Cymantrene Derivatives Research Articles

Photochemistry of π- and n-Donor Bifunctional Monosubstituted Derivatives of Cyclopentadienylmanganese Tricarbonyl Complexes Containing an Allyl Group and Photo- and Thermoisomerization of the Corresponding Dicarbonyl Chelates

Photochemical properties of a series of bifunctional monosubstituted derivatives of cymantrene containing a C-, N-, or O-bound π-allyl group, along with n-donating carbamate, amide, or pyridine fragments were investigated. The results obtained demonstrate that the nature and thermodynamic stability of the cyclopentadienylmanganese dicarbonyl chelates derived from bifunctional monosubstituted cymantrene derivatives depend substantially on both the nature of the functional groups and on their position in the substituent at the Cp ring. Thus, for the six-membered chelates, the thermodynamic stability increases in the series carbamates < amides < pyridines < olefins. Some of the dicarbonyl chelates studied form reversible photochromic systems due to linkage isomerization between different donating groups of the bifunctional substituent and the manganese atom with a wide range of times of thermal isomerization.

2-Pyridylmetallocenes: Part I. Electrophilic halogenation of 2-pyridylferrocene. Molecular structures of 2-pyridylferrocene and its α-brominated and -fluorinated derivatives. Synthesis of 2-pyridylruthenocene and 2-pyridylcymantrene

A new high-yield synthesis of 2-pyridylferrocene ( 1) without formation of the 1,1′-disubstituted product has been developed. Also the corresponding ruthenocene and cymantrene derivatives [C 5H 4(2-C 5H 4N)]ML n (ML n = Ru(C 5H 5) ( 2), Mn(CO) 3 ( 3)) were prepared and fully characterized. Ortho-lithiation of 1 followed by electrophilic halogenation yielded [C 5H 3X(2-C 5H 4N)]Fe(C 5H 5) [X = F ( 4), Cl ( 5), Br ( 6), I ( 7)], with 4 only being the second reported and first fully characterized fluoroferrocene. The molecular structures of 1, 4 and 6 have been determined by X-ray crystallography.

ChemInform Abstract: Regioselective Synthesis of Some Functionally 1,2-Disubstituted Cymantrene Derivatives (III) - (VI).

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Protease-Activatable Organometal−Peptide Bioconjugates with Enhanced Cytotoxicity on Cancer Cells

Over the past years, numerous promising new metalorganic lead structures have been developed exhibiting highly active cytostatic properties. However, the efficiency of such chemotherapeutics in the treatment of tumors is often limited by their low therapeutic index due to their short half-life, lack of tumor selectivity, and associated side effects. Furthermore, the membrane barrier often restricts their cellular uptake by passive diffusion. In this contribution, we describe the synthesis, cellular uptake, and biologic activity of a series of cymantrene-peptide conjugates. Cymantrene CpMn(CO)(3) is a robust organometallic group, which is stable in air and water and easy to functionalize. In this work, some new cymantrene derivatives with different linkers between the half-sandwich complex and the carboxylate group were attached to the cell-penetrating peptide sC18 that should act as a transporter for the metal moiety. All conjugates were characterized for their cytotoxic activity on human breast adenocarcinoma cells (MCF-7) and human colon carcinoma cells (HT-29). We found that bioconjugates bearing two cymantrene groups were more active than the monofunctionalized ones. By the introduction of a cathepsin B cleavage site next to the organometallic group, the biologic activity could be in increased even further. Fluorescence microscopy studies and apoptosis assays gave preliminary hints on the mode of action of these systems.

Polymer and oligomer phosphazene cymantrene derivatives as solid state precursors of nanostructured manganese pyrophosphate

Pyrolysis under air at 800 °C, of the cyclic N3P3[OC6H4PPh2·Mn(CO)2(η-MeC5H4)]6 (1) and the polymer {[NP(O2C12H8)]0.5[NP(OC6H4COOPrn)(OC6H4PPh2·Mn(CO)2(η-MeC5H4))]0.5}n (2) phosphazene with pendant OC6H4PPh2·Mn(CO)2(η-MeC5H4) units affords nanostructured Mn2P2O7. The morphology of the pyrolytic products is highly dependent on the phosphazene support. Dense structures were observed from pyrolysis of cyclic (1) while most porous materials were obtained from pyrolysis of polymer (2). The new polymeric complex (2) was prepared from reaction of the phosphine containing polymer {[NP(O2C12H8)]0.5[NP(OC6H4COOPrn)(OC6H4PPh2)]0.5}n and the photochemically generated [Mn(THF)(CO)2(η-MeC5H4)] and was fully characterized.

Synthesis of Novel Planar Chiral Ferrocene and Cyclopentadienyl Manganese Tricarbonyl Derivatives and Their Use as Chiral Ligands in the Palladium‐Catalyzed Asymmetric Allylic Alkylation.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of novel planar chiral ferrocene and cyclopentadienyl manganese tricarbonyl derivatives and their use as chiral ligands in the palladium-catalyzed asymmetric allylic alkylation

We have shown that cymantrene derivatives are better P,N-chelate ligands for palladium-catalyzed allylic alkylation than ferrocenes, which have a similar pentagonal ligand structure to cymantrene derivatives. In particular, the PPh 3-substituted cymantrene gave a higher enantioselectivity (>98%).

Thermal and Catalytic Reactions of Diazoacetylmetallocenes with [60]Fullerene

Diazoacetyl derivatives of ferrocene (2) and cymantrene (4) were submitted to thermal and dirhodium(II)tetraacetate catalyzed reactions with [60]fullerene (1). Thermal reaction of 2 afforded methanofullerene 3a and fulleroids 3b,c in variable amounts according to the reaction conditions, while 4 gave the methanofullerene 6 and the dihydrofuranofullerene 5 in ca. 1:1 ratio. Rh2(OAc)4-catalyzed reaction of 2 and 4 with C60 selectively afforded the corresponding methanofullerene derivatives 3a and 6, respectively, in high yields.

Cymantrene derivatives of oligomers and polyphosphazenes containing benzylcyanide spacer

The reaction of HOC 6 H 4 CH 2 CN (1), N 3 P 3 -(O 2 C 12 H 8 ) 2 (OC 6 H 4 CH 2 CN) 2 (2), and the random copolymer [{NP(O 2 C 12 H 8 )} 0.55 {NP(OC 6 H 4 CH 2 CN) 2 } 0.2 {NP(OC 6 H 4 -CH 2 CN)(OC 6 H 5 )} 0.25 ] n (3) with the in THF UV-irradiated precursor CH 3 -C 5 H 4 Mn(CO) 2 THF (4) affords the new compounds CH 3 -C 5 H 4 Mn(CO) 2 NCCH 2 C 6 H 4 OH (5), N 3 P 3 -(O 2 C 12 H 8 ) 2 [(OC 6 H 4 CH 2 CN.CH 3 -C 5 H 4 Mn(CO) 2 ] 2 (6), and the copolymer-[{NP(O 2 C 12 H 8 )} 0.55 {NP(OC 6 H 4 CH 2 CN. CH 3 C 5 H 4 Mn(CO) 2 ) 2 } 0.2 {NP(OC 6 H 4 -CH 2 CN.CH 3 C 5 H 4 Mn(CO) 2 )(OC 6 H 5 )} 0.25 ] n (7), respectively. The weak σ coordination of the cymantrene toward the nitrile moiety is indicated by spectroscopic data. Thermal analysis of the compounds using DSC and DTA techniques indicates that the incorporation of the organometallic fragment in the copolymer produces promissory material which leaves high amount of residues after pyrolisis. Incorporation of the organometallic fragments to the polymer does not produce an improved conductivity than the insulator polymer without manganese.

Electron Impact Mass Spectra Data Processing for Evaluation of Gas-Phase Reactivity of Cymantrene (Tricarbonyl η5-Cyclopentadienylmanganese) Derivatives

The experimental and information indices of cymantrene derivatives were calculated from their electron impact mass spectra. Correlations were found between some of the indices and the structural and bonding properties of the molecules.

The mechanism of substitution of cymantrene derivatives by phosphines and phosphites

The kinetics of the thermal substitution of (η 5-C 5H 4C(O)CH 3)Mn(CO) 2SC 4H 8, (η 1:η 5-C 5H 4C(O)CH 2SCH 3)Mn(CO) 2 and (η 1:η 5-C 5H 4C(O)CH 2CH 2SCH 3)Mn(CO) 2 by phosphines and phosphites have been measured in toluene and xylene. A proposed dissociative mechanism involving cleavage of the manganese–sulfur bonds as the rate-determining step is supported by the activation parameters obtained.

The degree of fragmentation of metallocomplexes with cleavage of the metal-ligand bond

A new method for estimating the degree of fragmentation of metallocomplexes under electron impact with cleavage of the metal-ligand bond was suggested. The method is based on mass spectrometric data. Using a representative selection of 67 organometallic compounds of different classes such as metal carbonyls, metallocenes, and cymantrene and bensenechrometricarbonyl derivatives, a correlation between the degree of fragmentation and the dissociation energy of metal-ligand bonds was developed. The correlation is evidence that the parameter can be used for quantitative estimation of the reactivity of metallocomplexes in the gas phase.

Coordination chemistry of perhalogenated cyclopentadienes and alkynes—XX. Synthesis of bi- and trimetallic cymantrene derivatives with silver or gold containing ring substituents. First observation of oxidative addition of a halogen-cyclopentadienyl bond to a Ni 0 fragment

Treatment of the perhalogenated cymantrenes [C 5X 4Br]Mn(CO) 3 (X = Cl, Br) with butyl lithium and Au(PPh 3)Cl yields, depending on the reaction conditions, the bi- or trimetallic σ, π-bridged cyclopentadienyl complexes [C 5X 5− n (AuPPh 3) n ]Mn(Co) 3 with n = 1 or 2. Similarly, the bimetallic complexes [C 5Cl 4(AgPPh 3)]Mn(CO) 3 and [C 5Cl 4(AuCN′Bu)]Mn(CO) 3 can be obtained. Addition of Ni[PBu 3] 2(C 2H 4) to [C 5Cl 4(AuPBu 3)]Mn(CO) 3 generated in situ results in oxidative addition of one ring CCl bond to Ni 0 to give [C 5Cl 3(AuPBu 3)[Ni(PBu 3) 2Cl]]Mn(CO) 3, the first complex with three different metals attached to one cyclopentadienyl ring. When the lithium cymantrenyl thiolates [C 5Cl 3X(SLi)]Mn(CO) 3 (X = Cl, Li or SLi) are treated with Au(PPh 3)Cl, the gold thiolates [C 5Cl 3Y(SAuPPh 3)]Mn(CO) 3 with Y = Cl, AuPPh 3 or SAuPPh 3 are formed.

Synthesis of novel liquid crystalline organometallic polymers

Abstract

Koordinationschemie π-gebundener Cyclopentadienyl-Chalcogeno-Ether, II. Palladium(II)- und Platin(II)-Komplexe von [C5(SMe)5]Mn(CO)3, [C5Cl2(SMe)3]Mn(CO)3 und [C5Cl2(SMe)2(PPh2)]Mn(CO)3./ Coordination Chemistry of π-Bonded Cyclopentadienyl Chalcogeno Ethers, II. Palladium(II) and Platinum(II) Complexes of [C5(SMe)5]Mn(CO)3, [C5Cl2(SMe)3]Mn(CO)3 and [C5Cl2(SMe)2(PPh2)]Mn(CO)3

Abstract Treatment of the cymantrene thioether [C5(SMe)5]Mn(CO)3 (IIb) with Na2PdCl4 or K2PtCl4 yields the bimetallic chelate complexes [C5(SMe)5]Mn(CO)3*MCl2 (M = Pd (2) or Pt (3)). Similarly, the S,P-chelate complexes [C5Cl2(SR)2(PPh2)]Mn(CO)3*PdCl2 (R = Me (4a), Ph (4b)) can be obtained from the corresponding mononuclear cymantrene derivatives and Na2PdCl4 or (PhCN)2PdCl2. Analysis of the 1H NMR spectra only allows for the Pt complex the identification of one meso form, which seems to be favoured by 2:1, together with the D,L forms. The crystal structures of [C5Cl2(SMe)3]Mn(CO)3*PdCl2(1, C11H9Cl4MnO3PdS3, triclinic, P1̄, a = 7.617(3) Å , b = 10.528(4) Å ,c = 12.473(5) Å , α = 72.95(3)°, β = 84.94(3)°, γ = 88.75(3)°, V = 952.6(6) Å3, Z = 2), 2 (C13H15Cl2MnO3PdS5, orthorhombic, Pn21/c, a = 12.739(5) Å , b = 9.992(3) Å , c = 16.884(5) Å , V = 2149(1) Å, Z = 4), and 4 (C23H18Cl6MnO3PPdS2, monoclinic, P21/c, a = 13.199(4) Å , b = 29.198(11) Å , c = 15.921(7) , β - 101.41(3)°, V = 6015(4) Å3, Z = 8) are reported and compared with each other and other bimetallic metallocene phosphine and thioether derivatives.

Synthesis and isomerism of methoxyallene derivatives of cymantrene

All of the three isomeric complexes possible for monosubstituted allenes were obtained by the interaction of 1-methoxypropadiene with CpMn(CO)3 under UV irradiation or with CpMn(CO)2(THF). The complexes were isolated as individual compounds and characterized by IR and1H and13C NMR spectroscopy.

Synthesis and properties of mono- and bis[2-(dimethylaminomethyl)]cymantrenyl derivatives of ytterbium

The reaction of [2-(dimethylaminomethyl)]cymantrenyl]lithium with ytterbium diiodide affords [2-(dimethylaminomethyl)cymantrenyl]ytterbium iodide or bis[2-(dimethylaminomethyl)cymantrenyl]ytterbium depending on the ratio of the starting reactants. Reactions of these complexes with a series of electrophiles (H2O, Me3SiCl, MeCOCl, HgCl2, PhCOCl) were studied and the corresponding derivatives of cymantrene were prepared in high yields.

Tc‐99m‐markierung von cymantren‐analogen verbindungen mit verschiedenen substituenten ‐ ein neuer zugang zu Tc‐99m radiodiagnostika

AbstractThe Technetium‐analogues of Cymantrene derivatives containing different side chains can be labelled with Tc‐99m in a simple manner starting from labelled pertechnetate.For the synthesis a solution of a ferrocene derivative with the wanted side chain, Tc 99m‐pertechnetate and a carbonyl‐donator like Mn(CO)5Br are heated at 150°C in a small glass vessel. There after the labelled cytectrene derivative is separated from by‐products by chromatographic methods. The radiochemical yields are between 15–95%. ‐ Some of the compounds showed a remarkable brain affinity with a high Tc‐99m‐concentration ratio brain/blood.

ChemInform Abstract: Reactions of Vinylidene and Allenylidene Cymantrene Derivatives with Isonitriles.

AbstractThe isocyanides (II) insert into the M=C bond of the carbene‐Mn complex (I) to give highly reactive keteneimine complexes which on addition of H2O (III) convert to the π‐complexes (IV) of isocinnamic acid amides.

Reactions of vinylidene and allenylidene cymantrene derivatives with isonitriles

Isocyanides (RNC) insert into the MC bond in Cp(OC) 2MnCCHPh (I), to give the intermediates Cp(OC) 2Mn(RNCCHPh), R = t-Bu (II), C 6H 11 (III), CH 2Ph (IV). The reaction of II–IV with H 2O gives Cp(OC) 2Mn[π- cis- Ph(H)CC(H)C(O)NHR], R = t-Bu (V), C 6H 11 (VI), CH 2Ph (VII). Reaction of III with Et 2NH forms Cp(OC) 2Mn[π-Ph(H)CCC(NEt 2)NHC 6H 11], which upon reaction with H 2O yields VI. The possibility of eliminating π-olefin ligands from V or VII by reaction with n-donors (Py, PPh 3) is shown. Reaction of Cp(OC) 2MnCCCPh 2 (VIII) with t-BuNC gives Cp(OC) 2Mn[π-Ph 2CCCHC- (O)NH-t-Bu] (IX).