Comparison of structure,log<Emphasis Type="Italic">P</Emphasis> and P388 cytotoxicity of some phenyl and ferrocenyl cyclic chalcone analogues. Application of RP-TLC for log<Emphasis Type="Italic">P</Emphasis> determination of the ferrocenyl analogues

Cyclic chalcone analogues (2–5) and their ferrocenyl counterparts (6–10) were synthesized and their logP and P388 cyctotoxity were investigated. The structures of the newly synthesized compounds were confirmed by IR ¹H and ¹³NMR spectroscopy. Comparison of conjugation and stereochemistry of the respective derivatives showed similar characteristics compared to ones with some higher degree of conjugation in the ferrocenyl series. Comparison of logP of the ferrocenyl derivatives determined by a validated RP-TLC method showed the ferrocenyl derivatives to have higher logP _TLC. The results demonstrate that the differences in three dimensional shape, conjugation and lipophilicity do not have strong influence on the P388 cytotoxicity of the investigated phenyl (1−5) and ferrocenyl (6−10) enones.      

二茂铁四唑和二茂铁甲醛缩3-取代丙二醇衍生物的合成

以甲酰基二茂铁6为原料, 通过与NH₄OH•HCl的缩合反应得到二茂铁肟7, 再经脱水剂脱水得到二茂铁腈8, 最后在(n-C₄H₉)₃SnCl的作用下与NaN₃反应生成新化合物二茂铁四唑(9). 以甲酰基二茂铁为原料, 在对甲苯磺酸(PTSA)的催化作用下与原甲酸三甲酯反应生成二甲基二茂铁缩醛(10), 然后与(R)-(－)-3-氯-1,2-丙二醇反应得到新的二茂铁缩醛衍生物12, 12再与NaN₃发生取代反应得到新的二茂铁缩醛衍生物13. 而新的二茂铁缩醛衍生物15的合成则是先由(R)-(－)-3-氯-1,2-丙二醇与CH₃OH在NaOH的作用下生成(R)-(－)-1-甲氧基-2,3-丙二醇(14), 再由14与二甲基二茂铁缩醛(10)反应得到的. 所合成的新化合物都用MS, ¹H NMR和IR谱确证了它们的结构.     

Asymmetric Synthesis of Novel Ferrocenyl Ligands with Planar and Central Chirality

A stereogenic center at the position β to the metallocene backbone is present in ferrocenyl ligands 2 , which are interesting for asymmetric catalysis. These planar-chiral compounds are accessible for the first time by a highly diastereoselective and enantioselective synthesis (de=93–97 %; ee≥96 %) from the ferrocenyl ketones 1 . A variety of donor groups (E¹=Ph₂P⋅BH₃, SMe, SiPr; E²=SMe, STol, SePh, Ph₂P⋅BH₃, iPr₂P⋅BH₃) can be introduced as electrophiles. Tol=tolyl=CH₃C₆H₄.     

Synthesis and optical and electrochemical properties of glucose-cored ferrocenyl dendrimers

Triazole-based ferrocenyl glycoconjugates 1, 2, and 3 were synthesized by regiospecific copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) of azidoferrocenyl derivatives with glucose pentaacetylide. Higher generation ferrocenyl glycoconjugates form the stable ferrocenium cation and exhibit increased light harvesting property as revealed from cyclic voltammogram studies and ultraviolet–visible spectrum respectively due to the presence of more ferrocenyl and triazolyl units than the lower generation dendrimer.     

Synthesis,characterization and evaluation of heterobimetallic Fe(II)/Rh(I) and Fe(II)/Ru(II) complexes as catalyst precursors for hydroformylation of 1-octene

Abstract

Two new ferrocenyl iminopyridyl ligands, L1 and L2, have been synthesized and characterized using spectroscopic and analytical techniques. Both ligands were used to prepare new Rh(I) and Ru(II) ferrocenyl complexes 1–4. The structures of the complexes were confirmed using ¹H and ¹³C nuclear magnetic resonance spectroscopy, high resolution electrospray ionization mass spectrometry, and infrared spectroscopy. The complexes were tested as catalysts in the hydroformylation of 1-octene. Rh ferrocenyl complexes 1 and 4 produced aldehydes under mild conditions while the Ru-ferrocenyl complexes 2 and 3 required higher temperature and pressure for effective hydroformylation to occur. The catalysts display excellent aldehyde chemoselectivity with varying regeoselectivity depending on temperature and pressure conditions employed. At high temperatures, the Rh ferrocenyl precatalysts favor formation of branched aldehydes due to increased isomerization at high temperatures. The Ru ferrocenyl precatalysts displayed less hydroformylation activity; however, the complexes show good chemoselectivity for aldehydes with no hydrogenation products formed.     

Sterically Hindered N‐Heterocyclic Salts Utilized as Antimicrobial Agents

By the adoption of annulated ring systems for their steric bulkiness, a new series of symmetric N ‐heterocyclic imidazolium and perimidium salts were synthesized. Also, corresponding asymmetric ferrocenyl N ‐functionalized series were prepared as salts. All the reported salts were fully characterized. The reported X‐ray structure of 4,5‐diphenyl‐1,3‐dimethyl‐1H ‐imidazol‐3‐ium iodide ( 2a ) shows that it crystallized in the orthorhombic space group P 2₁2₁2₁. Low to moderate antimicrobial activities were observed with both sets of salts against important clinical isolates of Staphylococcus aureus , Bacillus subtilis , and Enterococcus faecalis and Escherichia coli , Pseudomonas aeruginosa , and Salmonella enterica . The results were benchmarked against meropenem. Both 1,3‐propyl‐1H ‐phenanthro[9,10‐d ]imidazol‐3‐ium iodide ( 3b ) and 1‐ferrocenyl‐3‐propyl‐1H ‐perimidin‐3‐ium iodide ( 9b ) showed high antimicrobial activities against all tested Gram‐positive bacterial strains, with minimum inhibitory concentration values ranging from 8 to 4 μg/mL (meropenem = 0.5–0.125 μg/mL), while all the salts showed little or no activity against Gram‐negative bacterial strains. In general, the asymmetric ferrocenyl‐containing salts exhibited higher activities than the symmetric ones.     

Structural and Spectral Characterization of Two Charge-Transfer Salts Formed by Ferrocenyl and Polyoxometalate Units

Two charge-transfer (CT) salts based on the ferrocenyl cation CpFeCpCH₂N⁺(CH₃)₃ and Keggin-type anion [PW₁₂O₄₀]³⁻ or [SiMo₁₂O₄₀]⁴⁻ with the ratio of ferrocenyl:polyanion of 3:1 or 4:1, [CpFeCpCH₂N(CH₃)₃]₃[PW₁₂O₄₀] (1) and [CpFeCp-CH₂N⁺(CH₃)₃]₄[SiMo₁₂O₄₀] (2), were synthesized in high yields (68–71%) by traditional solution synthetic method and their structures were determined by X-ray diffraction analysis. The two salts both crystallize in triclinic space group P[`1] P\overline{1} and show the close interaction of the cyclopentadienyl ligand with the surface of the polyoxometalate. The UV–Vis diffuse reflectance spectra of 1 and 2 in the solid state indicate the presence of a new absorption band at λ _max = 550 and 630 nm, respectively, attributed to charge-transfer transitions between the ferrocenyl donors and the POM acceptors. The large difference of the shapes and positions of fluorescence emission bands of salts from the start materials also suggested the occurrence of a charge transfer process between the ferrocenyl cation and polyanion.     

Electrochemistry: A Tool for Characterization of Hybrid Materials Obtained by Non-Hydrolytic Sol-Gel Route and Containing Ferrocene Derivatives

The 1,1-ferrocenediyldichlorosilane 1 was introduced into oxide matrices (SiO₂, TiO₂, Al₂O₃) by non-hydrolytic sol-gel route. In all cases some degradation of the ferrocenyl moiety occurred. The materials were immobilized onto an electrode surface as a composite film with PTFE and their cyclic voltammograms were studied. For each sample a reduction wave around –375 mV was evidenced which was attributed to the reduction of [Fe^III Cl _x ]^{3 – x} species arising from the decomposition of ferrocenyl species during the condensation process.     

Systematic Study of the Asymmetric Methoxycarbonylation of Styrene Catalyzed by Palladium Systems Containing Chiral Ferrocenyl Diphosphine Ligands

We present the first systematic study of the Pd‐catalyzed asymmetric methoxycarbonylation of styrene in the presence of chiral ferrocenyl phosphine ligands. The reaction conditions were optimized, and a screening of different catalyst precursors was performed. A number of 1,1′‐bis(phosphino)ferrocenes of the Mandyphos, Josiphos, Walphos, and Taniaphos types were tested in combination with [PdCl₂(NCPh)₂], in the presence of TsOH as the acid source. These systems afforded high enantioselectivities, although the regioselectivity of the reaction was found to be in favor of the (undesired) linear ester. The catalytic system made with the Josiphos ligand 1 gave rise to an enantiomeric excess (ee) of 86%.     

Four (2,2′‐bipyridyl)(ferrocenyl)boronium derivatives

Crystal structures are reported for four (2,2′‐bipyridyl)(ferrocenyl)boronium derivatives, namely (2,2′‐bipyridyl)(ethenyl)(ferrocenyl)boronium hexafluoridophosphate, [Fe(C₅H₅)(C₁₇H₁₅BN₂)]PF₆, (Ib), (2,2′‐bipyridyl)(tert‐butylamino)(ferrocenyl)boronium bromide, [Fe(C₅H₅)(C₁₉H₂₂BN₃)]Br, (IIa), (2,2′‐bipyridyl)(ferrocenyl)(4‐methoxyphenylamino)boronium hexafluoridophosphate acetonitrile hemisolvate, [Fe(C₅H₅)(C₂₂H₂₀BN₃O)]PF₆·0.5CH₃CN, (IIIb), and 1,1′‐bis[(2,2′‐bipyridyl)(cyanomethyl)boronium]ferrocene bis(hexafluoridophosphate), [Fe(C₁₇H₁₄BN₃)₂](PF₆)₂, (IVb). The asymmetric unit of (IIIb) contains two independent cations with very similar conformations. The B atom has a distorted tetrahedral coordination in all four structures. The cyclopentadienyl rings of (Ib), (IIa) and (IIIb) are approximately eclipsed, while a bisecting conformation is found for (IVb). The N—H groups of (IIa) and (IIIb) are shielded by the ferrocenyl and tert‐butyl or phenyl groups and are therefore not involved in hydrogen bonding. The B—N(amine) bond lengths are shortened by delocalization of π‐electrons. In the cations with an amine substituent at boron, the B—N(bipyridyl) bonds are 0.035 (3) Å longer than in the cations with a methylene C atom bonded to boron. A similar lengthening of the B—N(bipyridyl) bonds is found in a survey of related cations with an oxy group attached to the B atom.     

Syntheses and molecular structures of new ferrocenylacetylide-bridged binuclear cobalt carbonyl cluster compounds

The reaction of ferrocenylacetylide compounds with Co₂(CO)₈ at room temperature affords four complexes bearing ferrocenyl units with approximately tetrahedral (μ-alkyne)dicobalt moieties [R–(C≡C) _n –R′] [Co₂(CO)₆] _{n ′} [R?=?C₅H₅FeC₅H₄-C(CH₃)₂-C₅H₄FeC₅H₄, R′?=?H, n?=?1, n′?=?1 (1); R?=?C₅H₅FeC₅H₄ [ferrocenyl (Fc)], R′?=?–CH=CHCl, n?=?1, n′?=?1 (2); R?=?Fc, R′?=?Fc, n?=?2, n′?=?1 (3), n′?=?2 (4)]. The compounds were characterized by elemental analysis, IR, ¹H(¹³C) NMR, MS and single-crystal X-ray diffraction analysis. The X-ray analyses show that coordination of the carbon–carbon triple bond and the dicobalt unit result in the formation of a Co₂C₂ tetrahedral core, and the substituents on the acetylenic units show a distortion from linearity that reflects this coordination mode.     

Asymmetric hydrogenation of enol phosphinates catalyzed by a chiral ferrocenylphosphine-rhodium complex. Asymmetric synthesis of optically active secondary alkyl alcohols

Catalytic asymmetric synthesis of secondary alkyl alcohols (up to 78% ee) was accomplished by asymmetric hydrogenation of enol diphenylphosphinates, derived from prochiral ketones such as acetophenone, 3-methyl-2-butanone, and 2-octanone, in the presence of a cationic rhodium complex of (R)-1-[(C)-1′,2-bis(diphenylphosphino)ferrocenyl]ethanol (BPPFOH).     

Chiral ferrocenyl diphosphines for asymmetric transfer hydrogenation of acetophenone

The synthesis of new optically pure ferrocenyl diphosphines have been realized from (R)-(+)-N,N-dimethylaminoethylferrocene. Particularly, dissymmetric ferrocenyl diphosphines have been synthesized. The diphosphines have been used as ligands in asymmetric transfer hydrogenation of acetophenone in the presence of Ru catalysts.     

Electrochemical studies with dissolved and surface-confined forms of neo-pentyl-ferrocene-based polyesters utilising [NBu4][B(C6F5)4] and other electrolytes

The voltammetric oxidation at a glassy carbon electrode of a series of ferrocenyl polyesters PmF{X}, (X=T, terephthalate; N, 2,6-naphthalene dicarboxylate; B, 4,4′-biphenyl dicarboxylate) is reported in the weakly donating and low-polarity CH₂Cl₂ solvent containing [NBu₄][PF₆], [NBu₄][B(C₆F₅)₄], or 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([bmpyr][TFSA]) as the supporting electrolyte. The one electron oxidation of the ferrocenyl groups is strongly influenced by the nature of the supporting electrolyte anion. Use of the conventional [PF₆]⁻ anion or the room temperature ionic liquid (RTIL), [bmpyr][TFSA] as the supporting electrolyte, gives rise to significant oxidation product interaction (precipitation and/or adsorption) with the electrode surface. In marked contrast, diffusion-controlled, chemically and electrochemically reversible processes are observed when the weakly coordinating [B(C₆F₅)₄]⁻ is used as the anionic component of the supporting electrolyte. In this case, data obtained via cyclic voltammetry, chronoamperometry and chronocoulometry are consistent with ideal reversible one electron oxidation processes and a soluble cationic product. Diffusion coefficients of the monomers, polymers, ferrocene and decamethyferrocene are reported in the CH₂Cl₂/[NBu₄][B(C₆F₅)₄] system. Importantly, reversible potentials that are easily obtained under these conditions show that the acyl or methyl linkers, through which the ferrocenyl group is attached to the neo-pentylenediol component, tune the redox properties of the polymers. Electrochemical studies with a glassy carbon electrode modified with microcrystals of the PmFT polymer conducted in aqueous (with KCl supporting electrolyte) or neat ionic liquid ([bmpyr][TFSA]) media also are reported. Different mechanisms apply in each of these cases.     

含二茂铁的β-内酰胺的研究进展

β-内酰胺类抗生素是目前最具应用价值的抗生素, 其结构特征具有β-内酰胺环的基元结构, 该类化合物的设计、合成和立体化学研究一直是有机合成化学研究的前沿和热点领域. 二茂铁凭借其独特的结构和多样的性质, 在生物和医药方面均有广泛的应用价值. 因此, 二茂铁修饰的β-内酰胺是一类结构新颖且具有潜在生物活性的化合物. 对该类化合物的深入研究, 将对新型抗生素的研发提供重要的指导意义. 综述了近年来青霉烷类和头孢烯类β-内酰胺及单环类β-内酰胺这两大类含二茂铁取代的β-内酰胺衍生物的合成与生物活性的研究进展.     

New chiral ferrocenyl P,S-ligands for highly diastereo- and enantioselective Ag(I)-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides

A new family of chiral ferrocenyl P,S-ligands incorporating an indole ring at the α-ferrocenylmethyl position has been prepared via a Friedel–Crafts alkylation reaction of (R_c,S_Fc)-PPFA with a variety of 2-indole thioethers. These newly developed ferrocenyl P,S-ligands proved to be efficient in the AgOAc-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with various dipolarophiles, giving cycloadducts with high diastereoselectivities and enantioselectivities (up to 99% ee).     

The effect of acetyl on the electronic communication of carbon-bridged diferrocene

Diferrocenylmethane (1) and 2-acetyl(diferrocenyl)methane (2) were synthesized and characterized by elemental analysis, FT-IR, and NMR. The molecular structures of 1 and 2 were determined using X-ray single crystal diffraction. The effect of acetyl group on electronic communication between two ferrocenyl units of 2 was investigated through cyclic voltammetry and density functional theory calculation. The acetyl did not influence electronic communication between two ferrocenyl units. The key factor that effected electronic communication of carbon-bridged diferrocenyl derivatives was charge density of the bridged carbon.     

Synthesis and Structure of an Enantiomerically Pure C2 Symmetric Ferrocenyl Carbene

The straightforward, high‐yield synthesis and X‐ray structural analysis of the air‐stable planar‐chiral bis(ferrocenyl)carbene 1,3‐bis‐{(1R)‐1‐[(1R)‐1‐(trimethylsilyl)ferrocen‐2‐yl]ethyl}imidazol‐2‐ylidene ( 5 ) is reported. Compound 5 is obtained in four steps from the amine [(1R)‐1‐(dimethylamino)ethyl]ferrocene ( 1 ) upon diastereoselective silylation, methylation, nucleophilic substitution by imidazole, and deprotonation. The X‐ray crystal structure of the free carbene shows the typical conformational features of the 1,2‐disubstituted ferrocenyl units, as found in other ferrocenyl ligands derived from 1 .     

Synthesis and structural characterization of new multiferrocenyl diyne ligands and their cobalt carbonyl complexes

New multiferrocenyl diyne ligands FcC(CH₃)₂Fc′–C≡C–C≡C–Fc [L ₁ ; Fc?=?C₅H₅FeC₅H₄; Fc′?=?C₅H₅Fe(1,3-disubstituted)C₅H₃], FcC(CH₃)₂Fc′–C≡C–C≡C–Fc′C(CH₃)₂Fc (L ₂ ) and their complexes [FcC(CH₃)₂Fc′–C≡C–C≡C–Fc][Co₂(CO)₆] _n [n?=?1, (1); n?=?2, (2)], [FcC(CH₃)₂Fc′–C≡C–C≡C–Fc′C(CH₃)₂Fc][Co₂(CO)₆] _n [n?=?1, (3); n?=?2, (4)] have been synthesized by the coupling reaction of terminal ferrocenylacetylene and the reaction of ligands L₁ and L₂ with Co₂(CO)₈. The composition and molecular structure of the ligands L₁ , L₂ and their cobalt complexes were characterized by element analysis, IR, ¹H(¹³C)NMR and MS. The electrochemical properties of compounds L₁ , L₂ , 1, 2, 3, 4 were studied by cyclic voltammetry(CV). The results of the electrochemical research reveal that all three ferrocenyl groups in L₁ become redox active centers, but there are only two (not four) ferrocenyl redox active centers in L₂ .     

An effective method for the synthesis of monoferrocenylbenzene derivatives

Three new ferrocenylbenzene derivatives, 1-ferrocenyl-2,3,4,5-tetramethylbenzene (1), 1-ferrocenyl-2,4-diphenylbenzene (2), and 1-ferrocenyl-2,4-ditrimethylsilylbenzene (3), were synthesized by cycloaddition of ferrocenylacetylene cobalt cluster with different alkynes and characterized by elemental analysis, FT-IR, NMR, and MS. The molecular structures of 2 and 3 were identified by single-crystal X-ray diffraction. The oxidation potentials of ferrocenyl unit in these compounds were investigated by cyclic voltammetry and theoretical calculations. The results indicated that the electron-donating or electron-withdrawing effect of substituents on the central phenyl was the key factor that influenced the oxidation potential of the ferrocenyl unit.