1
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Wang Z, Liu C, Huang J, Huang L, Feng H. Palladium-Catalyzed Regioselective Monofluoroallylation of Indoles with gem-Difluorocyclopropanes. Org Lett 2024; 26:6905-6909. [PMID: 39088798 DOI: 10.1021/acs.orglett.4c02554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2024]
Abstract
We present a palladium-catalyzed ring-opening reaction that induces indoles to cross-couple with gem-difluorocyclopropanes. The reaction proceeds through a domino process of C-C bond activation and C-F bond elimination, followed by C-C(sp2) coupling to produce various 2-fluoroallylindoles. This method is characterized by its high functional group tolerance, good yields and high regioselectivity, under base-free conditions. The synthetic utility of the products is illustrated by the functionalization of the NH and C2 positions of the indole scaffold.
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Affiliation(s)
- Zhenjie Wang
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China
| | - Chuang Liu
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China
| | - Junhai Huang
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China
| | - Liliang Huang
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China
| | - Huangdi Feng
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China
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2
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Jaeger R, Rachor SG, Ahrens M, Braun T. Activation of SO 2F 2 at a Rhodium PNP Pincer Complex: Ligand Supported S-F Bond Cleavage to Generate NSO 2F Derivatives. Chemistry 2024; 30:e202401571. [PMID: 38757784 DOI: 10.1002/chem.202401571] [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: 04/23/2024] [Revised: 05/16/2024] [Accepted: 05/17/2024] [Indexed: 05/18/2024]
Abstract
The κ2-(P,N)-phosphine ligand precursor NH(CH2CH2PCy2)2 can be used for the synthesis of the rhodium(I) complex [Rh(CO){ĸ3-(P,N,P)-Cy2PC2H4NHC2H4PCy2}][Cl] (1). The deprotonated complex [Rh(CO){ĸ3-(P,N,P)-Cy2PC2H4NC2H4PCy2}] (2) shows a cooperative reactivity of the PNP ligand in the activation reaction of SO2F2 to yield the rhodium fluorido complex trans-[Rh(F)(CO){ĸ2-(P,P)-Cy2PC2H4N(SO2F)C2H4PCy2}]2 (3) by S-F bond cleavage. It is remarkable that no reaction was observed when 3 was treated with hydrogen sources e. g. dihydrogen, organosilicon compounds such as triethylsilane or TMS-CF3 and different fluorine sources such as SF4 or Selectfluor®. However, the treatment of complex 3 with XeF2 in the presence of CsF resulted in the formation of the unique fluorido rhodium(III) complex cis,trans-[Rh(F)3(CO){ĸ2-(P,P)-Cy2PC2H4N(SO2F)C2H4PCy2}]2 (4). In the presence of pyridine(HF)X or BF3 the fluorido complex 3 converted into the dicationic complexes [Rh(CO){ĸ2-(P,P)-Cy2PC2H4N(SO2F)C2H4PCy2}]2[XF]2, X=HF (5) or BF3 (6), respectively.
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Affiliation(s)
- Ruben Jaeger
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Simon G Rachor
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Mike Ahrens
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Thomas Braun
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489, Berlin, Germany
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3
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Jannsen N, Reiß F, Drexler HJ, Konieczny K, Beweries T, Heller D. The Mechanism of Rh(I)-Catalyzed Coupling of Benzotriazoles and Allenes Revisited: Substrate Inhibition, Proton Shuttling, and the Role of Cationic vs Neutral Species. J Am Chem Soc 2024; 146:12185-12196. [PMID: 38647149 PMCID: PMC11066875 DOI: 10.1021/jacs.4c02679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 04/25/2024]
Abstract
Direct coupling of benzotriazole to unsaturated substrates such as allenes represents an atom-efficient method for the construction of biologically and pharmaceutically interesting functional structures. In this work, the mechanism of the N2-selective Rh complex-catalyzed coupling of benzotriazoles to allenes was investigated in depth using a combination of experimental and theoretical techniques. Substrate coordination, inhibition, and catalyst deactivation was probed in reactions of the neutral and cationic catalyst precursors [Rh(μ-Cl)(DPEPhos)]2 and [Rh(DPEPhos)(MeOH)2]+ with benzotriazole and allene, giving coordination, or coupling of the substrates. Formation of a rhodacycle, formed by unprecedented 1,2-coupling of allenes, is responsible for catalyst deactivation. Experimental and computational data suggest that cationic species, formed either by abstraction of the chloride ligand or used directly, are relevant for catalysis. Isomerization of benzotriazole and cleavage of its N-H bond are suggested to occur by counteranion-assisted proton shuttling. This contrasts with a previously proposed scenario in which oxidative N-H addition at Rh is one of the key steps. Based on the mechanistic analysis, the catalytic coupling reaction could be optimized, leading to lower reaction temperature and shorter reaction times compared to the literature.
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Affiliation(s)
- Nora Jannsen
- Leibniz-Institut
für
Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Fabian Reiß
- Leibniz-Institut
für
Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Hans-Joachim Drexler
- Leibniz-Institut
für
Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Katharina Konieczny
- Leibniz-Institut
für
Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Torsten Beweries
- Leibniz-Institut
für
Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Detlef Heller
- Leibniz-Institut
für
Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
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4
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Murata Y, Hada K, Aggarwal T, Escorihuela J, Shibata N. Transition-Metal-Free Approach for Z-Vinyl Fluorides by Hydrofluorination of Alkynes bearing SF 4 and SF 5 Groups. Angew Chem Int Ed Engl 2024; 63:e202318086. [PMID: 38206172 DOI: 10.1002/anie.202318086] [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: 11/27/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 01/12/2024]
Abstract
The synthesis of vinyl fluorides plays a crucial role in various scientific disciplines, including pharmaceutical and materials sciences. Herein, we present a direct and stereoselective hydrofluorination method for the synthesis of Z isomers of vinyl fluorides from alkynes containing unexplored SF5 and SF4 groups. Our strategy employed tetrabutylammonium fluoride (TBAF) as a fluorine source. It demonstrates high compatibility with aryls, biaryls, heteroaryls, and tert-alkyl groups, allowing facile incorporation of SF5 and SF4 groups across the triple bond without any transition-metal catalysts. This approach avoids the potential decomposition of the SF5 or SF4 units via coordination with transition metals or acidic protic sources. Remarkably, this transformation proceeded at room temperature without any additional additives, providing the Z isomer of vinyl fluorides in excellent yield and high selectivity. The presence of a water molecule as a hydrate in TBAF is essential for efficient conversion. This methodology opens new avenues for the synthesis of enchanting SF5 - and SF4 -containing fluorinated vinylic scaffolds, thereby providing advanced opportunities for novel drug discovery and fluorinated polymers.
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Affiliation(s)
- Yusuke Murata
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, Japan
| | - Kenshiro Hada
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, Japan
| | - Trapti Aggarwal
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, Japan
| | - Jorge Escorihuela
- Departamento de Química Orgánica, Universitat de València, Avda. Vicente Andrés Estellés s/n, Burjassot, 46100, Valencia, Spain
| | - Norio Shibata
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, Japan
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, Japan
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5
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Gauthier R, Paquin JF. Hydrofluorination of Alkynes: From (E) to (Z). Chemistry 2023; 29:e202301896. [PMID: 37458694 DOI: 10.1002/chem.202301896] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Indexed: 09/09/2023]
Abstract
The hydrofluorination of alkynes is an efficient synthetic route to monofluoroalkenes or difluoroalkanes. Both fluorinated motifs have found applications in medicinal chemistry and beyond. This review explores the recent advances in the hydrofluorination of diverse alkynes through various activation methods, from classical coinage metal catalysis to metal-free conditions. The range of alkynes goes from the simplest unactivated alkynes to activated ones (ynones and derivatives, ynamides, alkynyl sulfides and sulfones as much as haloalkynes). Regio- and stereoselective methods exists, but there is still room for improvement depending on the type of alkyne.
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Affiliation(s)
- Raphaël Gauthier
- PROTEO, CCVC, Département de chimie, Université Laval, 1045 avenue de la Médecine, Québec, QC, G1V 0A6, Canada
| | - Jean-François Paquin
- PROTEO, CCVC, Département de chimie, Université Laval, 1045 avenue de la Médecine, Québec, QC, G1V 0A6, Canada
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6
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Heinekamp C, Buzanich AG, Ahrens M, Braun T, Emmerling F. An amorphous Lewis-acidic zirconium chlorofluoride as HF shuttle: C-F bond activation and formation. Chem Commun (Camb) 2023; 59:11224-11227. [PMID: 37655607 DOI: 10.1039/d3cc03164k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
An exceptional HF transfer reaction by C-F bond activation of fluoropentane and a subsequent hydrofluorination of alkynes at room temperature is reported. An amorphous Lewis-acidic Zr chlorofluoride serves as heterogeneous catalyst, which is characterised by an eightfold coordination environment at Zr including chlorine atoms. The studies are seminal in establishing sustainable fluorine chemistry.
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Affiliation(s)
- Christian Heinekamp
- Department Materials Chemistry, Federal Institute for Material Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Ana Guilherme Buzanich
- Department Materials Chemistry, Federal Institute for Material Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
| | - Mike Ahrens
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Thomas Braun
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Franziska Emmerling
- Department Materials Chemistry, Federal Institute for Material Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
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7
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Sander S, Cosgrove EJ, Müller R, Kaupp M, Braun T. Hydrogen Bonding in Platinum Indolylphosphine Polyfluorido and Fluorido Complexes. Chemistry 2023; 29:e202202768. [PMID: 36327144 PMCID: PMC10107128 DOI: 10.1002/chem.202202768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/06/2022]
Abstract
The reaction of the Pt complexes cis-[Pt(CH3 )(Ar){Ph2 P(Ind)}2 ] (Ind=2-(3-methyl)indolyl, Ar=4-tBuC6 H4 (1 a), 4-CH3 C6 H4 (1 b), Ph (1 c), 4-FC6 H4 (1 d), 4-ClC6 H4 (1 e), 4-CF3 C6 H4 (1 f)) with HF afforded the polyfluorido complexes trans-[Pt(F(HF)2 )(Ar){Ph2 P(Ind)}2 ] 2 a-f, which can be converted into the fluoride derivatives trans-[Pt(F)(Ar){Ph2 P(Ind)}2 ] (3 a-f) by treatment with CsF. The compounds 2 a-f and 3 a-f were characterised thoroughly by multinuclear NMR spectroscopy. The data reveal hydrogen bonding of the fluorido ligand with HF molecules and the indolylphosphine ligand. Polyfluorido complexes 2 a-f show larger |1 J(F,Pt)|, but lower 1 J(H,F) coupling constants when compared to the fluorido complexes 3 a-f. Decreasing 1 J(P,Pt) coupling constants in 2 a-f and 3 a-f suggest a cis influence of the aryl ligands in the following order: 4-tBuC6 H4 (a) ≈4-CH3 C6 H4 (b)<Ph (c)≪4-FC6 H4 (d)<4-ClC6 H4 (e)<4-CF3 C6 H4 (f). In addition, the larger cis influence of aryl ligands bearing electron-withdrawing groups in the para position correlates with decreasing magnitudes of |1 J(F,Pt)| coupling constants. The interpretation of the experimental data was supported by quantum-chemical DFT calculations.
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Affiliation(s)
- Stefan Sander
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
| | - Elizabeth J Cosgrove
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
| | - Robert Müller
- Institut für Chemie, Technische Universität Berlin, Theoretische Chemie/Quantenchemie, Sekr.C7, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Martin Kaupp
- Institut für Chemie, Technische Universität Berlin, Theoretische Chemie/Quantenchemie, Sekr.C7, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Thomas Braun
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
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