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Ohashi M, Ando K, Murakami S, Michigami K, Ogoshi S. N-Heterocyclic Carbenes with Polyfluorinated Groups at the 4- and 5-Positions from [3 + 2] Cycloadditions between Formamidinates and cis-1,2-Difluoroalkene Derivatives. J Am Chem Soc 2023; 145:23098-23108. [PMID: 37749910 DOI: 10.1021/jacs.3c06331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
We herein report the formation of fluorinated N-heterocyclic carbenes (NHCFs) that bear fluorine atoms at the 4- and 5-positions of the imidazol-2-ylidene ring. Treatment of sodium N,N'-bis(aryl)formamidinates with tetrafluoroethylene followed by the addition of LiBF4 induced a [3 + 2] cycloaddition to afford 4,5-difluorinated imidazolium salts, which served as the precursors for 4,5-difluorinated NHCs. A key feature of this procedure is its applicability to other perfluorinated compounds, which enabled us to incorporate polyfluorinated functional groups at 4- and 5-positions on the imidazol-2-ylidene skeleton. Thus, employing octafluorocyclopentene and hexafluorobenzene led to the formation of 4,4,5,5,6,6-hexafluoro-1,3-diaryl-3,4,5,6-tetrahydrocyclopenta[d]imidazolium (CypIPrF·HBF4) and 4,5,6,7-tetrafluoro-1,3-diarylbenzimidazolium (BIPrF·HBF4) salts, respectively. A thorough NMR analysis of these NHCFs, their selenium adducts, and their tricarbonyl nickel complexes, (NHCF)Ni(CO)3, demonstrated that the fluorine substituents, contrary to expectations, tend to act as electron donors owing to the considerable positive mesomeric effect, while the perfluorocyclopentene-fused and tetrafluorobenzo-fused rings are pure electron acceptors due to their strong negative inductive effect. The unique and increased π-accepting character of the perfluorocyclopentene-fused and tetrafluorobenzo-fused NHCFs in both stoichiometric and catalytic reactions is further demonstrated by employing (NHCF)Ni(CO)3 and (NHCF)AuCl species, respectively. Moreover, an analysis of the % buried volume (%Vbur) values clearly suggests that the modification of the NHC backbone with polyfluorinated groups can drastically alter the electronic properties of the NHC ligand without substantially changing its steric properties. Our experimental results were further corroborated by a series of computational calculations.
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Affiliation(s)
- Masato Ohashi
- Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, Sakai 599-8531 Osaka, Japan
| | - Kota Ando
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita 565-0871 Osaka, Japan
| | - Shoichi Murakami
- Department of Chemistry, Faculty of Science, Osaka Prefecture University, Sakai 599-8531 Osaka, Japan
| | - Kenichi Michigami
- Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, Sakai 599-8531 Osaka, Japan
| | - Sensuke Ogoshi
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita 565-0871 Osaka, Japan
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2
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Synthesis and crystal structure of an iridium complex containing the novel electron-poor hybrid monoanionic ligand Ph2PCF2PO2(OiPr). Polyhedron 2022. [DOI: 10.1016/j.poly.2022.116162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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3
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Vaith J, Rodina D, Spaulding GC, Paradine SM. Pd-Catalyzed Heteroannulation Using N-Arylureas as a Sterically Undemanding Ligand Platform. J Am Chem Soc 2022; 144:6667-6673. [PMID: 35380831 PMCID: PMC9026275 DOI: 10.1021/jacs.2c01019] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Indexed: 12/03/2022]
Abstract
We report the development of ureas as sterically undemanding pro-ligands for Pd catalysis. N-Arylureas outperform phosphine ligands for the Pd-catalyzed heteroannulation of N-tosyl-o-bromoanilines and 1,3-dienes, engaging diverse coupling partners for the preparation of 2-subsituted indolines, including sterically demanding substrates that have not previously been tolerated. Experimental and computational studies on model Pd-urea and Pd-ureate complexes are consistent with monodentate binding through the nonsubstituted nitrogen, which is uncommon for metal-ureate complexes.
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Affiliation(s)
- Jakub Vaith
- Department of Chemistry, University
of Rochester, Rochester, New York 14627, United States
| | - Dasha Rodina
- Department of Chemistry, University
of Rochester, Rochester, New York 14627, United States
| | - Gregory C. Spaulding
- Department of Chemistry, University
of Rochester, Rochester, New York 14627, United States
| | - Shauna M. Paradine
- Department of Chemistry, University
of Rochester, Rochester, New York 14627, United States
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4
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Jing Y, Jiang J, Liu Y, Ke Z. Electronic and Steric Properties of N-Heterocyclic Boryl Ligands. Organometallics 2022. [DOI: 10.1021/acs.organomet.1c00685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yaru Jing
- School of Materials Science and Engineering, PCFM Lab, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Jingxing Jiang
- School of Materials Science and Engineering, PCFM Lab, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Yan Liu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangzhou 510006, China
| | - Zhuofeng Ke
- School of Materials Science and Engineering, PCFM Lab, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
- Guangdong Provincial Key Laboratory of Optical Chemicals, XinHuaYue Group, Maoming 525000, P. R. China
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5
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Reaction of polyfluoroalkyl dichlorophosphites with propargyl alcohol: synthesis and isomerization of polyfluoroalkyl di(2-propynyl) phosphites. Russ Chem Bull 2022. [DOI: 10.1007/s11172-021-3332-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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Nicholas KM. DFT analysis of the structures, dynamics and reactivity of [(Propargyl)Co2(CO)5(L)]+ Z−. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2020.121667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Ziółkowska A, Szynkiewicz N, Ponikiewski Ł. Experimental and theoretical investigation of the reactivity of [(BDI*)Ti(Cl){η 2-P(SiMe 3)-P iPr 2}] towards selected ketones. Dalton Trans 2021; 50:1390-1401. [PMID: 33433538 DOI: 10.1039/d0dt04014b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this work, we report a new type of reactivity of [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2}] (1) towards ketones (BDI* = 2,6-diisopropylphenyl-β-methyldiketiminate ligand). In the reaction of 1 with acetone, cyclopentanone or cyclohexanone, a ketone moiety is inserted into Ti-Pphosphanyl or Ti-Pphosphido bonds to form complexes with a new C-P-P moiety, providing [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2-C(Me)2O}] (2a), [(BDI*)Ti(Cl){η2-OC(Me)2P(SiMe3)-PiPr2}] (2b), [(BDI*)Ti(Cl){η2-P(SiMe3)-P(iPr)2-{C(CH2)4}O}] (3a), and [(BDI*)Ti(Cl){η2-P(SiMe3)-P(iPr)2-{C(CH2)5}O}] (4a). Starting complex 1 reacts with cyclohexanone, yielding a monocrystalline complex [{(ArN[double bond, length as m-dash]C(Me)CHC(Me)[double bond, length as m-dash]NAr)C(CH2)5O}Ti(Cl){PiPr2-P(SiMe3)C(CH2)5O}] (4d) with the insertion of two ketone molecules. Interestingly, we found that monoinserted complexes 2a and 3a may be oxidized via a reaction with AgCl, leading to elimination of the -SiMe3 group and oxidation of the titanium atom. This reaction led us to isolate the Ti(iv) complex [(BDI*)Ti(Cl){η2-P-P(iPr)2-{C(CH2)5}O}] (5) in crystalline form. To identify the kinds of products that may be formed and determine which products are the most energetically favoured ones, we conducted a thermodynamic DFT study of 1 towards acetone, cyclopentanone and cyclohexanone. Structures 2a, 2b, 3a, 3e, 4a, 4d, and 5 were characterized by X-ray crystallography, and complex 5 was also identified by NMR spectroscopy.
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Affiliation(s)
- Aleksandra Ziółkowska
- Gdansk University of Technology, Faculty of Chemistry, Department of Inorganic Chemistry, Gabriela Narutowicza Str. 11/12, 80-233 Gdansk, Poland.
| | - Natalia Szynkiewicz
- Gdansk University of Technology, Faculty of Chemistry, Department of Inorganic Chemistry, Gabriela Narutowicza Str. 11/12, 80-233 Gdansk, Poland.
| | - Łukasz Ponikiewski
- Gdansk University of Technology, Faculty of Chemistry, Department of Inorganic Chemistry, Gabriela Narutowicza Str. 11/12, 80-233 Gdansk, Poland.
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8
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Litle ED, Wilkins LC, Gabbaï FP. Ligand-enforced intimacy between a gold cation and a carbenium ion: impact on stability and reactivity. Chem Sci 2021; 12:3929-3936. [PMID: 34163662 PMCID: PMC8179465 DOI: 10.1039/d0sc05777k] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Controlling the reactivity of transition metal complexes by positioning non-innocent functionalities around the catalytic pocket is a concept that has led to significant advances in catalysis. Here we describe our efforts toward the synthesis of dicationic phosphine gold complexes of general formula [(o-Ph2P(C6H4)Carb)Au(tht)]2+ decorated by a carbenium moiety (Carb) positioned in the immediate vicinity of the gold center. While the most acidic examples of such compounds have limited stability, the dicationic complexes with Carb+ = 9-N-methylacridinium and Carb+ = [C(ArN)2]+ (ArN = p-(C6H4)NMe2) are active as catalysts for the cycloisomerization of N-propargyl-4-fluorobenzamide, a substrate chosen to benchmark reactivity. The dicationic complex [(o-Ph2P(C6H4)C(ArN)2)Au(tht)]2+, which also promotes hydroarylation and enyne cyclization reactions, displays a higher catalytic activity than its acridinium analog, indicating that the electrophilic reactivity of these complexes scales with the Lewis acidity of the carbenium moiety. These results support the role of the carbenium unit as a non-innocent functionality which can readily enhance the activity of the adjacent metal center. Finally, we also describe our efforts toward the generation and isolation of free γ-cationic phosphines of general formula [(o-Ph2P(C6H4)Carb)]+. While cyclization into phosphonium species is observed for Carb+ = [C(ArN)2]+, [C(Ph)(ArN)]+, and 9-xanthylium, [(o-Ph2P(C6H4)-9-N-methylacridinium)]+ can be isolated as an air stable, biphilic derivative with uncompromised Lewis acidic and basic properties. This work describes the synthesis of carbenium-based, γ-cationic phosphines and their coordination to Au(i) cations , leading to carbophilic catalysts whose activity is enhanced by the ligand-enforced convergence of the positively charged moieties.![]()
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Affiliation(s)
- Elishua D Litle
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Lewis C Wilkins
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - François P Gabbaï
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
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9
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Chen C, Wu F, Ji J, Jia AQ, Zhang QF. Synthesis, structural characterization and catalytic activity of chlororuthenium(II) complexes with substituted Schiff base/phosphine ancillary ligands. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2020. [DOI: 10.1515/znb-2020-0110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Treatment of [(η
6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η
6-p-cymene)RuCl2(κ
1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ
1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ
3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]
n
with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ
3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.
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Affiliation(s)
- Chong Chen
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
| | - Fule Wu
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
| | - Jiao Ji
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
| | - Ai-Quan Jia
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
| | - Qian-Feng Zhang
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
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10
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Gusarova NK, Malysheva SF, Belogorlova NA, Verkhoturova SI, Oparina LA, Arbuzova SN, Chernysheva NA, Nalibayeva AM, Bishimbayeva GK, Yas’ko SV, Trofimov BA. Synthesis of Non-Symmetric Functionalized Polyfluoroalkyl
Phosphites. RUSS J GEN CHEM+ 2020. [DOI: 10.1134/s1070363220050138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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11
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Marczenko KM, Johnson CL, Chitnis SS. Synthesis of a Perfluorinated Phenoxyphosphorane and Conversion to Its Hexacoordinate Anions. Chemistry 2019; 25:8865-8874. [PMID: 30958579 DOI: 10.1002/chem.201901333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Indexed: 12/19/2022]
Abstract
We report the synthesis and structural characterization of a neutral PV Lewis acid, P(OC6 F5 )5 , and salts containing the six-coordinate anions [P(OC6 F5 )5 F]- and [P(OC6 F5 )6 ]- . The latter anion exhibits a rare example of F-πarene interactions in both the solid and the solution phase, which has been quantitatively studied by variable-temperature (VT) NMR spectroscopy. The Lewis acid strength of P(OC6 F5 )5 has been assessed through experimental fluoride ion competition experiments and quantum-chemical calculations of its fluoride ion affinity (FIA) and global electrophilicity index (GEI). Our findings highlight the importance of considering solvent effects in electrophilicity calculations, even when neutral Lewis acids are involved, and show a rare divergence between FIA and GEI trends. The coordinating abilities of the [P(OC6 F5 )6 ]- and [P(OC6 F5 )5 F]- anions towards the trityl cation, as a prototypical electrophile, have been assessed.
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Affiliation(s)
- Katherine M Marczenko
- Chemistry Department, Dalhousie University, 6274 Coburg Road, Halifax, N. S., B3H 4R2, Canada
| | - Chloe-Louise Johnson
- Chemistry Department, Dalhousie University, 6274 Coburg Road, Halifax, N. S., B3H 4R2, Canada
| | - Saurabh S Chitnis
- Chemistry Department, Dalhousie University, 6274 Coburg Road, Halifax, N. S., B3H 4R2, Canada
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12
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Engesser TA, Transue WJ, Weis P, Cummins CC, Krossing I. As–P vs. P–P Insertion in AsP
3
: Kinetic Control of the Formation of [AsP
3
NO]
+. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Tobias A. Engesser
- Institut für Anorganische Chemie Christian‐Albrechts‐Universität zu Kiel Max‐Eyth‐Straße 2 24118 Kiel Germany
| | - Wesley J. Transue
- Department of Chemistry Massachusetts Institute of Technology 77 Massachusetts Avenue 02139 Cambridge Massachusetts USA
| | - Philippe Weis
- Institut für Anorganische und Analytische Chemie Albert‐Ludwigs‐Universität Freiburg und Freiburger Materialforschungszentrum (FMF) Albertstr. 21 79104 Freiburg Germany
| | - Christopher C. Cummins
- Department of Chemistry Massachusetts Institute of Technology 77 Massachusetts Avenue 02139 Cambridge Massachusetts USA
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie Albert‐Ludwigs‐Universität Freiburg und Freiburger Materialforschungszentrum (FMF) Albertstr. 21 79104 Freiburg Germany
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13
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Phosphines featuring a hexafluorocyclopentene skeleton: Synthesis, coordination properties, and applications for Lewis-acidic transition-metal catalysts. RESULTS IN CHEMISTRY 2019. [DOI: 10.1016/j.rechem.2019.100008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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