1
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Miri M, Taherpour AA, Wentrup C. Nitrile Imine Cyclizations and Rearrangements: N-Phenyl- C-styrylnitrile Imine and N-Phenyl- C-phenylethynylnitrile Imine. J Org Chem 2024; 89:9360-9370. [PMID: 38867613 DOI: 10.1021/acs.joc.4c00570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
The formation and rearrangements of nitrile imines are of ongoing synthetic and theoretical interest. In this paper, we report a computational investigation at the M06/6-311 + G(d,p) level of the formation and rearrangement of propargylic N-phenyl-C-styrylnitrile imine 3 from 2-phenyl-5-styryltetrazole 1 by flash vacuum pyrolysis (FVP). Nitrile imine 3 cyclizes to 3aH-3-styrylindazole 4, which is also generated by H-shifts in the FVP of 3-styrylindazole 8. Tautomerization of 4 and N2-elimination afford cyclohexadienylidene 14, which by cyclization followed by H-shifts yields the primary pyrolysis product, 3-phenylindene 5. An alternate path via 7aH-3-styrylindazole, phenyl(styryl)diazomethane, and phenyl(styryl)carbene is potentially possible. The analogous pyrolysis of 2-phenyl-5-phenylethynyltetrazole 1' afforded cyclopenta[fg]fluorene and cyclopenta[def]phenanthrene via N-phenyl-C-phenylethynylnitrile imine 3' and 3aH-3-phenylethynylindazole 4'. In both cases, 3 and 3', rearrangement to diazocyclohexadienes and cyclohexadienylidenes (e.g., 14) is energetically preferred over alternate aryldiazomethane and arylcarbene intermediates.
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Affiliation(s)
- Maryam Miri
- Department of Organic Chemistry, Faculty of Chemistry, Razi University, Kermanshah 67149-67346, Iran
| | - Avat Arman Taherpour
- Department of Organic Chemistry, Faculty of Chemistry, Razi University, Kermanshah 67149-67346, Iran
| | - Curt Wentrup
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane 4072, Queensland, Australia
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2
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Mirzaei MS, Wentrup C. Formation of (Aza)fulvenallene, Cyanocyclopentadiene, and (Aza)fluorenes in the Thermal Rearrangements of Indazoles, Azaindazoles, and Homoquinolinic Anhydride. J Org Chem 2024; 89:553-564. [PMID: 38085550 DOI: 10.1021/acs.joc.3c02289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Flash vacuum pyrolysis (FVP) of pyrazoles and indazoles constitutes a valuable route to carbenes and nitrenes. In this study, we employed M062X and CCSD(T) calculations to provide a mechanistic rationale for the formation of fulvenallene and fluorenes from indazoles and the corresponding formation of azafulvenallene 15, cyanocyclopentadiene 19, and azafluorenes, e.g. 45, from azaindazoles, e.g. 12, and from homoquinolinic anhydride. The results reveal the importance of initial tautomerization in the pyrazole moiety of 7-azaindazole 12, which drives the mechanism toward 2-diazo-3-methylene-2,3-dihydropyridine 29 and hence 3-methylene-2,3-dihydropyridin-2-ylidene 26, followed by Wolff-type ring contraction to 1-azafulvenallene 15. This path has a calculated activation energy ∼10 kcal/mol lower than that for an alternate route involving ring opening to 3-diazomethylpyridine, dediazotization, and rearrangement of 3-pyridylcarbene to azacycloheptatetraene and phenylnitrene 24. FVP of 2,5-diphenyltetrazoles and phenyl(pyridyl)tetrazoles leads to nitrile imines, which cyclize to 3-phenylindazoles and -azaindazoles. Nitrogen elimination from these (aza) indazoles results in the formation of (aza) fluorenes, for which two alternate mechanisms are described: route A by rearrangement of (aza) indazoles to diazo(aza)cyclohexadienes and (aza)cyclohexadienylidenes and route B by rearrangement to diaryldiazomethanes and diarylcarbenes. Both paths are energetically feasible, but path A is preferred and corresponds to the azafluorenes obtained experimentally.
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Affiliation(s)
- M Saeed Mirzaei
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Curt Wentrup
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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3
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Chugunova E, Gazizov AS, Islamov D, Matveeva V, Burilov A, Akylbekov N, Dobrynin A, Zhapparbergenov R, Appazov N, Chabuka BK, Christopher K, Tonkoglazova DI, Alabugin IV. An Unusual Rearrangement of Pyrazole Nitrene and Coarctate Ring-Opening/Recyclization Cascade: Formal CH-Acetoxylation and Azide/Amine Conversion without External Oxidants and Reductants. Molecules 2023; 28:7335. [PMID: 37959754 PMCID: PMC10648078 DOI: 10.3390/molecules28217335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 10/20/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023] Open
Abstract
We report an unusual transformation where the transient formation of a nitrene moiety initiates a sequence of steps leading to remote oxidative C-H functionalization (R-CH3 to R-CH2OC(O)R') and the concomitant reduction of the nitrene into an amino group. No external oxidants or reductants are needed for this formal molecular comproportionation. Detected and isolated intermediates and computational analysis suggest that the process occurs with pyrazole ring opening and recyclization.
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Affiliation(s)
- Elena Chugunova
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Akad. Arbuzov St. 8, Kazan 420088, Russia; (A.S.G.); (D.I.); (V.M.); (A.B.); (A.D.); (I.V.A.)
| | - Almir S. Gazizov
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Akad. Arbuzov St. 8, Kazan 420088, Russia; (A.S.G.); (D.I.); (V.M.); (A.B.); (A.D.); (I.V.A.)
| | - Daut Islamov
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Akad. Arbuzov St. 8, Kazan 420088, Russia; (A.S.G.); (D.I.); (V.M.); (A.B.); (A.D.); (I.V.A.)
| | - Victoria Matveeva
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Akad. Arbuzov St. 8, Kazan 420088, Russia; (A.S.G.); (D.I.); (V.M.); (A.B.); (A.D.); (I.V.A.)
| | - Alexander Burilov
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Akad. Arbuzov St. 8, Kazan 420088, Russia; (A.S.G.); (D.I.); (V.M.); (A.B.); (A.D.); (I.V.A.)
| | - Nurgali Akylbekov
- Laboratory of Engineering Profile “Physical and Chemical Methods of Analysis”, Korkyt Ata Kyzylorda University, Aitekebie Str. 29A, Kyzylorda 120014, Kazakhstan; (N.A.); (R.Z.)
| | - Alexey Dobrynin
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Akad. Arbuzov St. 8, Kazan 420088, Russia; (A.S.G.); (D.I.); (V.M.); (A.B.); (A.D.); (I.V.A.)
| | - Rakhmetulla Zhapparbergenov
- Laboratory of Engineering Profile “Physical and Chemical Methods of Analysis”, Korkyt Ata Kyzylorda University, Aitekebie Str. 29A, Kyzylorda 120014, Kazakhstan; (N.A.); (R.Z.)
| | - Nurbol Appazov
- Laboratory of Engineering Profile “Physical and Chemical Methods of Analysis”, Korkyt Ata Kyzylorda University, Aitekebie Str. 29A, Kyzylorda 120014, Kazakhstan; (N.A.); (R.Z.)
- Zhakhaev Kazakh Scientific Research Institute of Rice Growing, Abay Av. 25B, Kyzylorda 120008, Kazakhstan
| | - Beauty K. Chabuka
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-3290, USA; (B.K.C.); (K.C.); (D.I.T.)
| | - Kimberley Christopher
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-3290, USA; (B.K.C.); (K.C.); (D.I.T.)
| | - Daria I. Tonkoglazova
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-3290, USA; (B.K.C.); (K.C.); (D.I.T.)
| | - Igor V. Alabugin
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Akad. Arbuzov St. 8, Kazan 420088, Russia; (A.S.G.); (D.I.); (V.M.); (A.B.); (A.D.); (I.V.A.)
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-3290, USA; (B.K.C.); (K.C.); (D.I.T.)
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4
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Saraswat M, Portela-Gonzalez A, Karir G, Mendez-Vega E, Sander W, Hemberger P. Thermal Decomposition of 2- and 4-Iodobenzyl Iodide Yields Fulvenallene and Ethynylcyclopentadienes: A Joint Threshold Photoelectron and Matrix Isolation Spectroscopic Study. J Phys Chem A 2023; 127:8574-8583. [PMID: 37734109 PMCID: PMC10591508 DOI: 10.1021/acs.jpca.3c04688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/06/2023] [Indexed: 09/23/2023]
Abstract
The thermal decomposition of 2- and 4-iodobenzyl iodide at high temperatures was investigated by mass-selective threshold photoelectron spectroscopy (ms-TPES) in the gas phase, as well as by matrix isolation infrared spectroscopy in cryogenic matrices. Scission of the benzylic C-I bond in the precursors at 850 K affords 2- and 4-iodobenzyl radicals (ortho- and para-IC6H4CH2•), respectively, in high yields. The adiabatic ionization energies of ortho-IC6H4CH2• to the X̃+(1A') and ã+(3A') cation states were determined to be 7.31 ± 0.01 and 8.78 ± 0.01 eV, whereas those of para-IC6H4CH2• were measured to be 7.17 ± 0.01 eV for X̃+(1A1) and 8.98 ± 0.01 eV for ã+(3A1). Vibrational frequencies of the ring breathing mode were measured to be 560 ± 80 and 240 ± 80 cm-1 for the X̃+(1A') and ã+(3A') cation states of ortho-IC6H4CH2•, respectively. At higher temperatures, subsequent aryl C-I cleavage takes place to form α,2- and α,4-didehydrotoluene diradicals, which rapidly undergo ring contraction to a stable product, fulvenallene. Nevertheless, the most intense vibrational bands of the elusive α,2- and α,4-didehydrotoluene diradicals were observed in the Ar matrices. In addition, high-energy and astrochemically relevant C7H6 isomers 1-, 2-, and 5-ethynylcyclopentadiene are observed at even higher pyrolysis temperatures along with fulvenallene. Complementary quantum chemical computations on the C7H6 potential energy surface predict a feasible reaction cascade at high temperatures from the diradicals to fulvenallene, supporting the experimental observations in both the gas phase and cryogenic matrices.
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Affiliation(s)
- Mayank Saraswat
- Lehrstuhl
für Organische Chemie II, Ruhr-Universität
Bochum, 44780 Bochum, Germany
| | | | - Ginny Karir
- Lehrstuhl
für Organische Chemie II, Ruhr-Universität
Bochum, 44780 Bochum, Germany
| | - Enrique Mendez-Vega
- Lehrstuhl
für Organische Chemie II, Ruhr-Universität
Bochum, 44780 Bochum, Germany
| | - Wolfram Sander
- Lehrstuhl
für Organische Chemie II, Ruhr-Universität
Bochum, 44780 Bochum, Germany
| | - Patrick Hemberger
- Laboratory
for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland
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5
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McCabe MN, Hemberger P, Campisi D, Broxterman JC, Reusch E, Bodi A, Bouwman J. Formation of phenylacetylene and benzocyclobutadiene in the ortho-benzyne + acetylene reaction. Phys Chem Chem Phys 2022; 24:1869-1876. [PMID: 34989380 DOI: 10.1039/d1cp05183k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Ortho-benzyne is a potentially important precursor for polycyclic aromatic hydrocarbon formation, but much is still unknown about its chemistry. In this work, we report on a combined experimental and theoretical study of the o-benzyne + acetylene reaction and employ double imaging threshold photoelectron photoion coincidence spectroscopy to investigate the reaction products with isomer specificity. Based on photoion mass-selected threshold photoelectron spectra, Franck-Condon simulations, and ionization cross section calculations, we conclude that phenylacetylene and benzocyclobutadiene (PA : BCBdiene) are formed at a non-equilibrium ratio of 2 : 1, respectively, in a pyrolysis microreactor at a temperature of 1050 K and a pressure of ∼20 mbar. The C8H6 potential energy surface (PES) is explored to rationalize the formation of the reaction products. Previously unidentified pathways have been found by considering the open-shell singlet (OSS) character of various C8H6 reactive intermediates. Based on the PES data, a kinetic model is constructed to estimate equilibrium abundances of the two products. New insights into the reaction mechanism - with a focus on the OSS intermediates - and the products formed in the o-benzyne + acetylene reaction provide a greater level of understanding of the o-benzyne reactivity during the formation of aromatic hydrocarbons in combustion environments as well as in outflows of carbon-rich stars.
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Affiliation(s)
- Morgan N McCabe
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands.
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Dario Campisi
- Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Jeger C Broxterman
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands.
| | - Engelbert Reusch
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Jordy Bouwman
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands.
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6
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Isor A, Hommelsheim R, Cone GW, Frings M, Petroff JT, Bolm C, McCulla RD. Photochemistry of N-Phenyl Dibenzothiophene Sulfoximine †. Photochem Photobiol 2021; 97:1322-1334. [PMID: 34022069 DOI: 10.1111/php.13456] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/18/2021] [Indexed: 01/04/2023]
Abstract
Sulfoximines are popular scaffolds in drug discovery due to their hydrogen bonding properties and chemical stability. In recent years, the role of reactive intermediates such as nitrenes has been studied in the synthesis and degradation of sulfoximines. In this work, the photochemistry of N-phenyl dibenzothiophene sulfoximine [5-(phenylimino)-5H-5λ4 -dibenzo[b,d]thiophene S-oxide] was analyzed. The structure resembles a combination of N-phenyl iminodibenzothiophene and dibenzothiophene S-oxide, which generate nitrene and O(3 P) upon UV-A irradiation, respectively. The photochemistry of N-phenyl dibenzothiophene sulfoximine was explored by monitoring the formation of azobenzene, a photoproduct of triplet nitrene, using direct irradiation and sensitized experiments. The reactivity profile was further studied through direct irradiation experiments in the presence of diethylamine (DEA) as a nucleophile. The studies demonstrated that N-phenyl dibenzothiophene sulfoximine underwent S-N photocleavage to release singlet phenyl nitrene which formed a mixture of azepines in the presence of DEA and generated moderate amounts of azobenzene in the absence of DEA to indicate formation of triplet phenyl nitrene.
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Affiliation(s)
- Ankita Isor
- Department of Chemistry, Saint Louis University, St. Louis, MO
| | - Renè Hommelsheim
- Institute of Organic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Grant W Cone
- Department of Chemistry, Saint Louis University, St. Louis, MO
| | - Marcus Frings
- Institute of Organic Chemistry, RWTH Aachen University, Aachen, Germany
| | - John T Petroff
- Department of Chemistry, Saint Louis University, St. Louis, MO
| | - Carsten Bolm
- Institute of Organic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Ryan D McCulla
- Department of Chemistry, Saint Louis University, St. Louis, MO
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7
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Bouwman J, Hrodmarsson HR, Ellison GB, Bodi A, Hemberger P. Five Birds with One Stone: Photoelectron Photoion Coincidence Unveils Rich Phthalide Pyrolysis Chemistry. J Phys Chem A 2021; 125:1738-1746. [PMID: 33616395 DOI: 10.1021/acs.jpca.1c00149] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Phthalide pyrolysis has been assumed to be a clean fulvenallene source. We show that this is only true at low temperatures, and the C7H6 isomers 1-, 2-, and 5-ethynylcyclopentadiene are also formed at high pyrolysis temperatures. Photoion mass-selected threshold photoelectron spectra are analyzed with the help of (time-dependent) density functional theory, (TD-)DFT, and equation-of-motion ionization potential coupled cluster, EOM-IP-CCSD, calculations, as well as Franck-Condon simulations of partly overlapping bands, to determine ionization energies. The fulvenallene ionization energy is confirmed at 8.23 ± 0.01 eV, and the ionization energies of 1-, 2 and 5-ethynylcyclopentadiene are newly determined at 8.27 ± 0.01, 8.49 ± 0.01 and 8.76 ± 0.02 eV, respectively. Excited state features in the photoelectron spectrum, in particular the Ã+ 2A' band of 1-ethynylcyclopentadiene, are shown to be practical to isomer-selectively detect species when the ground-state band is congested. At high pyrolysis temperatures, the C7H6 isomers may lose a hydrogen atom and yield the fulvenallenyl radical. Its ionization energy is confirmed at 8.20 ± 0.01 eV. The vibrational fingerprint of the first triplet fulvenallenyl cation state is also revealed and yields an ionization energy of 8.33 ± 0.02 eV. Further triplet cation states are identified and modeled in the 10-11 eV range. A reaction mechanism is proposed based on potential energy surface calculations. Based on a simplified reactor model, we show that the C7H6 isomer distribution is far from thermal equilibrium in the reactor, presumably because irreversible H loss competes efficiently with isomerization.
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Affiliation(s)
- Jordy Bouwman
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
| | - Helgi R Hrodmarsson
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
| | - G Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309-0215, United States
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
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8
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Li J, Liu MK, Li QS, Li ZS. Theoretical study on the photochemistry of furoylazides: Curtius rearrangement and subsequent reactions. Phys Chem Chem Phys 2020; 22:28317-28324. [PMID: 33300534 DOI: 10.1039/d0cp05539e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Organic azides are an efficient source of nitrenes, which serve as vigorous intermediates in many useful organic reactions. In this work, the complete active space self-consistent field (CASSCF) and its second-order perturbation (CASPT2) methods were employed to study the photochemistry of 2-furoylazide 1 and 3-furoylazide 5, including the Curtius rearrangement to two furylisocyanates (3 and 7) and subsequent reactions to the final product cyanoacrolein 9. Our calculations show that the photoinduced Curtius rearrangement of the two furoylazides takes place through similar stepwise mechanisms via two bistable furoylnitrenes 2 and 6. However, the decarbonylation and ring-opening process of 7 to 9 prefers a stepwise mechanism involving the 3-furoylnitrene intermediate 8, while 3 to 9 goes in a concerted asynchronous way without the corresponding 2-furoylnitrene intermediate 4. Importantly, we revealed that several conical intersections play key roles in the photochemistry of furoylazides. Our results are not only consistent and also make clear the experimental observations (X. Zeng, et al., J. Am. Chem. Soc., 2018, 140, 10-13), but additionally provide important information on the chemistry of furoylazides and nitrenes.
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Affiliation(s)
- Jian Li
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
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9
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Mendez-Vega E, Sander W, Hemberger P. Isomer-Selective Threshold Photoelectron Spectra of Phenylnitrene and Its Thermal Rearrangement Products. J Phys Chem A 2020; 124:3836-3843. [PMID: 32208698 DOI: 10.1021/acs.jpca.0c01134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The photoionization of phenylnitrene was investigated by photoion mass-selected threshold photoelectron spectroscopy in the gas phase. Flash vacuum pyrolysis of phenyl azide at 480 °C produces the nitrene, which subsequently rearranges at higher temperatures affording three isomeric cyanocyclopentadienes, in contrast to low-temperature trapping experiments. Temperature control of the reactor and threshold photoelectron spectra allows for optimizing the generation of phenylnitrene or its thermal rearrangement products, as well as obtaining vibrational information for the corresponding ions. The adiabatic ionization energies (AIE) of the triplet nitrene (3A2) to the radical cation in its lowest-energy doublet (2B2) and quartet (4A1) spin states were determined to 8.29 ± 0.01 and 9.73 ± 0.01 eV, respectively. Vibrational frequencies of ring breathing modes were measured at 500 ± 80 and 484 ± 80 cm-1 for both the [Formula: see text](2B2) and [Formula: see text](4A1) cationic states, respectively. The AIE differ from the values previously reported; hence, we revise the doublet-quartet energy splitting of the phenylnitrene radical cation to 1.44 eV, in excellent agreement with composite methods and coupled cluster calculations, but considerably higher than the literature reference (1.1 eV).
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Affiliation(s)
- Enrique Mendez-Vega
- Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Wolfram Sander
- Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
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10
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A Pincer Motif Etched into a meta-Benziporphyrin Frame. TOP ORGANOMETAL CHEM 2020. [DOI: 10.1007/3418_2020_61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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11
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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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12
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Yang Y, Deng G, Lu Y, Liu Q, Abe M, Zeng X. Photodecomposition of Thienylsulfonyl Azides: Generation and Spectroscopic Characterization of Triplet Thienylsulfonyl Nitrenes and 3-Thienylnitrene. J Phys Chem A 2019; 123:9311-9320. [PMID: 31593628 DOI: 10.1021/acs.jpca.9b03740] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The photochemistry of 2-thienylsulfonyl azide (1) and 3-thienylsulfonyl azide (6) has been disclosed by combining matrix-isolation spectroscopy with quantum chemical calculations. Two novel heteroaryl sulfonyl nitrenes, 2-thienylsulfonyl nitrene (2) and 3-thienylsulfonyl nitrene (7), have been generated during the 266 nm laser photolysis of 1 and 6, respectively. Both nitrenes in the triplet ground state have been characterized with matrix-isolation IR (15N-labeling) in solid Ar (10.0 K), N2 (10.0 K), and Ne (2.8 K) matrixes and EPR spectroscopy (2, |D/hc| = 1.452 cm-1 and |E/hc| = 0.0058 cm-1; 7, |D/hc| = 1.492 cm-1 and |E/hc| = 0.0060 cm-1) in solid toluene at 5.0 K. Upon subsequent UV-light irradiation (365 nm), no Curtius rearrangement but decomposition of 2 occurs by SO2-elimination and the concurrent formation of ring-opening product (s-Z)-4-thioxo-2-butenenitrile (3) via the intermediacy of the putative 2-thienylnitrene (4). In contrast, violet-light irradiation (400 ± 20 nm) of 7 causes SO2-elimination to yield triplet 3-thienylnitrene (8), for which the IR spectroscopic identification is supported by quantum chemical calculations at the B3LYP/6-311++G(3df,3pd) level. 3-Thienylnitrene is highly reactive, since it not only combines with SO2 to furnish 3-thienyl-N-sulfonylamine (9) but also undergoes ring-opening to (s-E)-4-thioxo-2-butenenitrile (10) under the UV-light irradiation (365 nm).
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Affiliation(s)
- Yang Yang
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Guohai Deng
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Yan Lu
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Qian Liu
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Manabu Abe
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashi-Hiroshima , Hiroshima 739-8526 , Japan
| | - Xiaoqing Zeng
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
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13
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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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14
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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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15
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Wentrup C. Nitrogen- and Sulfur-Containing Energetic Compounds. 64 Years of Fascinating Chemistry. Aust J Chem 2019. [DOI: 10.1071/ch19263] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This essay details the author’s work with high-energy molecules based on sulfur or nitrogen, or both, which started with amateur rocket propellants like zinc dust and sulfur followed by experiments with the highly sensitive compounds nitrogen trichloride and fulminating gold. Research on the inorganic and organic fulminates and the isomeric cyanates led to detailed investigations of reactive intermediates generated by flash vacuum pyrolysis or photolysis, in particular nitrenes and carbenes derived from azides, diazo compounds, triazoles, and tetrazoles and characterized in low temperature matrices.
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16
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Mieres-Perez J, Costa P, Mendez-Vega E, Crespo-Otero R, Sander W. Switching the Spin State of Pentafluorophenylnitrene: Isolation of a Singlet Arylnitrene Complex. J Am Chem Soc 2018; 140:17271-17277. [DOI: 10.1021/jacs.8b10792] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joel Mieres-Perez
- Lehrstuhl für Organische Chemie II, Ruhr Universität Bochum, 44780 Bochum, Germany
| | - Paolo Costa
- Lehrstuhl für Organische Chemie II, Ruhr Universität Bochum, 44780 Bochum, Germany
| | - Enrique Mendez-Vega
- Lehrstuhl für Organische Chemie II, Ruhr Universität Bochum, 44780 Bochum, Germany
| | - Rachel Crespo-Otero
- School of Biological and Chemical Sciences, Queen Mary University London, Mile End Road, London E1 4NS, U.K
| | - Wolfram Sander
- Lehrstuhl für Organische Chemie II, Ruhr Universität Bochum, 44780 Bochum, Germany
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17
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Abstract
The electronic structure and the rearrangements of the phenylnitrene radical cation C6H5N.+ 2.+ have been investigated at DFT and CASPT2(7,9) levels of theory. The 2B2 state has the lowest energy of five identified electronic states, and it can undergo ring expansion to the 1-azacycloheptetetraene radical cation 4.+ with an activation energy of ca. 28 kcal/mol. Ring opening and recyclization provide a route to 5-cyanocyclopentadiene radical cation 8.+, which may undergo facile 1,5-hydrogen shifts. The 2-, 3-, and 4-pyridylcarbene radical cations 31.+, 35.+ , and 39.+ interconvert with the phenylnitrene radical cation via azacycloheptatetraenes with activation barriers <35 kcal/mol. The carbene-carbene and carbene-nitrene rearrangements, ring expansions, ring contractions, ring openings (e.g., to cyanopentadienylidene 28.+), and cyclizations taking place in all these radical cations are completely analogous to the thermal and photochemical rearrangements.
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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, 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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18
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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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19
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Lucas M, Thomas AM, Kaiser RI, Bashkirov EK, Azyazov VN, Mebel AM. Combined Experimental and Computational Investigation of the Elementary Reaction of Ground State Atomic Carbon (C; 3Pj) with Pyridine (C5H5N; X1A1) via Ring Expansion and Ring Degradation Pathways. J Phys Chem A 2018. [DOI: 10.1021/acs.jpca.8b00756] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael Lucas
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
| | - Aaron M. Thomas
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
| | - Ralf I. Kaiser
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
| | | | | | - Alexander M. Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
- Samara University, Samara, 443086, Russia
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20
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Hurej K, Pawlicki M, Latos-Grażyński L. Rhodium-Induced Reversible C-C Bond Cleavage: Transformations of Rhodium(III) 22-Alkyl-m-benziporphyrins. Chemistry 2018; 24:115-126. [PMID: 29044777 DOI: 10.1002/chem.201704411] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Indexed: 11/12/2022]
Abstract
The structurally prearranged carbaporphyrins 22-methyl- and 22-ethyl-m-benziporphyrins provide the platform stabilizing aromatic rhodium(III) 22-(μ-methylene-m-benziporphyrin) and rhodium(III) 22-(μ-ethylidene-m-benziporphyrin). An intramolecular conversion facilitated by the m-phenylene reactivity and observed for both aromatic complexes efficiently leads to rhodium(III) 21-(μ-methylene)-21-carbaporphyrin and rhodium(III) 21-(μ-ethylidene)-21-carbaporphyrin. The distinctive macrocyclic environment of rhodium(III) 21-carbaporphyrin created an opportunity to trap unique organometallic transformations of inner core substituents affording the fulvene-like bond pattern or the rearrangement to 21-vinyl substituent. The one-electron reduction of the rhodium(III) carbaporphyrin anion π-radical with a (dxy )2 (dxz )2 (dyz )2 -(P.- ) electronic configuration is demonstrated. The further process of reduction of paramagnetic species triggers the ethyl migration from carbon(22) to rhodium(III), affording the diamagnetic rhodium(III) meta-benziporphyrin containing the apically coordinated σ-ethyl ligand providing an example of reversible C(sp2 )-C(sp3 ) bond cleavage.
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Affiliation(s)
- Karolina Hurej
- Department of Chemistry, University of Wrocław, ul.14 F. Joliot-Curie, 50-383, Wrocław, Poland
| | - Miłosz Pawlicki
- Department of Chemistry, University of Wrocław, ul.14 F. Joliot-Curie, 50-383, Wrocław, Poland
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21
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Feng R, Lu Y, Deng G, Xu J, Wu Z, Li H, Liu Q, Kadowaki N, Abe M, Zeng X. Magnetically Bistable Nitrenes: Matrix Isolation of Furoylnitrenes in Both Singlet and Triplet States and Triplet 3-Furylnitrene. J Am Chem Soc 2017; 140:10-13. [DOI: 10.1021/jacs.7b08957] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ruijuan Feng
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Yan Lu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Guohai Deng
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Jian Xu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Zhuang Wu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Hongmin Li
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Qian Liu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Norito Kadowaki
- Department
of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Manabu Abe
- Department
of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Xiaoqing Zeng
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
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22
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Wan H, Xu J, Liu Q, Li H, Lu Y, Abe M, Zeng X. Contrasting Photolytic and Thermal Decomposition of Phenyl Azidoformate: The Curtius Rearrangement Versus Intramolecular C–H Amination. J Phys Chem A 2017; 121:8604-8613. [DOI: 10.1021/acs.jpca.7b07969] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Huabin Wan
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| | - Jian Xu
- 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
| | - Hongmin Li
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| | - Yan Lu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| | - Manabu Abe
- Department
of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Xiaoqing Zeng
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
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23
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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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24
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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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25
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Bégué D, Santos-Silva H, Dargelos A, Wentrup C. Iminocyclohexadienylidenes: Carbenes or Diradicals? The Hetero-Wolff Rearrangement of Benzotriazoles to Cyanocyclopentadienes and 1H-Benzo[b]azirines. J Phys Chem A 2017; 121:5998-6003. [DOI: 10.1021/acs.jpca.7b05325] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Didier Bégué
- Institut des Sciences
Analytiques et de Physico-Chimie pour l’Environnement et les
Matériaux − IPREM, CNRS/Université de Pau et des Pays de l’Adour, UMR 5254, 64000 Pau, France
| | - Hugo Santos-Silva
- Institut des Sciences
Analytiques et de Physico-Chimie pour l’Environnement et les
Matériaux − IPREM, CNRS/Université de Pau et des Pays de l’Adour, UMR 5254, 64000 Pau, France
| | - Alain Dargelos
- Institut des Sciences
Analytiques et de Physico-Chimie pour l’Environnement et les
Matériaux − IPREM, CNRS/Université de Pau et des Pays de l’Adour, UMR 5254, 64000 Pau, France
| | - 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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Panja S, kundu D, Ahammed S, Ranu BC. Highly chemoselective reduction of azides to amines by Fe(0) nanoparticles in water at room temperature. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.07.076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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27
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Bhattacherjee D, Thakur V, Sharma S, Kumar S, Bharti R, Reddy CB, Das P. Iodine(III)-Promoted Ring Contractive Cyanation of Exocyclic β-Enaminones for the Synthesis of Cyanocyclopentanones. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201601208] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Dhananjay Bhattacherjee
- Natural Product Chemistry and Process Development Division; CSIR-Institute of Himalayan Bioresource Technology; Palampur 176061, H.P India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Vandna Thakur
- Natural Product Chemistry and Process Development Division; CSIR-Institute of Himalayan Bioresource Technology; Palampur 176061, H.P India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Saurabh Sharma
- Natural Product Chemistry and Process Development Division; CSIR-Institute of Himalayan Bioresource Technology; Palampur 176061, H.P India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Sandeep Kumar
- Natural Product Chemistry and Process Development Division; CSIR-Institute of Himalayan Bioresource Technology; Palampur 176061, H.P India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Richa Bharti
- Natural Product Chemistry and Process Development Division; CSIR-Institute of Himalayan Bioresource Technology; Palampur 176061, H.P India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - C. Bal Reddy
- Natural Product Chemistry and Process Development Division; CSIR-Institute of Himalayan Bioresource Technology; Palampur 176061, H.P India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Pralay Das
- Natural Product Chemistry and Process Development Division; CSIR-Institute of Himalayan Bioresource Technology; Palampur 176061, H.P India
- Academy of Scientific and Innovative Research, New Delhi, India
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28
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Shoji T, Nagai D, Tanaka M, Araki T, Ohta A, Sekiguchi R, Ito S, Mori S, Okujima T. Synthesis of 2-Aminofurans by Sequential [2+2] Cycloaddition-Nucleophilic Addition of 2-Propyn-1-ols with Tetracyanoethylene and Amine-Induced Transformation into 6-Aminopentafulvenes. Chemistry 2017; 23:5126-5136. [DOI: 10.1002/chem.201700121] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Indexed: 01/07/2023]
Affiliation(s)
- Taku Shoji
- Department of Material Science; Graduate School of Science and Technology; Shinshu University, Matsumoto; 390-8621 Nagano Japan
| | - Daichi Nagai
- Department of Material Science; Graduate School of Science and Technology; Shinshu University, Matsumoto; 390-8621 Nagano Japan
| | - Miwa Tanaka
- Department of Material Science; Graduate School of Science and Technology; Shinshu University, Matsumoto; 390-8621 Nagano Japan
| | - Takanori Araki
- Department of Material Science; Graduate School of Science and Technology; Shinshu University, Matsumoto; 390-8621 Nagano Japan
| | - Akira Ohta
- Department of Material Science; Graduate School of Science and Technology; Shinshu University, Matsumoto; 390-8621 Nagano Japan
| | - Ryuta Sekiguchi
- Graduate School of Science and Technology; Hirosaki University, Hirosaki; 036-8561 Aomori Japan
| | - Shunji Ito
- Graduate School of Science and Technology; Hirosaki University, Hirosaki; 036-8561 Aomori Japan
| | - Shigeki Mori
- Advanced Research Support Center; Ehime University, Matsuyama; 790-8577 Ehime Japan
| | - Tetsuo Okujima
- Department of Chemistry and Biology; Graduate School of Science and Engineering; Ehime University, Matsuyama; 790-8577 Ehime Japan
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29
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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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30
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Andersson H, Gräfenstein J, Isobe M, Erdélyi M, Sydnes MO. Photochemically Induced Aryl Azide Rearrangement: Solution NMR Spectroscopic Identification of the Rearrangement Product. J Org Chem 2017; 82:1812-1816. [PMID: 28068094 DOI: 10.1021/acs.joc.6b02555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photolysis of ethyl 3-azido-4,6-difluorobenzoate at room temperature in the presence of oxygen results in the regioselective formation of ethyl 5,7-difluoro-4-azaspiro[2.4]hepta-1,4,6-triene-1-carboxylate, presumably via the corresponding ketenimine intermediate which undergoes a photochemical four-electron electrocyclization followed by a rearrangement. The photorearrangement product was identified by multinuclear solution NMR spectroscopic techniques supported by DFT calculations.
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Affiliation(s)
- Hanna Andersson
- Department of Chemistry and Molecular Biology, University of Gothenburg , SE-412 96 Gothenburg, Sweden
| | - Jürgen Gräfenstein
- Department of Chemistry and Molecular Biology, University of Gothenburg , SE-412 96 Gothenburg, Sweden
| | - Minoru Isobe
- Department of Chemistry, National Sun Yat-Sen University , Kaohsiung, Taiwan
| | - Máté Erdélyi
- Department of Chemistry and Molecular Biology, University of Gothenburg , SE-412 96 Gothenburg, Sweden.,The Swedish NMR Centre , SE-413 96 Gothenburg, Sweden
| | - Magne O Sydnes
- Department of Mathematics and Natural Science, University of Stavanger , NO-4036 Stavanger, Norway
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31
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Hurej K, Pawlicki M, Latos-Grażyński L. Gold(III) Triggered Transformations of 22-Methyl-m
-benziporphyrin Involving an Effective Contraction of Benzene to Cyclopentadiene. Chemistry 2016; 23:2059-2066. [PMID: 27981629 DOI: 10.1002/chem.201604458] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Karolina Hurej
- Department of Chemistry; University of Wrocław; ul.14 F. Joliot-Curie 50-383 Wrocław Poland
| | - Miłosz Pawlicki
- Department of Chemistry; University of Wrocław; ul.14 F. Joliot-Curie 50-383 Wrocław Poland
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32
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Chen Y, Gutmann B, Kappe CO. Continuous-Flow Electrophilic Amination of Arenes and Schmidt Reaction of Carboxylic Acids Utilizing the Superacidic Trimethylsilyl Azide/Triflic Acid Reagent System. J Org Chem 2016; 81:9372-9380. [DOI: 10.1021/acs.joc.6b02085] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Yuesu Chen
- Institute
of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, A-8010 Graz, Austria
| | - Bernhard Gutmann
- Research
Center
Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010 Graz, Austria
| | - C. Oliver Kappe
- Institute
of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, A-8010 Graz, Austria
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33
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Aylward N, Kvaskoff D, Becker J, Wentrup C. Rearrangements of 4-Quinolylcarbene, 3-Quinolylcarbene, and 2-Quinolylcarbene to 1-Naphthylnitrene and Cyanoindenes by Falling Solid Flash Vacuum Pyrolysis. J Org Chem 2016; 81:4609-15. [DOI: 10.1021/acs.joc.6b00444] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nigel Aylward
- School
of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Qld 4072, Australia
| | - David Kvaskoff
- School
of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Qld 4072, Australia
| | - Jürgen Becker
- Fachbereich
Chemie, Philipps-Universität, D-35037 Marburg, Germany
| | - Curt Wentrup
- School
of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Qld 4072, Australia
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34
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Wentrup C, Thétaz C, Lüerssen H, Aylward N, Kvaskoff D. Ring Contraction in Arylcarbenes and Arylnitrenes; Rearrangements of 1- and 3-Isoquinolylcarbenes and 2-Naphthylnitrene to Cyanoindenes. J Org Chem 2016; 81:4601-8. [DOI: 10.1021/acs.joc.6b00442] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Curt Wentrup
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane Qld 4072, Australia
| | - Célestin Thétaz
- Institut
de Chimie Organique, Université de Lausanne, CH-1009 Lausanne, Switzerland
| | - Holger Lüerssen
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane Qld 4072, Australia
| | - Nigel Aylward
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane Qld 4072, Australia
| | - David Kvaskoff
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane Qld 4072, Australia
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35
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Aylward N, Winter HW, Eckhardt U, Wentrup C. Triazoloazine–Diazomethylazine Valence Isomerization. [1,2,3]Triazolo[1,5-a]pyridines and 2-Diazomethylpyridines. J Org Chem 2015; 81:667-72. [DOI: 10.1021/acs.joc.5b02639] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nigel Aylward
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Hans-Wilhelm Winter
- Fachbereich Chemie der Philipps-Universität Marburg, D-35037 Marburg, Germany
| | - Ulrich Eckhardt
- Fachbereich Chemie der Philipps-Universität Marburg, D-35037 Marburg, Germany
| | - Curt Wentrup
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
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36
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Mieres-Pérez J, Mendez-Vega E, Velappan K, Sander W. Reaction of Triplet Phenylnitrene with Molecular Oxygen. J Org Chem 2015; 80:11926-31. [DOI: 10.1021/acs.joc.5b01263] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joel Mieres-Pérez
- Lehrstuhl
für Organische
Chemie II, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | - Enrique Mendez-Vega
- Lehrstuhl
für Organische
Chemie II, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | - Kavitha Velappan
- Lehrstuhl
für Organische
Chemie II, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | - Wolfram Sander
- Lehrstuhl
für Organische
Chemie II, Ruhr-Universität Bochum, D-44780 Bochum, Germany
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37
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Idec A, Szterenberg L, Latos-Grażyński L. Frompara-Benziporphyrin to Rhodium(III) 21-Carbaporphyrins: Imprinting Rh⋅⋅⋅η2-CC, Rh⋅⋅⋅η2-CO, and Rh⋅⋅⋅η2-CH Coordination Motifs. Chemistry 2015. [DOI: 10.1002/chem.201501996] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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38
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Wentrup C, Becker J, Diehl M. C15H10 and C15H12 Thermal Chemistry: Phenanthrylcarbene Isomers and Phenylindenes by Falling Solid Flash Vacuum Pyrolysis of Tetrazoles. J Org Chem 2015; 80:7144-9. [DOI: 10.1021/acs.joc.5b01007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Curt Wentrup
- Fachbereich Chemie der Philipps-Universität Marburg, D-35037 Marburg, Germany
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Jürgen Becker
- Fachbereich Chemie der Philipps-Universität Marburg, D-35037 Marburg, Germany
| | - Manfred Diehl
- Fachbereich Chemie der Philipps-Universität Marburg, D-35037 Marburg, Germany
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39
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Kvaskoff D, Becker J, Wentrup C. Azulenylcarbene and Naphthylcarbene Isomerizations. Falling Solid Flash Vacuum Pyrolysis. J Org Chem 2015; 80:5030-4. [DOI: 10.1021/acs.joc.5b00412] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David Kvaskoff
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Jürgen Becker
- Fachbereich Chemie der Philipps-Universität Marburg, D-35037 Marburg, Germany
| | - Curt Wentrup
- School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
- Fachbereich Chemie der Philipps-Universität Marburg, D-35037 Marburg, Germany
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40
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Wentrup C, Becker J, Winter HW. Falling-Solid Flash Vacuum Pyrolysis: An Efficient Preparation of Arylacetylenes. Angew Chem Int Ed Engl 2015; 54:5702-4. [DOI: 10.1002/anie.201412431] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 01/26/2015] [Indexed: 11/10/2022]
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41
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Wentrup C, Becker J, Winter HW. Falling-Solid Flash Vacuum Pyrolysis: An Efficient Preparation of Arylacetylenes. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201412431] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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