Cymantrene- and Ferrocene-Based Complexes with Perfluorinated Bridging Moieties

Roemer, Max; Schmiel, Peter; Lentz, Dieter

doi:10.1021/om2000053

Cited by 14 publications

(4 citation statements)

References 29 publications

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“…[4][5][6][7] The first group includes for example metallocenes with fluorinated alcohols or two metallocene moieties with a fluorinated bridging unit. [8][9][10][11][12] Such compounds were prepared and have been studied, e.g. for applications in tumor therapy.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, chemical reactivity and electrochemical behaviour of mono- and difluoro metallocenes

Bulfield

Maschke

Lieb

et al. 2015

Journal of Organometallic Chemistry

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Section: Introductionmentioning

confidence: 99%

Synthesis, chemical reactivity and electrochemical behaviour of mono- and difluoro metallocenes

Bulfield

Maschke

Lieb

et al. 2015

Journal of Organometallic Chemistry

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“…Cymantrene was reported to be readily substituted in various positions by Negishi-type reactions between bromocymantrenes and [IZn{(CH 2 ) 2 R f8 }] . Recently, we reported on the introduction of trifluorovinyl groups to cymantrene and to 1- , and/or 1,1′-positions , of ferrocene by Stille and Negishi-type coupling reaction with iodo precursors and tri- n -butyltrifluorovinyl stannane or trifluorovinylzinc chloride . Additionally, we reported on derivatizations on the trifluorovinyl group by nucleophilic substitution, [2 + 2] cycloadditions, and, for the case of 1,1′-bis(trifluorovinyl)ferrocene ( 5c ), the formation of fluorinated ferrocenophanes by an unusual redox-autocatalytic process.…”

Section: Introductionmentioning

confidence: 99%

Bulky-Alkyl-Substituted Bis(trifluorovinyl)ferrocenes: Redox-Autocatalytic Formation of Fluorinated Ferrocenophanes

et al. 2012

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Diastereomerically pure 1,1′-diiodoferrocenes with bulky alkyl groups in 3,3′ positions are obtained by a dilithiation strategy of 1,1′-di-tert-butylferrocene (1a) and 1,1′-bis(1-ethyl-1-methylpropyl)ferrocene (1b). The 3,3′-dilithiated species are converted to tri-n-butyltin derivatives (3a and 3b), which smoothly undergo a tin–iodine exchange reaction, yielding 1,1′-diiodo-3,3′-di-tert-butylferrocene (4a) and 1,1′-diiodo-3,3′-bis(1-ethyl-1-methylpropyl)ferrocene (4b). Negishi-type coupling reactions with trifluorovinylzinc chloride afforded the highly reactive 1,1′-bis(trifluorovinyl)ferrocenes with tert-butyl groups (5a) or 1-ethyl-1-methylpropyl groups (5b) in 3,3′-positions in excellent yields. 5a and 5b undergo under redox-conditions cyclizations to ferrocenophanes by a redox-autocatalytic mechanism. The main product four-carbon handle ferrocenophanes consist of CF2 moieties in β-positions and one carbonyl function and one C(F)(H) unit (6a and 6c) or two carbonyl functions (6b and 6d) in α-positions. A ferrocenophane with a highly fluorinated handle bearing seven fluorine atoms (6e) was isolated as a byproduct. Formation of cyclic ether derivatives by unusual intramolecular substitution of fluorine is demonstrated for the case of 6a. Several new fluorinated ferrocenes were isolated and analyzed, including 1H, 13C, and 19F nuclear magnetic resonance spectroscopies. Molecular structures of five fluorinated ferrocenophanes by tert-butyl groups were elucidated with X-ray single-crystal diffraction. Influences of the electron-withdrawing fluorous substituents and the electron-donating alkyl groups on the redox behavior of the iron center were investigated by cyclic voltammetry.

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“…The cymantrene molecule can be functionalized at the η 5 -cyclopentadienyl ligand [ 14 , 15 , 16 ], and at the tricarbonyl ligand position [ 17 , 18 ]. This structural diversity of the cymantrene molecule is the reason for its wide applicability in synthetic chemistry [ 19 , 20 , 21 ]. Recently, cymantrene derivatives have attracted considerable interest as biologically active agents.…”

Section: Introductionmentioning

confidence: 99%

Cymantrenyl-Nucleobases: Synthesis, Anticancer, Antitrypanosomal and Antimicrobial Activity Studies

et al. 2017

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The synthesis of four cymantrene-5-fluorouracil derivatives (1–4) and two cymantrene-adenine derivatives (5 and 6) is reported. All of the compounds were characterized by spectroscopic methods and the crystal structure of two derivatives (1 and 6), together with the previously described cymantrene-adenine compound C was determined by X-ray crystallography. While the compounds 1 and 6 crystallized in the triclinic P-1 space group, compound C crystallized in the monoclinic P21/m space group. The newly synthesized compounds 1–6 were tested together with the two previously described cymantrene derivatives B and C for their in vitro antiproliferative activity against seven cancer cell lines (MCF-7, MCF-7/DX, MDA-MB-231, SKOV-3, A549, HepG2m and U-87-MG), five bacterial strains Staphylococcus aureus (methicillin-sensitive, methicillin-resistant and vancomycin-intermediate strains), Staphylococcus epidermidis, and Escherichia coli, including clinical isolates of S. aureus and S. epidermidis, as well as against the protozoan parasite Trypanosoma brucei. The most cytotoxic compounds were derivatives 2 and C for A549 and SKOV-3 cancer cell lines, respectively, with 50% growth inhibition (IC50) values of about 7 µM. The anticancer activity of the cymantrene compounds was determined to be due to their ability to induce oxidative stress and to trigger apoptosis and autophagy in cancer cells. Three derivatives (1, 4 and 5) displayed promising antitrypanosomal activity, with GI50 values in the low micromolar range (3–4 µM). The introduction of the 5-fluorouracil moiety in 1 enhanced the trypanocidal activity when compared to the activity previously reported for the corresponding uracil derivative. The antibacterial activity of cymantrene compounds 1 and C was within the range of 8–64 µg/mL and seemed to be the result of induced cell shrinking.

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Cymantrene- and Ferrocene-Based Complexes with Perfluorinated Bridging Moieties

Abstract: Trifluorovinylcymantrene (1) and -ferrocene (2) form the basis of a versatile building block chemistry. Di- and trinuclear complexes with perfluorinated bridging moieties are obtained by [2+2] cycloaddition on 1 and nucleophilic substitution on the C2F3 unit of 2 with cymantrenyllithium.

Cited by 14 publications

References 29 publications

Synthesis, chemical reactivity and electrochemical behaviour of mono- and difluoro metallocenes

Synthesis, chemical reactivity and electrochemical behaviour of mono- and difluoro metallocenes

Bulky-Alkyl-Substituted Bis(trifluorovinyl)ferrocenes: Redox-Autocatalytic Formation of Fluorinated Ferrocenophanes

Cymantrenyl-Nucleobases: Synthesis, Anticancer, Antitrypanosomal and Antimicrobial Activity Studies

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