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Bejarano CA, Díaz JE, Cifuentes-López A, López LV, Jaramillo-Gómez LM, Buendia-Atencio C, Lorett Velásquez VP, Mejía SM, Loaiza AE. Experimental and theoretical study of the mechanism and rate constants of the sequential 5- exo-trig spirocyclization involving vinyl, aryl and N-alkoxyaminyl radicals. Org Biomol Chem 2022; 20:4141-4154. [PMID: 35521783 DOI: 10.1039/d2ob00387b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this research the sequential generation and cyclization of N-alkoxyaminyl radicals to produce 1-azaspiro[4.4]nonane, a prominent scaffold in organic and medicinal chemistry, was studied. Competition experiments in benzene at 80 °C with brominated oxime ethers using Bu3SnH as chain transfer and AIBN as the initiator generated vinyl or aryl radicals which were captured by oxime ethers, allowing approximate 5-exo-trig cyclization constants at 4.6 × 108 s-1 and 9.9 × 108 s-1 respectively to be established. Similar results were obtained by kinetic studies using the transition state theory (TST) from ab initio calculations with density functional theory (DFT) using the M06-2X, B3LYP, mPW1PW91 and TPSSh functionals in combination with the 6-311+G(d, p) basis set. Additionally, it was found that the 5-exo-trig cyclization of the N-alkoxyaminyl radical onto CC double bonds is a reversible process whose constants were determined to be in the range of 6.2 × 100 s-1 and 3.5 × 106 s-1 at 80 °C, depending on the nature of the substituents. The calculation of the radical stabilization energy (RSE) shows that the N-alkoxyaminyl radical is a very stable species and its reactivity in the addition on alkenes is governed by its nucleophilic character and the stability of the carbon-centered radical formed after cyclization. The reduction constant of the N-alkoxyaminyl radical with Bu3SnH in the gas phase at 80 °C was also estimated to be 3.4 × 100 M-1 s-1 through computational calculations. This information facilitates the rational planning of cascades and other methodologies applied to the construction of carbocyclic and aza-heterocyclic compounds.
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Affiliation(s)
- Carlos A Bejarano
- Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 11001000, Colombia. .,Departamento de Química, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá 110231, Colombia
| | - John E Díaz
- Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 11001000, Colombia.
| | | | - Lina V López
- Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 11001000, Colombia.
| | - Luz M Jaramillo-Gómez
- Departamento de Química, Facultad de Ciencias, Universidad del Valle, Cali 760032, Colombia
| | - Cristian Buendia-Atencio
- Departamento de Química, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá 110231, Colombia
| | | | - Sol M Mejía
- Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 11001000, Colombia.
| | - Alix E Loaiza
- Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 11001000, Colombia.
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Z. Zard S, Quiclet-Sire B. The Xanthate Route to Benzazepinones and Their Aza Congeners. HETEROCYCLES 2022. [DOI: 10.3987/rev-22-sr(r)9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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3
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Chao M, Wang F, Xu L, Ju Y, Chen Z, Wang B, Gong P, You J, Jin M, Shen D. Cerium Ammonium Nitrate-Mediated Access to Biaryl Lactones: Substrate Scopes and Mechanism Studies. J Org Chem 2021; 86:13371-13380. [PMID: 34533324 DOI: 10.1021/acs.joc.1c01479] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Herein we described an access to biaryl lactones from ortho-aryl benzoic acids via intramolecular O-H/C-H oxidative coupling with the commonly used cerium ammonium nitrate (CAN) as the one-electron oxidant under a thermal condition. The radical interrupting experiment suggested a radical process, while the kinetic isotope effect (KIE) showed that the C-H cleavage likely was not involved in the rate-determining step. Competitive reactions, especially the strikingly different ρ values of Hammett equations, indicated that the reaction rate was more sensitive to the electronic properties on the aryl moiety rather than the carboxylic moiety, which corresponded to the first single electron transfer (SET) step. In addition, the quite negative ρ values (-4.7) of the aryl moiety unveiled the remarkable electrophilic nature of the second intramolecular radical addition process, which was also consistent with product yields and regioselectivity. Moreover, control experiments disclosed that the single electron in the third step was also transferred to CeIV instead of molecular oxygen. Besides, the possible role of co-solvents trifluoroethanol (TFE) and its influences on the CeIV species were discussed. This work elucidated the possible mechanism by proposing the step that had more effects on the total reaction rate and the species that was responsible for the last single electron transfer.
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Affiliation(s)
- Mianran Chao
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China
| | - Fang Wang
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China
| | - Linlin Xu
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China
| | - Yanping Ju
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China
| | - Zixuan Chen
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China
| | - Bin Wang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Peiwei Gong
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China
| | - Jinmao You
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China.,Northwest Institute of Plateau Biology, Chinese Academy of Science, Xining 810001, P.R. China
| | - Ming Jin
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China
| | - Duyi Shen
- Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P.R. China
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4
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Theoretical insights into the direct radical scavenging activities of 8-hydroxyquinoline: Mechanistic, thermodynamic and kinetic studies. COMPUT THEOR CHEM 2021. [DOI: 10.1016/j.comptc.2021.113174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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5
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Hilche T, Reinsberg PH, Klare S, Liedtke T, Schäfer L, Gansäuer A. Design Platform for Sustainable Catalysis with Radicals: Electrochemical Activation of Cp 2 TiCl 2 for Catalysis Unveiled. Chemistry 2021; 27:4903-4912. [PMID: 33085978 PMCID: PMC7986168 DOI: 10.1002/chem.202004519] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Indexed: 12/17/2022]
Abstract
The combination of synthesis, rotating ring-disk electrode (RRDE) and cyclic voltammetry (CV) measurements, and computational investigations with the aid of DFT methods shows how a thiourea, a squaramide, and a bissulfonamide as additives affect the Eq Cr equilibrium of Cp2 TiCl2 . We have, for the first time, provided quantitative data for the Eq Cr equilibrium and have determined the stoichiometry of adduct formation of [Cp2 Ti(III)Cl2 ]- , [Cp2 Ti(III)Cl] and [Cp2 Ti(IV)Cl2 ] and the additives. By studying the structures of the complexes formed by DFT methods, we have established the Gibbs energies and enthalpies of complex formation as well as the adduct structures. The results not only demonstrate the correctness of our use of the Eq Cr equilibrium as predictor for sustainable catalysis. They are also a design platform for the development of novel additives in particular for enantioselective catalysis.
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Affiliation(s)
- Tobias Hilche
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| | - Philip H. Reinsberg
- Institut für Physikalische und Theoretische Chemie, Universität BonnRömerstraße 16453117BonnGermany
| | - Sven Klare
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| | - Theresa Liedtke
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| | - Luise Schäfer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
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6
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Zard SZ. The Xanthate Route to Indolines, Indoles, and their Aza Congeners. Chemistry 2020; 26:12689-12705. [DOI: 10.1002/chem.202001341] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/17/2020] [Indexed: 12/25/2022]
Affiliation(s)
- Samir Z. Zard
- Laboratoire de Synthèse Organique, UMR 7652 Ecole Polytechnique 91128 Palaiseau France
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7
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Navarro-Vázquez A, Domínguez D. Stereoelectronic constraints in the aryl radical cylization of phenethylenamides. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.151871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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8
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Mühlhaus F, Weißbarth H, Dahmen T, Schnakenburg G, Gansäuer A. Merging Regiodivergent Catalysis with Atom-Economical Radical Arylation. Angew Chem Int Ed Engl 2019; 58:14208-14212. [PMID: 31394024 PMCID: PMC6852184 DOI: 10.1002/anie.201908860] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Indexed: 12/11/2022]
Abstract
A titanocene-catalyzed regiodivergent radical arylation is described that allows access to either enantiomerically pure tetrahydroquinolines or indolines from a common starting material. The regioselectivity of epoxide opening that results in the high selectivity of heterocycle formation is controlled by two factors, the absolute configuration of the enantiopure ligands of the (C5 H4 R)2 TiX2 catalyst and the inorganic ligand X (X=Cl, OTs). The overall reaction is atom-economical and constitutes a radical Friedel-Crafts alkylation.
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Affiliation(s)
- Felix Mühlhaus
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| | - Hendrik Weißbarth
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| | - Tobias Dahmen
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| | - Gregor Schnakenburg
- Institut für Anorganische ChemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
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9
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Mühlhaus F, Weißbarth H, Dahmen T, Schnakenburg G, Gansäuer A. Merging Regiodivergent Catalysis with Atom‐Economical Radical Arylation. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201908860] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Felix Mühlhaus
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Hendrik Weißbarth
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Tobias Dahmen
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Gregor Schnakenburg
- Institut für Anorganische Chemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
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10
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Richrath RB, Olyschläger T, Hildebrandt S, Enny DG, Fianu GD, Flowers RA, Gansäuer A. Cp 2 TiX Complexes for Sustainable Catalysis in Single-Electron Steps. Chemistry 2018; 24:6371-6379. [PMID: 29327511 DOI: 10.1002/chem.201705707] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Indexed: 12/18/2022]
Abstract
We present a combined electrochemical, kinetic, and synthetic study with a novel and easily accessible class of titanocene catalysts for catalysis in single-electron steps. The tailoring of the electronic properties of our Cp2 TiX-catalysts that are prepared in situ from readily available Cp2 TiX2 is achieved by varying the anionic ligand X. Of the complexes investigated, Cp2 TiOMs proved to be either equal or substantially superior to the best catalysts developed earlier. The kinetic and thermodynamic properties pertinent to catalysis have been determined. They allow a mechanistic understanding of the subtle interplay of properties required for an efficient oxidative addition and reduction. Therefore, our study highlights that efficient catalysts do not require the elaborate covalent modification of the cyclopentadienyl ligands.
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Affiliation(s)
- Ruben B Richrath
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Str. 1, 53121, Bonn, Germany
| | - Theresa Olyschläger
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Str. 1, 53121, Bonn, Germany
| | - Sven Hildebrandt
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Str. 1, 53121, Bonn, Germany
| | - Daniel G Enny
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Godfred D Fianu
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Robert A Flowers
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Str. 1, 53121, Bonn, Germany
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11
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Zhang Z, Martinez H, Dolbier WR. Photoredox Catalyzed Intramolecular Fluoroalkylarylation of Unactivated Alkenes. J Org Chem 2017; 82:2589-2598. [DOI: 10.1021/acs.joc.6b03012] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zuxiao Zhang
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Henry Martinez
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - William R. Dolbier
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
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12
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Ceyhan S, Cetinkaya Y, Akdag A, Balci M. Regioselectivity observed in manganese(III) acetate mediated addition of acetylacetone to various alkenes: mechanistic and theoretical studies. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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Hildebrandt S, Gansäuer A. Synthesis of Dihydropyrrolizine and Tetrahydroindolizine Scaffolds from Pyrroles by Titanocene(III) Catalysis. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603985] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sven Hildebrandt
- Kekulé-Institut für Organische Chemie und Biochemie; Universität Bonn; Gerhard-Domagk-Str. 1 53121 Bonn Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie; Universität Bonn; Gerhard-Domagk-Str. 1 53121 Bonn Germany
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14
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Synthesis of Dihydropyrrolizine and Tetrahydroindolizine Scaffolds from Pyrroles by Titanocene(III) Catalysis. Angew Chem Int Ed Engl 2016; 55:9719-22. [DOI: 10.1002/anie.201603985] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/01/2016] [Indexed: 01/02/2023]
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15
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Yang Z, Luo S, Wei Z, Ye T, Spinney R, Chen D, Xiao R. Rate constants of hydroxyl radical oxidation of polychlorinated biphenyls in the gas phase: A single-descriptor based QSAR and DFT study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 211:157-164. [PMID: 26748251 DOI: 10.1016/j.envpol.2015.12.044] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/21/2015] [Accepted: 12/21/2015] [Indexed: 06/05/2023]
Abstract
The second-order rate constants (k) of hydroxyl radical (·OH) with polychlorinated biphenyls (PCBs) in the gas phase are of scientific and regulatory importance for assessing their global distribution and fate in the atmosphere. Due to the limited number of measured k values, there is a need to model the k values for unknown PCBs congeners. In the present study, we developed a quantitative structure-activity relationship (QSAR) model with quantum chemical descriptors using a sequential approach, including correlation analysis, principal component analysis, multi-linear regression, validation, and estimation of applicability domain. The result indicates that the single descriptor, polarizability (α), plays an important role in determining the reactivity with a global standardized function of lnk = -0.054 × α ‒ 19.49 at 298 K. In order to validate the QSAR predicted k values and expand the current k value database for PCBs congeners, an independent method, density functional theory (DFT), was employed to calculate the kinetics and thermodynamics of the gas-phase ·OH oxidation of 2,4',5-trichlorobiphenyl (PCB31), 2,2',4,4'-tetrachlorobiphenyl (PCB47), 2,3,4,5,6-pentachlorobiphenyl (PCB116), 3,3',4,4',5,5'-hexachlorobiphenyl (PCB169), and 2,3,3',4,5,5',6-heptachlorobiphenyl (PCB192) at 298 K at B3LYP/6-311++G**//B3LYP/6-31 + G** level of theory. The QSAR predicted and DFT calculated k values for ·OH oxidation of these PCB congeners exhibit excellent agreement with the experimental k values, indicating the robustness and predictive power of the single-descriptor based QSAR model we developed.
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Affiliation(s)
- Zhihui Yang
- Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Shuang Luo
- Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Zongsu Wei
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Tiantian Ye
- Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Richard Spinney
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Dong Chen
- Indiana University-Purdue University Fort Wayne, Fort Wayne, Indiana, 46805, USA
| | - Ruiyang Xiao
- Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China.
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16
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Rohmann K, Hölscher M, Leitner W. Can Contemporary Density Functional Theory Predict Energy Spans in Molecular Catalysis Accurately Enough To Be Applicable for in Silico Catalyst Design? A Computational/Experimental Case Study for the Ruthenium-Catalyzed Hydrogenation of Olefins. J Am Chem Soc 2015; 138:433-43. [PMID: 26713773 DOI: 10.1021/jacs.5b11997] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The catalytic hydrogenation of cyclohexene and 1-methylcyclohexene is investigated experimentally and by means of density functional theory (DFT) computations using novel ruthenium Xantphos(Ph) (4,5-bis(diphenylphosphino)-9,9-dimethylxanthene) and Xantphos(Cy) (4,5-bis(dicyclohexylphosphino)-9,9-dimethylxanthene) precatalysts [Ru(Xantphos(Ph))(PhCO2)(Cl)] (1) and [Ru(Xantphos(Cy))(PhCO2)(Cl)] (2), the synthesis, characterization, and crystal structures of which are reported. The intention of this work is to (i) understand the reaction mechanisms on the microscopic level and (ii) compare experimentally observed activation barriers with computed barriers. The Gibbs free activation energy ΔG(⧧) was obtained experimentally with precatalyst 1 from Eyring plots for the hydrogenation of cyclohexene (ΔG(⧧) = 17.2 ± 1.0 kcal/mol) and 1-methylcyclohexene (ΔG(⧧) = 18.8 ± 2.4 kcal/mol), while the Gibbs free activation energy ΔG(⧧) for the hydrogenation of cyclohexene with precatalyst 2 was determined to be 21.1 ± 2.3 kcal/mol. Plausible activation pathways and catalytic cycles were computed in the gas phase (M06-L/def2-SVP). A variety of popular density functionals (ωB97X-D, LC-ωPBE, CAM-B3LYP, B3LYP, B97-D3BJ, B3LYP-D3, BP86-D3, PBE0-D3, M06-L, MN12-L) were used to reoptimize the turnover determining states in the solvent phase (DF/def2-TZVP; IEF-PCM and/or SMD) to investigate how well the experimentally obtained activation barriers can be reproduced by the calculations. The density functionals B97-D3BJ, MN12-L, M06-L, B3LYP-D3, and CAM-B3LYP reproduce the experimentally observed activation barriers for both olefins very well with very small (0.1 kcal/mol) to moderate (3.0 kcal/mol) mean deviations from the experimental values indicating for the field of hydrogenation catalysis most of these functionals to be useful for in silico catalyst design prior to experimental work.
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Affiliation(s)
- Kai Rohmann
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University , Worringerweg 2, 52074 Aachen, Germany
| | - Markus Hölscher
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University , Worringerweg 2, 52074 Aachen, Germany
| | - Walter Leitner
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University , Worringerweg 2, 52074 Aachen, Germany.,Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1, 45470 Mülheim a.d. Ruhr, Germany
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17
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Gansäuer A, Hildebrandt S, Michelmann A, Dahmen T, von Laufenberg D, Kube C, Fianu GD, Flowers RA. Kationische Titanocen(III)-Komplexe für die Katalyse in Ein-Elektronen-Schritten. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501955] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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18
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Gansäuer A, Hildebrandt S, Michelmann A, Dahmen T, von Laufenberg D, Kube C, Fianu GD, Flowers RA. Cationic Titanocene(III) Complexes for Catalysis in Single-Electron Steps. Angew Chem Int Ed Engl 2015; 54:7003-6. [PMID: 25924582 DOI: 10.1002/anie.201501955] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 11/08/2022]
Abstract
By exploiting solvent and anion effects, [Cp2Ti](+) complexes for atom-economical catalysis in single-electron steps were developed and applied for the first time. These complexes constitute remarkably stable and active catalysts for radical arylations. The reaction kinetics and catalyst composition were studied by cyclic voltammetry and in situ IR spectroscopy.
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Affiliation(s)
- Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn (Germany).
| | - Sven Hildebrandt
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn (Germany)
| | - Antonius Michelmann
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn (Germany)
| | - Tobias Dahmen
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn (Germany)
| | - Daniel von Laufenberg
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn (Germany)
| | - Christian Kube
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn (Germany)
| | - Godfred D Fianu
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015 (USA)
| | - Robert A Flowers
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015 (USA).
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19
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Gomes F, Narbonne V, Blanchard F, Maestri G, Malacria M. Formal base-free homolytic aromatic substitutions via photoredox catalysis. Org Chem Front 2015. [DOI: 10.1039/c5qo00031a] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We developed a simple and convenient method to assemble biaryls exploiting a photoredox catalyst and visible light.
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Affiliation(s)
- Filipe Gomes
- Institut de Chimie des Substances Naturelles
- ICSN-CNRS UPR 2301
- Gif/Yvette Cedex 91198
- France
| | - Vanessa Narbonne
- Institut de Chimie des Substances Naturelles
- ICSN-CNRS UPR 2301
- Gif/Yvette Cedex 91198
- France
| | - Florent Blanchard
- Institut de Chimie des Substances Naturelles
- ICSN-CNRS UPR 2301
- Gif/Yvette Cedex 91198
- France
| | - Giovanni Maestri
- Institut de Chimie des Substances Naturelles
- ICSN-CNRS UPR 2301
- Gif/Yvette Cedex 91198
- France
- Dipartimento di Chimica
| | - Max Malacria
- Institut de Chimie des Substances Naturelles
- ICSN-CNRS UPR 2301
- Gif/Yvette Cedex 91198
- France
- Institut Parisien de Chimie Moléculaire
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20
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Gansäuer A, von Laufenberg D, Kube C, Dahmen T, Michelmann A, Behlendorf M, Sure R, Seddiqzai M, Grimme S, Sadasivam DV, Fianu GD, Flowers II RA. Mechanistic Study of the Titanocene(III)-Catalyzed Radical Arylation of Epoxides. Chemistry 2014; 21:280-9. [DOI: 10.1002/chem.201404404] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Indexed: 11/07/2022]
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21
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Salomon P, Zard SZ. A Convergent Route to Geminal Difluorosulfides and to Functionalized Difluorothiochromans, a New Family of Organofluorine Compounds. Org Lett 2014; 16:1482-5. [DOI: 10.1021/ol5002939] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Pierre Salomon
- Laboratoire
de Synthèse
Organique, CNRS UMR 7652 Ecole Polytechnique, 91128 Palaiseau, Cedex, France
| | - Samir Z. Zard
- Laboratoire
de Synthèse
Organique, CNRS UMR 7652 Ecole Polytechnique, 91128 Palaiseau, Cedex, France
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22
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Stephenson CRJ, Studer A, Curran DP. The renaissance of organic radical chemistry - deja vu all over again. Beilstein J Org Chem 2013; 9:2778-80. [PMID: 24367441 PMCID: PMC3869312 DOI: 10.3762/bjoc.9.312] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 11/26/2013] [Indexed: 11/30/2022] Open
Affiliation(s)
| | - Armido Studer
- Institute of Organic Chemistry, Westfälische Wilhelms-University Münster, 48149 Münster, Germany
| | - Dennis P Curran
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15208, USA
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