, which can help the design of mesoionic systems with the desired properties.
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Deev S, Batsyts S, Sheina E, Shestakova TS, Khalimbadzha I, Kiskin MA, Charushin V, Chupakhin O, Paramonov AS, Shenkarev ZO, Namyslo JC, Schmidt A. Betaine–N‐Heterocyclic Carbene Interconversions of Quinazolin‐4‐One Imidazolium Mesomeric Betaines. Sulfur, Selenium, and Borane Adduct Formation. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901622] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Sergey Deev
- Ural Federal University 19 Mira Street 620002 Yekaterinburg Russia
| | - Sviatoslav Batsyts
- Institute of Organic Chemistry Clausthal University of Technology Leibnizstrasse 6 38678 Clausthal‐Zellerfeld Germany
| | - Ekaterina Sheina
- Ural Federal University 19 Mira Street 620002 Yekaterinburg Russia
| | | | | | - Mikhail A. Kiskin
- N. S. Kurnakov Institute of General and Inorganic Chemistry, RAS 31 Leninsky Av. 119991 Moscow Russia
| | - Valery Charushin
- Ural Federal University 19 Mira Street 620002 Yekaterinburg Russia
- E I. Ya. Postovsky Institute of Organic Synthesis Ural Branch of the Russian Academy of Sciences 22 S. Kovalevskoy Street 620219 Yekaterinburg Russia
| | - Oleg Chupakhin
- Ural Federal University 19 Mira Street 620002 Yekaterinburg Russia
- E I. Ya. Postovsky Institute of Organic Synthesis Ural Branch of the Russian Academy of Sciences 22 S. Kovalevskoy Street 620219 Yekaterinburg Russia
| | - Alexander S. Paramonov
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences 16/10 Miklukho‐Maklaya Street 117997 Moscow Russia
| | - Zakhar O. Shenkarev
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences 16/10 Miklukho‐Maklaya Street 117997 Moscow Russia
| | - Jan C. Namyslo
- Institute of Organic Chemistry Clausthal University of Technology Leibnizstrasse 6 38678 Clausthal‐Zellerfeld Germany
| | - Andreas Schmidt
- Institute of Organic Chemistry Clausthal University of Technology Leibnizstrasse 6 38678 Clausthal‐Zellerfeld Germany
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10
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Del Bene JE, Alkorta I, Elguero J. Potential Energy Surfaces of HN(CH)SX:CO2 for X = F, Cl, NC, CN, CCH, and H: N···C Tetrel Bonds and O···S Chalcogen Bonds. J Phys Chem A 2019; 123:7270-7277. [DOI: 10.1021/acs.jpca.9b04144] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Janet E. Del Bene
- Department of Chemistry, Youngstown State University, Youngstown, Ohio 44555, United States
| | - Ibon Alkorta
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - José Elguero
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain
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11
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12
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13
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Mathieu S, Trinquier G. Oxidative addition of carbon dioxide into mesoionics. Phys Chem Chem Phys 2019; 21:5531-5565. [PMID: 30785431 DOI: 10.1039/c8cp07321j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This work examines the prospect of making stable mesoionic compounds of the type mesomeric betaine R+-CO2- from direct oxidative additions of carbon dioxide to suitably-delocalized singlet carbene moieties, with bold objectives of carbon sequestration and overall energy storage. A set of possible candidates for such mesoionic compounds is theoretically explored through DFT calculations, inspecting coupling paths, thermodynamic and kinetic stabilities, and geometric and electronic structural features. Among others, the addressed cationic parts include aromatic rings in their broader sense, phenalene systems, and odd linear polyenic chains. Various structurally-close neutral alternatives such as oxiranones or carbene-acid forms are also considered. In the linear polyenic chain family, there is stark contrast between 4N + 1 and 4N - 1 lengths, with ensuing substantial consequences for stabilities and structures. Amino substitutions can favor mesoionic arrangements through their cation-stabilizing π-donor properties, further supported by possible strong intramolecular hydrogen bonds, but they can also contribute to weaken their kinetic stability through the existence of stable neutral imino alternatives. All in all, mesoionics including tropylium, phenalene, or 4N + 1 odd polyene frames as cationic parts could be reasonable targets.
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Affiliation(s)
- Simon Mathieu
- Laboratoire de Chimie et Physique Quantiques, IRSAMC-CNRS-UMR5626, Université Paul-Sabatier (Toulouse III), 31062 Toulouse Cedex 4, France.
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14
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Zhang J, Hübner EG, Namyslo JC, Nieger M, Schmidt A. Purine-substituted imidazolium mesomeric betaines and their tautomeric N-heterocyclic carbenes. Formation of a cyclic borane adduct. Org Biomol Chem 2019; 16:6801-6808. [PMID: 30203828 DOI: 10.1039/c8ob01916a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
6-Chloropurine and 2,6-dichloropurine were reacted with N1-substituted imidazoles to give purin-6-yl substituted imidazolium salts, respectively. Deprotonation of the 1-methylimidazolium derivative resulted in the formation of the corresponding stable conjugated mesomeric betaine, whereas the 1-phenyl,- 1-vinyl- and 1-(2-hydroxyethyl) derivatives proved to be unstable. In situ generation of the mesomeric betaines by caesium carbonate in the presence of sulfur and selenium, however, gave the thiones and the selenones of the tautomeric purine-substituted imidazol-2-ylidene, respectively. Its anionic N-heterocyclic carbene was formally trapped by reaction with triethylborane at high temperatures as a cyclic boron adduct which is the first representative of a new heterocyclic ring system. DFT calculations gained insight into the electronic properties of the N-heterocyclic carbenes substituted by π-electron donators. Results of a single crystal X-ray analysis of the boron adduct are presented.
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Affiliation(s)
- Jiaxi Zhang
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany.
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15
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Schmidt A, Batsyts S, Lederle F, G. Hübner E, Adams J, C. Namyslo J. A Propeller-Shaped Mesomeric Betaine, Tetraphenylbenzene-1-Quinolinium-2-Benzoate. HETEROCYCLES 2019. [DOI: 10.3987/com-19-14160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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16
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Freese T, Namyslo JC, Nieger M, Schmidt A. Sulfur, mercury, and boron adducts of sydnone imine derived anionic N-heterocyclic carbenes. RSC Adv 2019; 9:4781-4788. [PMID: 35514659 PMCID: PMC9060589 DOI: 10.1039/c9ra00294d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 01/31/2019] [Indexed: 01/30/2023] Open
Abstract
The sydnone imines (5-benzoylimino)-3-(2-methoxyphenyl)-sydnone imine and molsidomine were deprotonated at C4 to give sydnone imine anions which can be represented as anionic N-heterocyclic carbenes, respectively. Trapping reactions with sulfur gave unstable sydnone imine sulfides which were stabilized by the formation of methyl thioethers, methyl sulfoxides, gold complexes [(PPh3)Au–S-sydnone imine] and a bis(ligand) mercury(ii) complex. The latter possesses a tetrahedral coordination of the mercury central atom to the sulfur atoms with the N6 nitrogen atoms coordinating as neutral ligands. Water converted the molsidomine anion into ethyl(2-morpholino-2-thioxoacetyl)carbamate. Mercury(ii)chloride and triphenylborane were employed to trap the sydnone imine carbenes as mercury complexes as well as BPh3 adducts. The sydnone imines (5-benzoylimino)-3-(2-methoxyphenyl)-sydnone imine and molsidomine were deprotonated at C4 to give sydnone imine anions which can be represented as anionic N-heterocyclic carbenes, respectively.![]()
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Affiliation(s)
- Tyll Freese
- Clausthal University of Technology
- Institute of Organic Chemistry
- Germany
| | - Jan C. Namyslo
- Clausthal University of Technology
- Institute of Organic Chemistry
- Germany
| | - Martin Nieger
- Department of Chemistry
- University of Helsinki
- Finland
| | - Andreas Schmidt
- Clausthal University of Technology
- Institute of Organic Chemistry
- Germany
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de la Concepción JG, Ávalos M, Cintas P, Jiménez JL. Computational Screening of New Orthogonal Metal-Free Dipolar Cycloadditions of Mesomeric Betaines. Chemistry 2018. [PMID: 29534312 DOI: 10.1002/chem.201800869] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Computational strategies have gained increasing impact in the de novo design of large molecular sets targeted to a desired application. Herein, DFT-assisted theoretical analyses of cycloadditions, involving mesoionic dipoles and strained cycloalkynes, unveil a series of unexplored mesomeric betaines as vastly superior candidates for orthogonal applications. Thus, isosydnones; thiosydnones; and a six-membered homolog, 6-oxo-1,3-oxazinium-4-olate, exhibit enhanced reactivity with respect to sydnone, which is the archetypal mesoionic ring employed so far in orthogonal chemistry. These compounds were found by assessing energy barriers and transition structures, which are largely governed by electron fluxes from dipolarophile to dipole and noncovalent interactions. Charge-transfer analysis also accounts for previous experimental and theoretical results gathered in the literature, and provides a rationale for further substitution variations. The above naked dipoles release only CO2 as a byproduct through retro-Diels-Alder of the resulting cycloadducts. These results should invite practitioners to look at such underestimated dipoles and could also help to minimize the number of experiments.
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Affiliation(s)
- Juan García de la Concepción
- Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias, Universidad de Extremadura, Avenida de Elvas S/N, Badajoz, 06006, Spain
| | - Martín Ávalos
- Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias, Universidad de Extremadura, Avenida de Elvas S/N, Badajoz, 06006, Spain
| | - Pedro Cintas
- Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias, Universidad de Extremadura, Avenida de Elvas S/N, Badajoz, 06006, Spain
| | - José Luis Jiménez
- Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias, Universidad de Extremadura, Avenida de Elvas S/N, Badajoz, 06006, Spain
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18
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Lücke AL, Wiechmann S, Freese T, Nieger M, Földes T, Pápai I, Gjikaj M, Adam A, Schmidt A. Anionic N-heterocyclic carbenes by decarboxylation of sydnone-4-carboxylates. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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19
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Champagne PA, Houk KN. Influence of Endo- and Exocyclic Heteroatoms on Stabilities and 1,3-Dipolar Cycloaddition Reactivities of Mesoionic Azomethine Ylides and Imines. J Org Chem 2017; 82:10980-10988. [PMID: 28876936 DOI: 10.1021/acs.joc.7b01928] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The geometries, stabilities, and 1,3-dipolar cycloaddition reactivities of 24 mesoionic azomethine ylides and imines were investigated using density functional theory calculations at the M06-2X/6-311+G-(d,p)/M06-2X/6-31G-(d) level. The computed structures highlight how the commonly used "aromatic" resonance form should be replaced by two more accurate resonance structures. Stabilities of the dipoles were assessed by various homodesmotic schemes and are consistent with these compounds being nonaromatic. The activation free energies with ethylene or acetylene range from 11.8 to 36.6 kcal/mol. Within each dipole type, the predicted cycloaddition reactivities correlate with the reaction energies and the resonance stabilization energies provided by the various substituents. Endocyclic (X) heteroatoms increase the reactivity of the 1,3-dipoles in the order of O > NH ≅ S, whereas exocyclic (Y) substituents increase it in the order of CH2 > NH > O > S. Distortion/interaction analysis indicated that the difference in reactivity between differently substituted 1,3-dipoles is driven by distortion, whereas the difference between azomethine ylides and imines is related to lower interaction energies of imines with the dipolarophiles.
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Affiliation(s)
- Pier Alexandre Champagne
- Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States
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The intersection of allenylidenes and mesomeric betaines. 1-Methylpyridinium-2-acetylide and its palladium complexes. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Schmidt A, Batsyts S, Smeyanov A, Freese T, Hübner EG, Nieger M. Dipolar Bent and Linear Acetylenes Substituted by Cationic Quinolinium and Anionic Benzoates. Formation of Mesomeric Betaines. J Org Chem 2016; 81:4202-9. [DOI: 10.1021/acs.joc.6b00561] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andreas Schmidt
- Clausthal University of Technology, Institute of Organic
Chemistry, Leibnizstrasse
6, D-38678 Clausthal-Zellerfeld, Germany
| | - Sviatoslav Batsyts
- Clausthal University of Technology, Institute of Organic
Chemistry, Leibnizstrasse
6, D-38678 Clausthal-Zellerfeld, Germany
| | - Alexey Smeyanov
- Clausthal University of Technology, Institute of Organic
Chemistry, Leibnizstrasse
6, D-38678 Clausthal-Zellerfeld, Germany
| | - Tyll Freese
- Clausthal University of Technology, Institute of Organic
Chemistry, Leibnizstrasse
6, D-38678 Clausthal-Zellerfeld, Germany
| | - Eike G. Hübner
- Clausthal University of Technology, Institute of Organic
Chemistry, Leibnizstrasse
6, D-38678 Clausthal-Zellerfeld, Germany
| | - Martin Nieger
- University of Helsinki, Department of Chemistry, Laboratory
of Inorganic Chemistry, P.O. Box 55, FIN-00014 University of Helsinki, Finland
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Lücke AL, Wiechmann S, Freese T, Guan Z, Schmidt A. Palladium complexes of anionic N-heterocyclic carbenes derived from sydnones in catalysis. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2016. [DOI: 10.1515/znb-2016-0006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The anion of N-phenylsydnone, which can be generated on treatment of N-phenylsydnone with cyanomethyllithium without decomposition, can be represented as tripolar zwitterionic and as anionic N-heterocyclic carbene resonance forms. Its palladium complex was prepared from 4-bromo-3-phenylsydnone and tetrakis(triphenylphosphine)palladium and proved to be active as catalyst in Suzuki-Miyaura reactions. Thus, 2,5-dibromo-3,4-dinitrothiophene was effectively converted into 2,5-diaryl-3,4-dinitrothiophenes with 1-naphthyl, (4-trifluoromethoxy)phenyl, [4-(methylsulfanyl)phenyl], and biphenyl-4-yl boronic acid. 3-(Phenanthren-9-yl)quinoline was prepared by Suzuki-Miyaura reaction starting from 3-bromoquinoline. 1-Chloro-2,4-dinitrobenzene cross-coupled with phenyl boronic acid, 1-naphthyl boronic acid, 9-phenanthryl boronic acid. 4-Bromobenzylic alcohol gave (4-isopropylphenyl)methanol on sydnone-palladium complex-catalyzed reaction with isopropyl boronic acid.
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Affiliation(s)
- Ana-Luiza Lücke
- Institute of Organic Chemistry , Clausthal University of Technology , Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany
| | - Sascha Wiechmann
- Institute of Organic Chemistry , Clausthal University of Technology , Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany
| | - Tyll Freese
- Institute of Organic Chemistry , Clausthal University of Technology , Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany
| | - Zong Guan
- Institute of Organic Chemistry , Clausthal University of Technology , Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany
| | - Andreas Schmidt
- Institute of Organic Chemistry , Clausthal University of Technology , Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany
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Liu M, Nieger M, Hübner EG, Schmidt A. Formation of N-Heterocyclic Carbenes by Tautomerization of Mesomeric Betaines: Cyclic Boron Adducts and Palladium Complexes From 2-(Imidazolium-1-yl)phenolates. Chemistry 2016; 22:5416-24. [PMID: 26929134 DOI: 10.1002/chem.201505042] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Indexed: 11/09/2022]
Abstract
2-(Imidazolium-1-yl)phenolates are conjugated heterocyclic mesomeric betaines in tautomeric equilibrium with the corresponding N-heterocyclic carbenes (NHCs), 3-(2-hydroxyphenyl)-imidazol-2-ylidenes. The carbene tautomers can be trapped as thiones (X-ray analysis). Moreover, bis(triphenylphosphine)palladium(II) dichloride in THF trapped the carbene tautomer as a palladium complex without participation of the phenolate group (X-ray analysis). The corresponding anionic NHCs, 2-phenolate-substituted imidazol-2-ylidenes, can be trapped by triethylborane or triphenylborane to form 4,4-diethyl- or 4,4-diphenyl-4H-benzo[e]imidazo[2,1-c][1,4,2]oxaza-borininium-4-ides, respectively (two X-ray analyses). These tricyclic systems are the first representatives of a new heterocyclic ring system. The results of DFT calculations concerning the HOMO/LUMO profiles and partial charges are also presented.
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Affiliation(s)
- Ming Liu
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678, Clausthal-Zellerfeld, Germany), Fax: (+49)-5323-722834
| | - Martin Nieger
- University of Helsinki, Laboratory of Inorganic Chemistry, Department of Chemistry, P.O. Box 55 (A.I. Virtasen aukio 1), 00014, Helsinki, Finland
| | - Eike G Hübner
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678, Clausthal-Zellerfeld, Germany), Fax: (+49)-5323-722834
| | - Andreas Schmidt
- Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, 38678, Clausthal-Zellerfeld, Germany), Fax: (+49)-5323-722834.
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