1
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Lopes Jesus AJ, Nunes CM, Ferreira GA, Keyvan K, Fausto R. Photochemical Generation and Characterization of C-Aminophenyl-Nitrilimines: Insights on Their Bond-Shift Isomers by Matrix-Isolation IR Spectroscopy and Density Functional Theory Calculations. Molecules 2024; 29:3497. [PMID: 39124902 PMCID: PMC11314218 DOI: 10.3390/molecules29153497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Revised: 07/20/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024] Open
Abstract
The intriguing ability of C-phenyl-nitrilimine to co-exist as allenic and propargylic bond-shift isomers motivated us to investigate how substituents in the phenyl ring influence this behavior. Building on our previous work on the meta- and para-OH substitution, here we extended this investigation to explore the effect of the NH2 substitution. For this purpose, C-(4-aminophenyl)- and C-(3-aminophenyl)-nitrilimines were photogenerated in an argon matrix at 15 K by narrowband UV-light irradiation (λ = 230 nm) of 5-(4-aminophenyl)- and 5-(3-aminophenyl)-tetrazole, respectively. The produced nitrilimines were further photoisomerized to carbodiimides via 1H-diazirines by irradiations at longer wavelengths (λ = 380 or 330 nm). Combining IR spectroscopic measurements and DFT calculations, it was found that the para-NH2-substituted nitrilimine exists as a single isomeric structure with a predominant allenic character. In contrast, the meta-NH2-substituted nitrilimine co-exists as two bond-shift isomers characterized by propargylic and allenic structures. To gain further understanding of the effects of phenyl substitution on the bond-shift isomerism of the nitrilimine fragment, we compared geometric and charge distribution data derived from theoretical calculations performed for C-phenyl-nitrilimine with those performed for the derivatives resulting from NH2 (electron-donating group) and NO2 (electron-withdrawing group) phenyl substitutions.
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Affiliation(s)
- A. J. Lopes Jesus
- University of Coimbra, CQC-IMS, Faculty of Pharmacy, 3004-295 Coimbra, Portugal
| | - Cláudio M. Nunes
- University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, Portugal; (C.M.N.); (G.A.F.); (K.K.); (R.F.)
| | - Gil A. Ferreira
- University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, Portugal; (C.M.N.); (G.A.F.); (K.K.); (R.F.)
| | - Kiarash Keyvan
- University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, Portugal; (C.M.N.); (G.A.F.); (K.K.); (R.F.)
| | - R. Fausto
- University of Coimbra, CQC-IMS, Department of Chemistry, 3004-535 Coimbra, Portugal; (C.M.N.); (G.A.F.); (K.K.); (R.F.)
- Istanbul Kultur University, Faculty Sciences and Letters, Department of Physics, Bakirkoy, 34158 Istanbul, Turkey
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2
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Yang Y, Liang J, Li W, Yang W, Wang C, Zhang X, Fang WH, Guo Z, Chen X. Mechanistic Understanding and Reactivity Analyses for the Photochemistry of Disubstituted Tetrazoles. J Phys Chem A 2023; 127:4115-4124. [PMID: 37133205 DOI: 10.1021/acs.jpca.3c01594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The photolysis of tetrazoles has undergone extensive research. However, there are still some problems to be solved in terms of mechanistic understanding and reactivity analyses, which leaves room for theoretical calculations. Herein, multiconfiguration perturbation theory at the CASPT2//CASSCF level was employed to account for electron correction effects involved in the photolysis of four disubstituted tetrazoles. Based on calculations of vertical excitation properties and evaluations of intersystem crossing (ISC) efficiencies in the Frank-Condon region, the combination of space and electronic effects is found in maximum-absorption excitation. Two types of ISC (1ππ* → 3nπ*, 1ππ* → 3ππ*) are determined in disubstituted tetrazoles, and the obtained rates follow the El-Sayed rule. Through mapping three representative types of minimum energy profiles for the photolysis of 1,5-, and 2,5-disubstituted tetrazoles, a conclusion can be drawn that the photolysis of tetrazoles exhibits reactivity characteristic of bond-breaking selectivity. Kinetic evaluations show that the photogeneration of singlet imidoylnitrene operates predominately over that in the triplet state, which can be confirmed by a double-well model in the triplet potential energy surface of 1,5-disubstituted tetrazole. Similar mechanistic explorations and reactivity analyses were also applied to the photolysis of 2,5-disubstituted tetrazole to unveil fragmentation patterns of nitrile imine generation. All computational efforts allow us to better understand the photoreactions of disubstituted tetrazoles and to provide useful strategies for regulating their unique reactivity.
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Affiliation(s)
- Yanting Yang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Jing Liang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Weijia Li
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Wenjing Yang
- College of Materials Science & Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, People's Republic of China
| | - Chu Wang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Xiaorui Zhang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Zhen Guo
- College of Materials Science & Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, People's Republic of China
| | - Xuebo Chen
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
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3
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Zhang Y, Zeng JL, Chen Z, Wang R. Base-Promoted (3 + 2) Cycloaddition of Trifluoroacetohydrazonoyl Chlorides with Imidates En Route to Trifluoromethyl-1,2,4-Triazoles. J Org Chem 2022; 87:14514-14522. [PMID: 36264227 DOI: 10.1021/acs.joc.2c01926] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A base-mediated (3 + 2) cycloaddition of trifluoroacetohydrazonoyl chlorides with imidates for the construction of 3-trifluoromethyl-1,2,4-triazoles has been described. This reaction is characterized by readily starting materials, simple reaction conditions, good yields, a broad substrate scope, and excellent regioselectivity. The utility of this protocol has been validated by the synthesis of a drug-like molecule.
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Affiliation(s)
- Yue Zhang
- Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, the Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China
| | - Jun-Liang Zeng
- School of Chemistry and Chemical Engineering, Xuchang University, Henan 461000, China
| | - Zhen Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Ren Wang
- Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, the Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China
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4
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Characterization of hitherto unknown Valsartan photodegradation impurities. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.134599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Flesch S, Vöhringer P. Ultrafast Dynamics of Photochemical Nitrile Imine Formation. Angew Chem Int Ed Engl 2022; 61:e202205803. [PMID: 35583254 PMCID: PMC9400991 DOI: 10.1002/anie.202205803] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Indexed: 12/05/2022]
Abstract
The chemical reactivity of nitrile imines is of great utility in organic synthesis with applications rapidly expanding into the materials and life sciences. Yet, our understanding of the electronic and molecular structures of nitrile imines remains incomplete and the elementary mechanism of their photoinduced generation is entirely unknown. Here, femtosecond infrared spectroscopy after 266 nm‐excitation of 2,5‐diphenyltetrazole has been carried out to temporally resolve the formation and structural relaxation dynamics of the nascent diphenylnitrile imine in liquid solution under ambient conditions. The infrared‐spectroscopic evolution is interpreted by an initial sequence of intersystem crossings within 250 fs followed by the cleavage of N2 with formation of a structurally relaxed nitrile imine on the adiabatic ground‐state singlet surface within a few tens of picoseconds. The infrared spectrum supports the notion of a “floppy” nitrile imine molecule whose equilibrium character ranges from fully propargylic to fully allenic in the room temperature liquid solution.
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Affiliation(s)
- Stefan Flesch
- Clausius-Institut für Physikalische und Theoretische Chemie Rheinische Friedrich-Wilhelms-Universität Wegelerstraße 12 53115 Bonn Germany
| | - Peter Vöhringer
- Clausius-Institut für Physikalische und Theoretische Chemie Rheinische Friedrich-Wilhelms-Universität Wegelerstraße 12 53115 Bonn Germany
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6
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Flesch S, Vöhringer P. Ultrafast Dynamics of Photochemical Nitrile Imine Formation. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205803] [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)
- Stefan Flesch
- Clausius-Institut für Physikalische und Theoretische Chemie Rheinische Friedrich-Wilhelms-Universität Wegelerstraße 12 53115 Bonn Germany
| | - Peter Vöhringer
- Clausius-Institut für Physikalische und Theoretische Chemie Rheinische Friedrich-Wilhelms-Universität Wegelerstraße 12 53115 Bonn Germany
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7
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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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8
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Yavari I, Fadakar Y. Reverse orientation in the ultrasound-assisted [3 + 2]-cycloaddition reaction of nitrile imines with 3-formylchromone-Meldrum's acid adducts. Mol Divers 2021; 26:1141-1150. [PMID: 34129183 DOI: 10.1007/s11030-021-10240-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/28/2021] [Indexed: 11/26/2022]
Abstract
The [3 + 2]-cycloaddition reaction of nitrile imines with 2,2-dimethyl-5-[(4-oxo-4H-chromen-3-yl)methylene]-1,3-dioxane-4,6-dione tends to form the reverse-orientation products under ultrasound irradiation in EtOH in the presence of Et3N. Evidence for the structure of product 5b was obtained from single-crystal X-ray analysis.
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Affiliation(s)
- Issa Yavari
- Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
| | - Younes Fadakar
- Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran
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9
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Marshall DL, Menzel JP, McKinnon BI, Blinco JP, Trevitt AJ, Barner-Kowollik C, Blanksby SJ. Laser Photodissociation Action Spectroscopy for the Wavelength-Dependent Evaluation of Photoligation Reactions. Anal Chem 2021; 93:8091-8098. [PMID: 34019383 DOI: 10.1021/acs.analchem.1c01584] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nitrile imine-mediated tetrazole-ene cycloaddition is a widely used class of photoligation. Optimizing the reaction outcome requires detailed knowledge of the tetrazole photoactivation profile, which can only partially be ascertained from absorption spectroscopy, or otherwise involves laborious reaction monitoring in solution. Photodissociation action spectroscopy (PDAS) combines the advantages of optical spectroscopy and mass spectrometry in that only absorption events resulting in a mass change are recorded, thus revealing the desired wavelength dependence of product formation. Moreover, the sensitivity and selectivity afforded by the mass spectrometer enable reliable assessment of the photodissociation profile even on small amounts of crude material, thus accelerating the design and synthesis of next-generation substrates. Using this workflow, we demonstrate that the photodissociation onset for nitrile imine formation is red-shifted by ca. 50 nm with a novel N-ethylcarbazole derivative relative to a phenyl-substituted archetype. Benchmarked against solution-phase tunable laser experiments and supported by quantum chemical calculations, these discoveries demonstrate that PDAS is a powerful tool for rapidly screening the efficacy of new substrates in the quest toward efficient visible light-triggered ligation for biological applications.
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Affiliation(s)
- David L Marshall
- Central Analytical Research Facility, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Jan P Menzel
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Benjamin I McKinnon
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - James P Blinco
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Adam J Trevitt
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Christopher Barner-Kowollik
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Stephen J Blanksby
- Central Analytical Research Facility, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
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10
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Tian Y, Li J, Zhang F, Ma J. Regioselective Decarboxylative Cycloaddition Route to Fully Substituted 3‐CF
3
‐Pyrazoles from Nitrilimines and Isoxazolidinediones. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100091] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yu‐Chen Tian
- Department of Chemistry Tianjin Key Laboratory of Molecular Optoelectronic Sciences Frontiers Science Center for Synthetic Biology (Ministry of Education) and Tianjin Collaborative Innovation Centre of Chemical Science & Engineering Tianjin University Tianjin 300072
| | - Jun‐Kuan Li
- Department of Chemistry Tianjin Key Laboratory of Molecular Optoelectronic Sciences Frontiers Science Center for Synthetic Biology (Ministry of Education) and Tianjin Collaborative Innovation Centre of Chemical Science & Engineering Tianjin University Tianjin 300072
| | - Fa‐Guang Zhang
- Department of Chemistry Tianjin Key Laboratory of Molecular Optoelectronic Sciences Frontiers Science Center for Synthetic Biology (Ministry of Education) and Tianjin Collaborative Innovation Centre of Chemical Science & Engineering Tianjin University Tianjin 300072
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University, Binhai New City Fuzhou 350207 People's Republic of China
| | - Jun‐An Ma
- Department of Chemistry Tianjin Key Laboratory of Molecular Optoelectronic Sciences Frontiers Science Center for Synthetic Biology (Ministry of Education) and Tianjin Collaborative Innovation Centre of Chemical Science & Engineering Tianjin University Tianjin 300072
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University, Binhai New City Fuzhou 350207 People's Republic of China
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11
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Ildiz GO, Fausto R. Conformational Analysis, Spectroscopy and Photochemistry of Matrix-Isolated 1H- and 2H- Tautomeric Forms of Ethyl Tetrazole-5- Carboxylate. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2020.112899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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12
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Marchais J, Bégué D, Dargelos A, Wentrup C. Rearrangements of Aromatic Nitrile Oxides and Nitrile Ylides: Potential Ring Expansion to Cycloheptatetraene Derivatives Mimicking Arylcarbenes. Chemistry 2020; 26:15700-15707. [DOI: 10.1002/chem.202003782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/09/2020] [Indexed: 11/06/2022]
Affiliation(s)
- Jérémy Marchais
- CNRS/Université de Pau et des Pays de l'Adour/E2S UPPA Institut des Sciences Analytiques et, de Physicochimie pour l'Environnement et les Matériaux, UMR5254 64000 Pau France
| | - Didier Bégué
- CNRS/Université de Pau et des Pays de l'Adour/E2S UPPA Institut des Sciences Analytiques et, de Physicochimie pour l'Environnement et les Matériaux, UMR5254 64000 Pau France
| | - Alain Dargelos
- CNRS/Université de Pau et des Pays de l'Adour/E2S UPPA Institut des Sciences Analytiques et, de Physicochimie pour l'Environnement et les Matériaux, UMR5254 64000 Pau France
| | - Curt Wentrup
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane Queensland 4072 Australia
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13
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Bégué D, Dargelos A, Wentrup C. Aryl Nitrile Imines and Diazo Compounds. Formation of Indazole, Pyridine N-Imine, and 2-Pyridyldiazomethane from Tetrazoles. J Org Chem 2020; 85:7952-7958. [DOI: 10.1021/acs.joc.0c00773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Didier Bégué
- CNRS/Université de Pau et des Pays de l’Adour/E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l’Environnement et les Matériaux, UMR5254, Pau 64000, France
| | - Alain Dargelos
- CNRS/Université de Pau et des Pays de l’Adour/E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l’Environnement et les Matériaux, UMR5254, Pau 64000, France
| | - Curt Wentrup
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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14
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Zhao X, Liu Q, Feng R, Zeng X, Wentrup C. Photolysis and Pyrolysis of Phenyltetrazoles: Formation of Phenylcarbodiimide, N-
Phenylnitrile Imine, Phenylnitrene, Indazole, and Fulvenallene. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901271] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Xiaofang Zhao
- College of Chemistry; Chemical Engineering and Materials Science; Soochow University; 215123 Suzhou P. R. China
| | - Qian Liu
- College of Chemistry; Chemical Engineering and Materials Science; Soochow University; 215123 Suzhou P. R. China
| | - Ruijuan Feng
- College of Chemistry; Chemical Engineering and Materials Science; Soochow University; 215123 Suzhou P. R. China
| | - Xiaoqing Zeng
- College of Chemistry; Chemical Engineering and Materials Science; Soochow University; 215123 Suzhou P. R. China
| | - Curt Wentrup
- School of Chemistry and Molecular Biosciences; Chemical Engineering and Materials Science; The University of Queensland; 4072 Brisbane Queensland Australia
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15
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Bégué D, Dargelos A, Wentrup C. Rearrangements of Nitrile Imines: Ring Expansion of Benzonitrile Imines to Cycloheptatetraenes and Ring Closure to 3-Phenyl-3 H-diazirines. J Org Chem 2019; 84:8668-8673. [PMID: 31244156 DOI: 10.1021/acs.joc.9b01183] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nitrile imines are important intermediates in 1,3-dipolar cycloaddition reactions, and they are also known to undergo efficient, unimolecular rearrangements to carbodiimides via 1 H-diazirines and imidoylnitrenes under both thermal and photochemical reaction conditions. We now report a competing rearrangement, revealed by CASPT2(14,12) and B3LYP calculations, in which C-phenylnitrile imines 8 undergo ring expansion to 1-diazenyl-1,2,4,6-cycloheptatetraenes 12 akin to the phenylcarbene-cycloheptatetraene rearrangement. Amino-, hydroxy-, and thiol-groups in the meta positions of C-phenylnitrile imine lower the activation energies for this rearrangement so that it becomes potentially competitive with the cyclization to 1 H-diazirines and hence rearrange to carbodiimides. The diazenylcycloheptatetraenes 12 thus formed can evolve further to cycloheptatetraene 30 and 2-diazenyl-phenylcarbene 16 over modest activation barriers, and the latter carbenes cyclize very easily to 2 H- and 3 H-indazoles, from which 6-methylenecyclohexadienylidene, phenylcarbene, fulvenallene, and their isomers are potentially obtainable. Moreover, another new rearrangement of benzonitrile imine forms 3-phenyl-3 H-diazirine, which is a precursor of phenyldiazomethane and hence phenylcarbene. This reaction is competitive with the ring expansion. The new rearrangements predicted here should be experimentally observable, for example, under matrix photolysis or flash vacuum pyrolysis conditions.
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Affiliation(s)
- Didier Bégué
- CNRS/Université de Pau et des Pays de l'Adour/E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, UMR5254 , Pau 64000 , France
| | - Alain Dargelos
- CNRS/Université de Pau et des Pays de l'Adour/E2S UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, UMR5254 , Pau 64000 , France
| | - Curt Wentrup
- School of Chemistry and Molecular Biosciences , The University of Queensland , Brisbane , Queensland 4072 , Australia
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16
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Bégué D, Dargelos A, Braybrook C, Wentrup C. Phenylnitrene Radical Cation and Its Isomers from Tetrazoles, Nitrile Imines, Indazole, and Benzimidazole. J Phys Chem A 2019; 123:1410-1422. [PMID: 30689388 DOI: 10.1021/acs.jpca.8b11858] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Phenylnitrene radical cations m/ z 91, C6H5N, 8a•+ are observed in the mass spectra of 1-, 2-, and 5-phenyltetrazoles, even though no C-N bond is present in 5-phenyltetrazole. Calculations at the B3LYP/6-311G(d,p) level of theory indicate that initial formation of the C-phenylimidoylnitrene 13•+ and/or benzonitrile imine radical cation 19•+ from 1 H- and 2 H-5-phenyltetrazoles 11 and 12 is followed by isomerizations of 13•+ to the phenylcyanamide ion 15•+ over a low barrier. A cyclization of imidoylnitrene ion 13•+ onto the benzene ring offers alternate, very facile routes to the phenylnitrene ion 8a•+ and the phenylcarbodiimide ion 14•+ via the azabicyclooctadienimine 16•+. Eliminations of HNC or HCN from 14•+ and 15•+ again yield the phenylnitrene radical cation 8a•+. A direct 1,3-H shift isomerizing phenylcarbodiimide ion 14•+ to the phenylcyanamide ion 15•+ requires a very high activation energy of 114 kcal/mol, and this reaction needs not be involved. The benzonitrile imine -3-phenyl-1 H-diazirine-phenylimidoylnitrene-phenylcarbodiimide/phenylcyanamide rearrangement has parallels in thermal and photochemical processes, but the facile cyclization of imidoylnitrene 13•+ to azabicyclooctadienimine 16•+ is facilitated by the positive charge making the nitrene more electrophilic. Furthermore, the benzonitrile imine radical cation 19•+ can cyclize to indazole 24•+, and a series of intramolecular rearrangements via hydrogen shifts, ring-openings and ring closures allow the interconversion of numerous ions of composition C7H6N2•+, including 19•+, 24•+, the benzimidazole ion 38•+ and o-aminobenzonitrile ion 40•+, all of which can eliminate either HCN or HNC to yield the C6H5N•+ ions of phenylnitrene, 8a•+, and/or iminocyclohexadienylidene, 34•+. Moreover, benzonitrile imine 19•+ can behave like a benzylic carbenium ion, undergoing a novel ring expansion to cycloheptatetraenyldiazene 45•+. The N-phenylnitrile imine ion 2d•+ derived from 2-phenyltetrazole 1d cleaves efficiently to the phenylnitrene ion 8a•+ but may also cyclize to the indazole ion 24•+. The N-phenylimidoylnitrene 59•+ derived from 1-phenyltetrazole 5d undergoes facile isomerization to the phenylcyanamide ion 15•+ and hence phenylnitrene radical cation 8a•+.
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Affiliation(s)
- Didier Bégué
- Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, UMR5254 , CNRS/Université de Pau et des Pays de l'Adour/E2S UPPA , 64000 , Pau , France
| | - Alain Dargelos
- Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, UMR5254 , CNRS/Université de Pau et des Pays de l'Adour/E2S UPPA , 64000 , Pau , France
| | - Carl Braybrook
- Ian Wark Laboratory , CSIRO , Clayton , Victoria 3169 , Australia
| | - Curt Wentrup
- School of Chemistry and Molecular Biosciences , The University of Queensland , Brisbane , Queensland 4072 , Australia
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Nunes CM, Pinto SM, Reva I, Rosado MT, Fausto R. Photochemistry of matrix-isolated 3-chloro-1,2-benzisoxazole: Generation and characterization of 2-cyanophenoxyl radical and other reactive intermediates. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2017.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Wentrup C. Carbenes and Nitrenes: Recent Developments in Fundamental Chemistry. Angew Chem Int Ed Engl 2018; 57:11508-11521. [DOI: 10.1002/anie.201804863] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Curt Wentrup
- School of Chemistry and Molecular BiosciencesThe University of Queensland Brisbane Qld 4072 Australia
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19
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Abe M, Bégué D, Silva HS, Dargelos A, Wentrup C. Triplet States of Tetrazoles, Nitrenes, and Carbenes from Matrix Photolysis of Tetrazoles, and Phenylcyanamide as a Source of Phenylnitrene. J Phys Chem A 2018; 122:7276-7283. [DOI: 10.1021/acs.jpca.8b06960] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Manabu Abe
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Didier Bégué
- Institut des Sciences Analytiques et de Physicochimie pour l’Environnement et les Matériaux, CNRS/Université de Pau et des Pays de l’Adour/E2S UPPA, UMR5254, Pau 64000, France
| | - Hugo Santos Silva
- Institut des Sciences Analytiques et de Physicochimie pour l’Environnement et les Matériaux, CNRS/Université de Pau et des Pays de l’Adour/E2S UPPA, UMR5254, Pau 64000, France
| | - Alain Dargelos
- Institut des Sciences Analytiques et de Physicochimie pour l’Environnement et les Matériaux, CNRS/Université de Pau et des Pays de l’Adour/E2S UPPA, UMR5254, Pau 64000, France
| | - Curt Wentrup
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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20
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Wentrup C. Carbene und Nitrene: Aktuelle Entwicklungen in der Grundlagenchemie. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804863] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Curt Wentrup
- School of Chemistry and Molecular Biosciences; The University of Queensland; Brisbane Qld 4072 Australien
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21
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Nunes CM, Reva I, Kozuch S, McMahon RJ, Fausto R. Photochemistry of 2-Formylphenylnitrene: A Doorway to Heavy-Atom Tunneling of a Benzazirine to a Cyclic Ketenimine. J Am Chem Soc 2017; 139:17649-17659. [DOI: 10.1021/jacs.7b10495] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Cláudio M. Nunes
- CQC, Department
of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Igor Reva
- CQC, Department
of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Sebastian Kozuch
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 841051, Israel
| | - Robert J. McMahon
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706-1322, United States
| | - Rui Fausto
- CQC, Department
of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
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22
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Affiliation(s)
- Curt Wentrup
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane Qld 4072 Australien
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23
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Wentrup C. Flash Vacuum Pyrolysis: Techniques and Reactions. Angew Chem Int Ed Engl 2017; 56:14808-14835. [PMID: 28675675 DOI: 10.1002/anie.201705118] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Indexed: 12/13/2022]
Abstract
Flash vacuum pyrolysis (FVP) had its beginnings in the 1940s and 1950s, mainly through mass spectrometric detection of pyrolytically formed free radicals. In the 1960s many organic chemists started performing FVP experiments with the purpose of isolating new and interesting compounds and understanding pyrolysis processes. Meanwhile, many different types of apparatus and techniques have been developed, and it is the purpose of this review to present the most important methods as well as a survey of typical reactions and observations that can be achieved with the various techniques. This includes preparative FVP, chemical trapping reactions, matrix isolation, and low temperature spectroscopy of reactive intermediates and unstable molecules, the use of online mass, photoelectron, microwave, and millimeterwave spectroscopies, gas-phase laser pyrolysis, pulsed pyrolysis with supersonic jet expansion, very low pressure pyrolysis for kinetic investigations, solution-spray and falling-solid FVP for involatile compounds, and pyrolysis over solid supports and reagents. Moreover, the combination of FVP with matrix isolation and photochemistry is a powerful tool for investigations of reaction mechanism.
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Affiliation(s)
- Curt Wentrup
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld, 4072, Australia
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24
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Bégué D, Santos-Silva H, Dargelos A, Wentrup C. Imidoylnitrenes R′C(═NR)–N, Nitrile Imines, 1H-Diazirines, and Carbodiimides: Interconversions and Rearrangements, Structures, and Energies at DFT and CASPT2 Levels of Theory. J Phys Chem A 2017; 121:8227-8235. [DOI: 10.1021/acs.jpca.7b08445] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Didier Bégué
- Institut
Pluridisciplinaire de Recherche sur l’Environnement et les
Matériaux, Université de Pau et des Pays de l’Adour, 64000 Pau, France
| | - Hugo Santos-Silva
- Institut
Pluridisciplinaire de Recherche sur l’Environnement et les
Matériaux, Université de Pau et des Pays de l’Adour, 64000 Pau, France
| | - Alain Dargelos
- Institut
Pluridisciplinaire de Recherche sur l’Environnement et les
Matériaux, Université de Pau et des Pays de l’Adour, 64000 Pau, France
| | - Curt Wentrup
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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25
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Affiliation(s)
- Curt Wentrup
- School of Chemistry and Molecular
Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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26
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Soares MIL, Nunes CM, Gomes CSB, Pinho e Melo TMVD, Fausto R. Conformational behaviour, photochemistry and flash vacuum pyrolysis of a 2-(1H-tetrazol-1-yl)thiophene. NEW J CHEM 2017. [DOI: 10.1039/c7nj02775c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The conformational and photochemical behaviour of a 2-(1H-tetrazol-1-yl)thiophene was studied using low-temperature matrix isolation infrared spectroscopy and theoretical calculations. FVP of 2-(1H-tetrazol-1-yl)thiophene afforded new thieno-fused heterocycles.
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Affiliation(s)
| | - Cláudio M. Nunes
- CQC
- Department of Chemistry
- University of Coimbra
- 3004-535 Coimbra
- Portugal
| | - Clara S. B. Gomes
- Centro de Química Estrutural
- Instituto Superior Técnico
- Universidade de Lisboa
- 1049-001 Lisboa
- Portugal
| | | | - Rui Fausto
- CQC
- Department of Chemistry
- University of Coimbra
- 3004-535 Coimbra
- Portugal
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27
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Weragoda GK, Das A, Sarkar SK, Sriyarathne HDM, Zhang X, Ault BS, Gudmundsdottir AD. Singlet Photoreactivity of 3-Methyl-2-phenyl-2H-azirine. Aust J Chem 2017. [DOI: 10.1071/ch16604] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Irradiation of 3-methyl-2-phenyl-2H-azirine (1) at 254 nm in argon matrices results in ylide 6. Similarly, laser flash photolysis (λ = 266 nm) of azirine 1 in acetonitrile yields ylide 6, which has a transient absorption with λmax at ~340 nm and a lifetime of 14 μs. Density functional theory calculations were preformed to support the characterisation of ylide 6 in solution and argon matrices. Irradiation of azirine 1 above 300 nm has previously been reported (J. Org. Chem. 2014, 79, 653) to yield triplet vinylnitrene in solution and ketenimine in cryogenic argon matrices. Thus, the photochemistry of azirine 1 is dependent on the irradiation wavelength.
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28
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Ismael A, Fausto R, Cristiano MLS. Photochemistry of 1- and 2-Methyl-5-aminotetrazoles: Structural Effects on Reaction Pathways. J Org Chem 2016; 81:11656-11663. [PMID: 27809524 DOI: 10.1021/acs.joc.6b02023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The influence of the position of the methyl substituent in 1- and 2-methyl-substituted 5-aminotetrazoles on the photochemistry of these molecules is evaluated. The two compounds were isolated in an argon matrix (15 K) and the matrix was subjected to in situ narrowband UV excitation at different wavelengths, which induce selectively photochemical transformations of different species (reactants and initially formed photoproducts). The progress of the reactions was followed by infrared spectroscopy, supported by quantum chemical calculations. It is shown that the photochemistries of the two isomers, 1-methyl-(1H)-tetrazole-5-amine (1a) and 2-methyl-(2H)-tetrazole-5-amine (1b), although resulting in a common intermediate diazirine 3, which undergoes subsequent photoconversion into 1-amino-3-methylcarbodiimide (H2N-N═C═N-CH3), show marked differences: formation of the amino cyanamide 4 (H2N-N(CH3)-C≡N) is only observed from the photocleavage of the isomer 1a, whereas formation of the nitrile imine 2 (H2N-C-═N+═N-CH3) is only obtained from photolysis of 1b. The exclusive formation of nitrile imine from the isomer 1b points to the possibility that only the 2H-tetrazoles forms can give a direct access to nitrile imines, while observation of the amino cyanamide 4 represents a novel reaction pathway in the photochemistry of tetrazoles and seems to be characteristic of 1H-tetrazoles. The structural and vibrational characterization of both reactants and photoproducts has been undertaken.
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Affiliation(s)
- A Ismael
- CCMAR and Department of Chemistry and Pharmacy, F.C.T., University of Algarve , P-8005-039 Faro, Portugal.,CQC, Department of Chemistry, University of Coimbra , P-3004-535 Coimbra, Portugal
| | - R Fausto
- CQC, Department of Chemistry, University of Coimbra , P-3004-535 Coimbra, Portugal
| | - M L S Cristiano
- CCMAR and Department of Chemistry and Pharmacy, F.C.T., University of Algarve , P-8005-039 Faro, Portugal
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29
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Nunes CM, Pinto SM, Reva I, Fausto R. Photochemistry of 3-amino-1,2-benzisoxazole: unexpected photoisomerization of an amino-spiro-2H-azirine to a 1H-diazirine. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.09.098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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30
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Nunes CM, Pinto SMV, Reva I, Fausto R. On the Photochemistry of 1,2-Benzisoxazole: Capture of Elusive Spiro-2H-azirine and Ketenimine Intermediates. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600668] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Cláudio M. Nunes
- CQC; Department of Chemistry; University of Coimbra; 3004-535 Coimbra Portugal
| | - Sandra M. V. Pinto
- CQC; Department of Chemistry; University of Coimbra; 3004-535 Coimbra Portugal
| | - Igor Reva
- CQC; Department of Chemistry; University of Coimbra; 3004-535 Coimbra Portugal
| | - Rui Fausto
- CQC; Department of Chemistry; University of Coimbra; 3004-535 Coimbra Portugal
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31
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Banerjee A, Halder D, Ganguly G, Paul A. Deciphering the cryptic role of a catalytic electron in a photochemical bond dissociation using excited state aromaticity markers. Phys Chem Chem Phys 2016; 18:25308-25314. [DOI: 10.1039/c6cp03789e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Upon photoexcitation of 5-phenyltetrazole, an electron is injected from the phenyl ring to the tetrazole ring, which performs a catalytic role in the photolytic dissociation of N2. The footprints of the “mercenary” electron are captured via dramatic changes in excited state aromaticity of the associated rings.
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Affiliation(s)
- Ambar Banerjee
- Raman Centre for Atomic Molecular and Optical Sciences Indian Association for the Cultivation of Science 2A & 2B
- India
| | - Debabrata Halder
- Raman Centre for Atomic Molecular and Optical Sciences Indian Association for the Cultivation of Science 2A & 2B
- India
| | - Gaurab Ganguly
- Raman Centre for Atomic Molecular and Optical Sciences Indian Association for the Cultivation of Science 2A & 2B
- India
| | - Ankan Paul
- Raman Centre for Atomic Molecular and Optical Sciences Indian Association for the Cultivation of Science 2A & 2B
- India
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32
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Lopes Jesus AJ, Reva I, Araujo-Andrade C, Fausto R. Conformational Switching by Vibrational Excitation of a Remote NH Bond. J Am Chem Soc 2015; 137:14240-3. [DOI: 10.1021/jacs.5b08588] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- António Jorge Lopes Jesus
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- CQC,
Faculty of Pharmacy, University of Coimbra, 3004-295 Coimbra, Portugal
| | - Igor Reva
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Cuauhtémoc Araujo-Andrade
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- Unidad Académica de Física de la Universidad Autónoma de Zacatecas, 98068 Zacatecas, Mexico
| | - Rui Fausto
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
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