Synthesis of substituted 1,1′-diaminoferrocenes from cyclo-2-pentene imines

Condensation of anilines and primary aliphatic amines with 3,4-diphenylcyclo-2-pentenone leads to the corresponding diphenylcyclopentene imines in good yields of 72-90%. Deprotonation of these aminocyclopentadiene tautomers and reaction with FeCl₂ leads to the synthesis of the respective 1,1′-diamino-3,3′,4,4′-tetraphenylferrocenes. Yields increase from 33% to 65% with a decrease in the steric bulk of the amine substituent. The observation that a successful conversion requires two equivalents of base is conceived on the basis of the discussed reaction mechanism. The molecular structure of 1,1′-dianilino-3,3′,4,4′-tetraphenylferrocene (3a), which was determined by single crystal X-ray analysis reveals a trans coordination of the two amine moieties with respect to the central Cp-Fe-Cp axis of the ferrocenyl backbone.     

双三烃基锡1,1′-二茂铁二甲酸盐的合成及晶体结构

合成了１３个新的双三烃基锡１,１'－二茂铁二甲酸衍生物,并进行了化合物的波谱表征．Ｃｙ２ＭｅｓｎＯＯＣＦｃＣＯＯＳｎＭｅＣｙ２的Ｘ射线衍射单晶结构测定表明,其结构为单斜晶系,Ｆｄｄ２空间群,晶胞参数:α＝１．８７３ ５(４)ｎｍ,ｂ＝３．５９３ ０(７)ｎｍ,ｃ＝１．１１２ ２(２)ｎｍ;α＝β＝γ＝９０．００(０)°;Ｖ７．４８７(４)ｎｍ３;Ｚ＝８;Ｆ(０００)＝３ ５５２;最终可靠因子Ｒｔ＝０．０４８,Ｒｗ＝０．０５４．为五配位轻微畸变的三角双锥的线性聚合结构化合物．     

A simple method for desymmetrizing 1,1′-ferrocenedicarboxaldehyde

A simple chromatography-free method for desymmetrizing ferrocene is described starting from the readily available dialdehyde. Oxidation of 1,1′-ferrocenedicarboxaldehyde in a water/acetonitrile mixture with KMnO₄ produced 1′-formyl-ferrocenecarboxylic acid. The same reaction carried out in a water/acetone mixture produced 1′-[(E)-3-oxo-but-1-enyl]-ferrocenecarboxylic acid.     

Synthesis of symmetrically and unsymmetrically substituted S,S-dialkyl phosphonodithioates

Herein, we report the synthesis of a range of S,S-dialkyl phosphonodithioates. Symmetrically substituted analogues were readily prepared from the corresponding phosphonic dichlorides in good to moderate yields, while unsymmetrically substituted variants were obtained by a sequential alkylation-deprotection-alkylation strategy.     

1,1-(1-Propene-1,3-diyl)-ferrocene: modified synthesis, crystal structure, and polymerisation behaviour

The dehydro[3](1,1^′)ferrocenophanes, 1,1^′-(1-propene-1,3-diyl)-ferrocene (3a), and 1,1^′-(3-phenyl-1-propene-1,3-diyl)-ferrocene (3b) were synthesised under Shapiro conditions from the tosylhydrazones of the corresponding α-oxo-[3](1,1^′)ferrocenophanes. Electrochemistry shows 3a is oxidised at smilar potential to ferrocene; according 3a can be chemically oxidised using silver trifluoromethanesulfonate. The structure of 3a shows a ring tilt of 11.3°. Attempts to polymerise 3a using the ROMP initiator Mo(CHCMe₂Ph)[N(2,6-ⁱPr₂C₆H₃)][OCMe(CF₃)₂]₂ led to a mixture of insoluble material and a soluble mixture of apparently cyclic oligomers ([3a]_n).     

5,5′-二甲基-2,2′-二茚满-1,1′,3,3′-四酮的合成及结构表征

本文以4-甲基邻苯二甲酸酐为原料, 成功地合成了5,5′-二甲基-2,2′-二茚满-1,1′,3,3′-四酮(2). 通过元素分析、核磁共振、红外光谱及质谱等测试手段, 确定了化合物2的结构与存在形式, 通过ESR测试发现化合物2具有顺磁性.     

Synthesis and properties of 1,1′-bis(diacetylene-group) connected ferrocene-thiophene derivative: a cooperatively functional behavior of diacetylene-group connected constituents

An extended π-electronic conjugation system of 1,1′-bis(diacetylene-group) connected ferrocene-thiophene derivative has been synthesized, with our integrated reaction between the corresponding TMS-protected acetylenes in one-pot. Its electronic properties have been examined, suggesting a cooperatively functional behavior of the diacetylene-group connected constituents.     

1,1′-Bis(oxazolinyl)ferrocene-based palladium catalysts: Synthesis, X-ray structures and applications in Suzuki and Heck coupling reactions

1,1′-Bis(oxazolinyl)ferrocene-based palladium dichloride complexes 2a and 2b were synthesized. X-ray single-crystal diffraction analyses showed that they are of the N,N′-chelating type, and that the coordination mode of 2a, which has an isopropyl group, is of the cis type, whereas that of 2b, which has a tert-butyl group, is the trans one. These two complexes were employed as catalysts for Suzuki and Heck reactions, and showed high catalytic activities in coupling reactions with various aryl halides and counterparts (phenylboronic acid or n-butyl acrylate). Particularly, the catalyst 2a afforded the coupled product of aryl bromide with phenylboronic acid at room temperature.     

Hexanuclear Pt complexes composed of two cyclic triplatinum units connected with 1,4-diphenylene and 1,1′-ferrocenylene spacer

1,4-Bis(dimethylsilyl)benzene reacted with [Pt₃H(PEt₃)₃(μ-PPh₂)₃] at room temperature to yield trinuclear Pt complex [Pt₃(SiMe₂C₆H₄SiMe₂H)(PEt₃)₂(μ-PPh₂)₃] (1a). Heating a solution containing an equimolar mixture of [Pt₃H(PEt₃)₃(μ-PPh₂)₃] and 1a at 60 °C produced a hexanuclear Pt complex [(PEt₃)₂(μ-PPh₂)₃Pt₃(SiMe₂C₆H₄SiMe₂)Pt₃(PEt₃)₂(μ-PPh₂)₃] (2a). Complex 1a was characterized by X-ray crystallography and NMR spectroscopy, while the structure of 2a was determined by X-ray crystallography of single crystals containing 2a and [Pt₃H₂(PEt₃)₂(μ-PPh₂)₄] in 1:1 ratio. [Pt₃(SiMe₂fcSiMe₂H)(PEt₃)₂(μ-PPh₂)₃] (fc = Fe(η⁵-C₅H₄)₂) (1b) and [(PEt₃)₂(μ-PPh₂)₃Pt₃(SiMe₂fcSiMe₂)Pt₃(PEt₃)₂(μ-PPh₂)₃] (2b) were obtained similarly from the reactions of 1,1′-bis(dimethylsilyl)ferrocene with [Pt₃H(PEt₃)₃(μ-PPh₂)₃] and characterized by NMR spectroscopy and elemental analyses.     

Synthesis of 1,2,4,5-tetrazines, symmetrically and unsymmetrically 3,6-disubstituted by N-nucleophiles

6-R-3-(3,5-Dimethylpyrazol-1-yl)-1,2,4,5-tetrazines with aliphatic, cycloaliphatic, and aromatic amines, and also with NH-heterocycles undergo a nucleophilic substitution of the dimethylpyrazole moiety yielding symmetrically and unsymmetrically substituted 1,2,4,5-tetrazines. In the 3,6-diimidazolyl-and 3,6-dibenzotriazolyl derivatives reactions of nucleophilic substitution of the heterocyclic moiety also occur. In some cases an ipsosubstitution of amino, hydrazino, and azido groups is observed.     

The novel transition metal free synthesis of 1,1′-biazulene

Reaction of 1-azulenyl methyl sulfoxide (1) under acidic conditions gave the 1,1′-biazulene derivative 3. Methylmercapt groups of 3 were readily converted to formyl groups by Vilsmeier reaction to afford 3,3′-diformyl-1,1′-biazulene (4), which reacted with pyrrole in the presence of acetic acid to give the parent 1,1′-biazulene (5). Reaction of 5 with pyridine in the presence of Tf₂O gave 3,3′-dihydropyridyl-1,1′-biazulene derivative 6. 3,3′-(4-Pyridyl)-1,1′-biazulene (7) was obtained by the reaction of 3 with KOH in EtOH at room temperature in good yield.     

A 310-helix single turn enforced by crosslinking of lysines with 1,1′-ferrocenedicarboxylic acid

Prior work has shown that covalently linking the side chains of amino acids in the i and i+3 and i and i+4 positions in a peptide will enforce a helical conformation. In this work the ability of an organometallic entity to enforce a helical conformation in a peptide was explored. The tetrapeptide Boc-Lys-Ala-Val-Lys-NHCH₃ was prepared, then reacted with 1,1′-ferrocenedicarboxylic acid chloride. Reaction of the lysine side chain amines with the diacid chloride resulted in a metallacyclicpeptide (1) in which the two lysines are crosslinked via the ferrocene. The solution conformation of the metallacyclicpeptide (1) was studied using CD and NMR spectroscopy. The NMR methods employed were Karplus analysis of coupling constants, chemical shift changes of NH protons and ROESY data. The results show that the metallacyclicpeptide (1) adopts a single turn of the 3₁₀-helix conformation.     

Hydrosilylation and double silylation of carbonyl compounds with 1,1′-bis(dimethylsilyl)ferrocene using nickel- and platinum-catalysts

A series of ferrocene-based organosilicon compounds have been prepared via hydrosilylation or double silylation of carbonyl compounds with 1,1′-bis(dimethylsilyl)ferrocene using (C₂H₄)Pt(PPh₃)₂ or Ni(PEt₃)₄ catalysts. In general, while the platinum catalyst (C₂H₄)Pt(PPh₃)₂ preferentially produced cyclic double-silylated products, the Ni(PEt₃)₄ catalyst led to the hydrosilylated ferrocene products from aldehydes or ketones.     

Copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate) catalyzed synthesis of N-substituted ferrocenes

An efficient catalytic protocol for the Ulmann-type coupling reaction of both bromo and iodoferrocene with heterocyclic amines using a stable and well defined copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate) complex has been developed. The protocol was applicable for the synthesis of wide variety of N-substituted ferrocenes and the desired products were obtained in good to excellent yields.     

Oxidative coupling of 2-substituted 1,2-dihydro-1-naphthols using Jones reagent: a simple entry into 3,3′-disubstituted 1,1′-binaphthyl-4,4′-diols

2-Substituted 1,2-dihydro-1-naphthols underwent regioselective oxidative dimerization, when treated with Jones reagent, to furnish 3,3′-disubstituted 1,1′-binaphthyl-4,4′-diols. A series of symmetrical binaphthols were prepared and it was shown that the coupling reaction proceeds via the sequential oxidation of 2-substituted 1,2-dihydro-1-naphthols to 2-substituted 1-naphthols, which oxidatively dehydrodimerized.     

功能性二茂铁单、双乙基咪唑的合成

以单、双乙酰基二茂铁为原料,经还原和脱水反应,高效地合成了单、双齿功能性配体--二茂铁乙基咪唑和二茂铁双乙基咪唑,其结构经1H NMR,IR,MS和元素分析表征.     

Synthesis and characterization of 6,6″′-bis(anthracen-9-yl)-2,2′;6′,2″;6″,2″′-quaterpyridine

New bianthracene-quaterpyridine ligand 6,6″′-bis(anthracen-9-yl)-2,2′;6′,2″;6″,2″′-quaterpyridine L has been obtained in a multistep synthesis using Suzuki–Miyaura and Stille-type coupling reactions. The dianthracene ligand L has four nitrogen-donor atoms and can form different supramolecular architectures with transition metal ions. Ligand L and intermediate compounds have been characterized by spectroscopic methods and elemental analyses. 2-(Anthracen-9-yl)-6-bromopyridine and 6-(anthracen-9-yl)-6′-bromo-2,2′-bipyridine have been also characterized by X-ray crystallography.     

Synthesis of a new bidentate ferrocenyl N-heterocyclic carbene ligand precursor and the palladium (II) complex trans-[PdCl2(CfcC)], where (CfcC) = 1,1′-di-tert-butyl-3,3′-(1,1′-dimethyleneferrocenyl)-diimidazol-2-ylidene

A new ferrocenyl-N-heterocyclic carbene ligand precursor 1,1′-bis[(1-tert-butylimidazolium)-3-methyl]ferrocene dichloride has been synthesised and structurally characterised. The imidazolium salt was readily deprotonated in situ with KN(SiMe₃)₂ and reacted with [PdCl₂ (cod)] to afford the structurally characterised palladium (II) complex trans-[PdCl₂(C^∧fc^∧C)], where (cod) = 1,5-cyclooctadiene and (C^∧fc^∧C) = 1,1′-di-tert-butyl-3,3′-(1,1′-dimethyleneferrocenyl)-diimidazol-2-ylidene.     

Synthesis and reactivity of ruthenium complexes with 1,1′-dithiolate ligands

Reactions of [Ru(PPh₃)₃Cl₂] with ROCS₂K in THF at room temperature and at reflux gave the kinetic products trans-[Ru(PPh₃)₂(S₂COR)₂] (R = ⁿPr 1, ⁱPr 2) and the thermodynamic products cis-[Ru(PPh₃)₂(S₂COR)₂] (R = ⁿPr 3, ⁱPr 4), respectively. Treatment of [RuHCl(CO)(PPh₃)₃] with ROCS₂K in THF afforded [RuH(CO)-(S₂COR)(PPh₃)₂] (R = ⁿPr 5, ⁱPr 6) as the sole isolable products. Reaction of [RuCl₂(PPh₃)₃] with tetramethylthiuram disulfide [Me₂NCS₂]₂ gave a Ru(III) dithiocarbamate complex, [Ru(PPh₃)₂(S₂CNMe₂)Cl₂] (7). This reaction involved oxidation of ruthenium(II) to ruthenium(III) by the disulfide group in [Me₂NCS₂]₂. Treatment of 7 with 1 equiv. of [M(MeCN)₄][ClO₄] (M = Cu, Ag) gave the stable cationic ruthenium(III)-alkyl complexes [Ru{C(NMe₂)QC(NMe₂)S}(S₂CNMe₂)(PPh₃)₂][ClO₄] (Q = O 8, S 9) with ruthenium-carbon bonds. The crystal structures of complexes 1, 2, 4·CH₂Cl₂, 6, 7·2CH₂Cl₂, 8, and 9·2CH₂Cl₂ have been determined by single-crystal X-ray diffraction. The ruthenium atom in each of the above complexes adopts a pseudo-octahedral geometry in an electron-rich sulfur coordination environment. The 1,1′-dithiolate ligands bind to ruthenium with bite S-Ru-S angles in the range of 70.14(4)-71.62(4)°. In 4·CH₂Cl₂, the P-Ru-P angle for the mutually cis PPh₃ ligands is 103.13(3)°, the P-Ru-P angles for other complexes with mutually trans PPh₃ ligands are in the range of 169.41(4)-180.00(6)°. The alkylcarbamate [C(NMe₂)QC(NMe₂)S]⁻ (Q = O, S) ligands in 8 and 9 are planar and bind to the ruthenium centers via the sulfur and carbon atoms from the CS and NC double bonds, respectively. The Ru-C bond lengths are 1.975(5) and 2.018(3) Å for 8 and 9·2CH₂Cl₂, respectively, which are typical for ruthenium(III)-alkyl complexes. Spectroscopic properties along with electrochemistry of all complexes are also reported in the paper.     

Synthesis and pyrolysis of silicon and tin containing poly(2,2′-dioxy-1,1′-biphenoxy-phosphazenes)

The polyphosphazene {[NP(O₂C₁₂H₈)]_0.5[NP(OC₆H₄Br)₂]_0.5}_n (1) [(O₂C₁₂H₈) = 2,2′-dioxy-1,1′-biphenyl] that, as an strictly alternating copolymer, can be considered nearly as the homopolymer [NP(O₂C₁₂H₈)NP(OC₆H₄Br)₂]_n, was reacted first with ^tBuLi in THF at −78 °C to give the intermediate [NP(O₂C₁₂H₈)NP(OC₆H₄Li)₂]_n (2) and subsequently with the chlorosilanes SiMe₃Cl and SiMe₂(C₆H₅)Cl or with the chlorostannane SnMe₃Cl, to obtain the new polyphosphazenes {(NP[O₂C₁₂H₈])_0.5[NP(OC₆H₄SiMe₃)₂]_0.5−x[NP(OC₆H₅)(OC₆H₄SiMe₃)]_x}_n (3a) (x = 0.15-0.5), {(NP[O₂C₁₂H₈])_0.5[N(POC₆H₄SiMe₂Ph)₂]_0.2[NP(OC₆H₅)(OC₆H₄SiMe₂Ph)]_0.3}_n (3b), and {(NP[O₂C₁₂H₈])_0.5[NP(OC₆H₅)(OC₆H₄SnMe₃)]_0.5}_n (4), having a very regular distribution of the silicon or tin organometallic sites along the chains. The pyrolysis of the polymers in air at 800 °C gave microcrystalline residues (characterized by IR, XRD, SEM and TEM-EDXA) consisting on phases of SiO₂ · P₂O₅ · P₂O_7.9 · SiP₂O₇, or, in the case of the tin derivative, almost pure SnP₂O₇. The results indicate that, while part of the Si content is lost during the pyrolysis, almost all the tin in the original polymer was incorporated to the final residue.