Products of hydrolysis of (ferrocenylmethyl)trimethylammonium iodide: Synthesis of hydroxymethylferrocene and bis(ferrocenylmethyl) ether

The attempted coupling of (ferrocenylmethyl)trimethylammonium iodide (1) with 1,4,7-(triformyl)-1,4,7,10-tetraazacyclododecane (2) in water led to the formation of the expected compound 1-(ferrocenemethyl)-4,7,10-(triformyl)-1,4,7,10-tetraazacyclododecane (3). In addition, hydrolysis of the ferrocenyl precursor 1 led to the formation of two other known compounds, hydroxymethylferrocene (4) and bis(ferrocenylmethyl) ether (5). An X-ray crystal structure determination of 4 revealed the presence of H-bonding between the hydroxyl groups of one molecule of 4 and the oxygen atom of an adjacent molecule resulting in a left-handed helical chain of molecules lying along the b-axis direction. The O?O distances are significantly shorter than those found in previously reported structures of hydroxymethylferrocene derivatives indicative of moderate strength H-bonding interactions. In the structure of 5, the orientation of the ferrocenyl groups are staggered relative to a vector comprising the two carbons of the C-O-C linker.     

Synthesis, structures and spectroelectrochemistry of methyl-substituted bis(η-indenyl)iron(II) complexes

Several new methyl-substituted indenyl ferrocenes were prepared by metathesis reactions of the indenide (generated from the appropriate indene with BuLi) with ferrous chloride. The indenides used to prepare new ferrocenes were: 2-methyl-, 1,2-dimethyl-, 4,7-dimethyl-, 1,4,7-trimethyl-, and 1,3,4,7-tetramethyl-indenide. These indenyl ferrocenes, along with those prepared from indenide, 1-methylindenide, and 1,3-dimethylindenide, were then characterized by ¹H and ¹³C NMR, UV/visible spectroscopy, cyclic voltammetry and mass spectrometry. The cyclic voltammetry showed an additive relationship between oxidation potential and the number of methyl groups which is also position-dependent, whereas the UV/visible spectra showed two absorptions essentially unaffected by methyl substitution. Additionally, bis(2-methylindenyl)iron(II) and bis(4,7-dimethylindenyl)iron(II) were characterized by X-ray crystallography.     

Direct reductive amination of carbonyl compounds using bis(triphenylphosphine) copper(I) tetrahydroborate

A direct reductive amination protocol for aldehydes/ketones using bis(triphenylphosphine) copper(I) tetrahydroborate as a novel reducing agent in the presence of sulfamic acid has been developed. The reagent chemoselectively reduces the imine moiety and does not affect other reducible functionalities such as chloro, nitro, cyano and methoxy.     

One-pot reductive amination of aldehydes catalyzed by a hydrio-iridium(III) complex in aqueous medium

A combination of sodium tetrakis[3,5-di(trifluoromethyl)phenyl]borate [NaBAr^F₄] and hydrio-iridium(III) complex efficiently catalyzed the one-pot reductive amination of aldehydes with various amines and ammonia in water under mild conditions in good to excellent yields.     

Synthesis,characterization, and application of silica supported ionic liquid as catalyst for reductive amination of cyclohexanone with formic acid and triethyl amine as hydrogen source

A silica supported ionic liquid was synthesized and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption-desorption, and thermogravimetric analysis. All these techniques, especially SEM results indicated the presence of well-defined spherical particles having diameters larger than the pristine silica particles, confirming the successful immobilization of the ionic liquid. The prepared silica supported ionic liquid was used in the reductive amination of cyclohexanone under different conditions with different azeo-tropic mixtures of formic acid and triethyl amine as a hydrogen source. The catalyst showed effi-cient catalytic performance and excellent yields of N-cyclohexyl amine derivatives in the range of 58%to 84%at 30 °C. After completion of the reaction, the catalyst was easily recovered by simple filtration and reused for another five cycles without any significant impact on product yields. The obtained catalytic performance indicates that the present catalyst is green, very active, and reusable for the reductive amination of cyclohexanone.     

Synthesis, structural characterisation and biological activity of novel N-(ferrocenylmethyl)benzene-carboxamide derivatives

A series of N-(ferrocenylmethyl)benzene-carboxamide derivatives (4a-f) have been synthesised by coupling ferrocenylmethyl amine 3 with benzoic acid and various substituted fluorobenzoic acids using the standard 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt) protocol. All compounds were fully characterised using a combination of ¹H NMR, ¹³C NMR, ¹⁹F NMR, DEPT-135, ¹H-¹H COSY and ¹H-¹³C COSY (HMQC) spectroscopy and electrospray ionisation mass spectrometry (ESI-MS). The compounds 4a, 4d, 4e and 4f exhibited cytotoxic effects on the MDA-MB-435-S-F breast cancer cell line. Single crystal X-ray crystallographic data for 4d is also presented.     

Synthesis and properties of 5-ferrocenyl-1H-pyrazole-3-carbaldehydes

New ferrocene derivatives - ethyl esters of 1-aryl-5-ferrocenyl-1H-pyrazole-3-carboxylic acids were synthesized. The corresponding aldehydes were obtained from acid esters in two steps. The reductive amination reaction of 5-ferrocenyl-1-phenyl-1H-pyrazole-3-carbaldehyde was studied. Several of these compounds were investigated by cyclic voltammetry. All of them exhibited a reversible one-electron oxidation-reduction wave owing to the ferrocene-ferricinium redox couple with a positive shift (0.51-0.69 V) compared with that of ferrocene (0.46 V). The X-ray crystal structure of the ethyl ether 1-(3-chloro-2-fluorophenyl)-5-ferrocenyl-1H-pyrazole-3-carboxylic acid is also presented.     

Synthesis,spectroscopic characterization,and X-ray crystal structure of tris(trimethylsilyl)cyanurate

Tris(trimethylsilyl)cyanurate, C₁₂H₂₇N₃O₃Si₃ (1), has been synthesized and characterized by elemental analysis, IR, Raman, ¹³C and ²⁹Si NMR, and thermogravimetric methods. The molecular and crystal structure has been determined by single crystal X-ray diffraction. This compound crystallized in space group P6₃/m (176), Z = 2 with a = 11.017(2), b = 11.017(2), c = 9.676(3) Å; α = 90°, β = 90°, γ = 120°. The geometry of the molecule is compared with tris(trimethylsilyl)cyamelurate.     

Synthesis,characterization and crystal structures of oxidovanadium(V) hydrazone complexes with antibacterial activity

Abstract

Reaction of VO(acac)₂ with the hydrazone ligands N’-(2-hydroxybenzylidene)-3methylbenzohydrazide (H₂L¹) and N’-(2-hydroxybenzylidene)-3-methyl-4-nitrobenzohydrazide (H₂L²) afforded two oxidovanadium(V) complexes, [VOL¹(OMe)(MeOH)] (1) and [VOL²(OEt)(EtOH)] (2), respectively. The complexes have been characterized by elemental analyses, IR, UV-Vis, molar conductivity and X-ray single crystal diffraction techniques. The hydrazone ligands coordinate to the V ions through the phenolate oxygen, imino nitrogen and enolate oxygen atoms. The V ions in both complexes are in octahedral coordination, with the three donor atoms of the hydrazone ligands, and with the other three sites furnished by one methanol or ethanol oxygen atom, one deprotonated methanol or ethanol oxygen atom, and one oxo oxygen. The complexes were assayed for their antibacterial activity on the bacteria B. subtilis, E. coli, P. putida and S. aureus.     

Stereochemistry of the products of reductive amination of 2,6-bis[(2-oxocyclohexyl)methyl]cyclohexanone, an alicyclic 1,5,9-triketone

The reductive amination of alicyclic 1,5,9-triketone—2,6-bis[(2-oxocyclohexyl)methyl]cyclohexanone—has been studied under Leuckart reaction conditions and in the presence of NaBH₃CN. A mixture of diastereomers of quinolizidine structure (2,3,5,6-bistetramethylenehexahydrojulolidine) is obtained. The stereochemistry of seven isomers is determined by the study of their NMR spectra using 2D NMR experiments (¹H-¹H COSY, HSQC, and HMBC).     

One-pot reductive amination of aldehydes and ketones with α-picoline-borane in methanol, in water, and in neat conditions

A one-pot reductive amination of aldehydes and ketones with amines using α-picoline-borane as a reducing agent is described. The reaction has been carried out in MeOH, in H₂O, and in neat conditions in the presence of small amounts of AcOH. This is a highly efficient and mild procedure that is applicable for a wide variety of substrates. In particular, this is the first successful demonstration that this type of reaction can be carried out in water and in neat conditions.     

Synthesis of enantiopure β-amino amides via a practical reductive amination of the corresponding β-keto amides

A convenient and efficient reductive amination for the preparation of chiral β-amino amides is developed utilizing microwave heating. A variety of chiral β-keto amides react with ammonium acetate and sodium cyanoborohydride to afford the desired functionalized amines in good yields. This improved procedure takes advantage of microwave heating to significantly accelerate the reaction and offers a convenient and effective method to access some interesting molecules containing primary amine functionalities.     

Synthesis,spectral, thermal and BVS investigations on ZnS4N^N/N coordination environment: Single crystal X-ray structures of bis(dibenzyldithiocarbamato)(N^N)Zinc(II) complexes (N^N = 1,10-phenanthroline,tetramethylethylenediamine and 4,4′-bipyridine)

The current paper describes the synthesis and spectral investigations on the adducts of [Zn(dbzdtc)₂] (1) with 1,10-phen (2), tmed (3), 2,2′-bipy (4) and 4,4′-bipy (5) (where, dbzdtc = dibenzyldithiocarbamate anion, 1,10-phen = 1,10-phenanthroline, tmed = tetramethylethylenediamine, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridne) and single crystal X-ray structures of [Zn(dbzdtc)₂(1,10-phen)] (2) and [Zn(dbzdtc)₂(tmed)] (3) and [Zn(dbzdtc)₂(4,4′-bipy)] (5). ¹H and ¹³C NMR spectra of 1,10-phen, tmed, 2,2′-bipy and 4,4′-bipy adducts were recorded. ¹H NMR spectra of the complexes show the drift of electrons from the nitrogen of the substituents forcing a high electron density towards sulfur via the thioureide π-system. In the ¹³C NMR spectra, the most important thioureide (N¹³CS₂) carbon signals are observed in the region: 206–210 ppm. Fluorescence spectra of complexes (2) and (4) show intense fluorescence due to the presence of rigid conjugate systems such as 1,10-phenanthroline and 2,2′-bipyridine. The observed fluorescence maxima for complexes with an MS₄N₂ chromophore in the visible region are assigned to the metal-to-ligand charge transfer (MLCT) processes. Single crystal X-ray structural analysis of (2) and (3) showed that the zinc atom is in a distorted octahedral environment. Bond Valence Sum was found to be equivalent to 1.865 for (2), 1.681 for (3) supporting the correctness of the determined structure. BVS of (3) deviates from the formal oxidation number of zinc due to the non-aromatic, sterically hindering tetramethyl bonding end of tmed. Thermal studies on the compounds show the formation of Zn(NCS)₂ as an intermediate during the decay.     

Synthesis,crystal structures and spectroscopic properties of dichloroethylphenyltin(IV) and its phenanthroline adduct

The reaction of dichloroethylphenyltin(IV), Ph(Et)SnCl₂, with phenanthroline monohydrate (phen·H₂O) in chloroform, in 1:1 mole ratio, afforded [Ph(Et)SnCl₂(phen)]. The crystal structures of dichloroethylphenyltin(IV) and its phenanthroline adduct were studied by X‐ray diffraction. In Ph(Et)SnCl₂ the tin atom is in a distorted tetrahedral environment, the distortion probably being imposed by weak intermolecular Sn· · ·Cl interactions. In [Ph(Et)SnCl₂(phen)] the tin atom is in an octahedral trans‐C₂, cis‐Cl₂, N₂ environment and weak intermolecular C–H· · ·Cl interactions connect the molecules throughout the lattice. Spectroscopic studies in solution (¹H, ¹³C and ¹¹⁹Sn NMR) were also carried out; the ¹H and ¹³C NMR data in dimethylsulfoxide suggest that [Ph(Et)SnCl₂(phen)] remains at least partially undissociated in this solvent. Copyright © 2003 John Wiley & Sons, Ltd.     

Synthesis, crystal structures, electrochemical studies and anti-tumor activities of three polynuclear organotin(IV) carboxylates containing ferrocenyl moiety

A novel ferrocene-containing ligand 3-trifluoromethyl-5-ferrocenyl -pyrazol-1-yl-acetic acid (LCOOH) and three organotin(IV) carboxylate derivatives [Ph₄Sn₂O(OCH₃)(OOCL)]₂(1), [BuSnO(OOCL)]₆(2) and [Bu₄Sn₂O(OOCL₂)₂] (3) have been synthesized and structurally characterized by means of FT-IR, elemental analysis, ¹H NMR, ¹¹⁹Sn NMR, X-ray crystallography and cyclic voltammetry. Both complexes 1 and 3 are centrosymmetric with ladder framework. Complex 2 is a hexanuclear one with drum structure. Furthermore, their anti-tumor activities were also evaluated, using HepG2 human hepatocellular liver carcinoma cells, A549 human lung carcinoma cells and B16-F10 melanoma cells. Complex 1 displayed the best cytotoxicity and can be pointed out as a promising substrate to be subject of further investigations.     

Synthesis,structure, and characterization of Cu4S10(4-methylpyridine)4

The title compound, Cu₄S₁₀(4-methylpyridine)₄ · 4-methylpyridine was prepared by three different reactions: the oxidation of copper power by sulfur and the reaction of copper (I) sulfide (or CuBr-SMe₂) with cues sulfur, both in the coordinating solvent, 4-methylpyridine. Red crystals of the compound obtained by layering with hexans were subjected to single crystal X-ray diffraction. The structure was refined toR=0.026 and R _w =0.036 in a space groupP1bar (No. 2), withZ=2,a=13.983 (2) A,b=15.384( 2) Å,c=9.660 (1) Å, = 93.87 (1)°,=93.38 ==(1)°,V=2037.9 (9) ų. The commpound has approximate S₄ symmetry and consists of two pentasuffide chains linking four Cu(I) ions, each with a coordinating 2-methylpyridine. The infrared spectrum was dominated by absorption due to coodinated 4-methylpyridine with several low-energy peaks attributable to S-S stretches, which were also observed by Raman spectroscopy. A featureless electronic absorption spectrum yielded a single peak in the mar ultraviolet upon computer enhancement (=334 nm, = 10,000), most likely an intraligand transition. Cyclic voltammetry indicates that the polysulfide complex undergoes irreversible oxidation and reduction at +0.04 and –0.34 V vs. SCR respectively, at NS K in 4-methylpyridine when swept at 20 mV/sec. The electrochemical behavior was unvaried even at sweep rates as high as 100 V/sec.     

三维骨架结构有机锡化合物－－1，5－戊二酸双（三苯基锡）酯的合成、谱学表征和晶体结构

用三苯基氯化锡与1，5－戊二酸二钠以2：1摩尔比反应，合成了1，5－戊二酸 双（三苯基锡）酯，并进行了红外光谱、核磁共振氢谱及质谱表征。X射线单晶衍 射表明，该化合物属正交晶系，空间群C222（1），晶胞参数：a=1.5075(5)nm， b=4.8021(17)nm,c=2.8944(9)nm,α＝90°,β=90°，γ＝90°，V＝20.953(12) nm^3，Z=8,Dc=1.316g/cm^3，μ＝1.226mm^-1,F(000)=8280,R1=0.0546,wR2=0. 1182。晶体结构中存在5种化学环境不同的三角双锥构型的锡原子，由于配体中两 个羧基在不同方向的交联作用，使化合物呈现三维骨架结构，并且在骨架结构中存 在沿a轴和c轴方向伸展的规则的大环直孔道。     

Synthesis,crystal structure and stereochemical non-rigidity of (O-Sn)-bischelated bis(lactamomethyl)dichlorostannanes

Previously unknown (0-Sn)-bischelated bis(lactamomethyl)dichlorostannanes have been synthesized by a direct method from metallic tin and N-chloromethyllactams. According to X-ray structural analysis data, in the solid state in these compounds the tin atom is hexacoordinated and has an octahedral configuration with the two carbon atoms in the transposition, and both coordinating oxygen atoms and the two halogen atoms in thecis-position. A comparison to Ge-analogs indicates that the replacement of the central atom of the coordination unit MCl₂O₂C₂ has inconsistent effects on the parameters of the latter. According to¹H and¹¹⁹1 Sn NMR data, the hexacoordination of tin and the geometry of the coordination unit are also retained in solution at low temperatures. At higher temperatures a dynamic process takes place resulting in isochronisms of the protons signals of the NCH₂Sn groups. Quantum-chemical calculations of isomeric bis(lactamomethyl)dichlorostannanes by MNDO and MNDO/PM3 methods have been discussed.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp 2768–2779, November, 1996.     

NMR and fluorescence spectral studies on bisdithiocarbamates of divalent Zn,Cd and their nitrogenous adducts: Single crystal X-ray structure of (1,10-phenanthroline)bis(4-methylpiperazinecarbodithioato) zinc(II)

The current paper describes the synthesis and characterization of the following adducts: [Zn(4-mpzdtc)₂(1,10-phen)] · H₂O (1), [Zn(4-mpzdtc)₂(2,2′-bipy)] (2), [Cd(4-mpzdtc)₂(1,10-phen)] (3), [Cd(4-mpzdtc)₂(2,2′-bipy)] (4), [Zn(padtc)₂(1,10-phen)] (5) and [Cd(padtc)₂(1,10-phen)] (6) (where, 4-mpzdtc = 4-methylpiperazinecarbodithioate anion, padtc = N,N′-(iminodiethylene)bisphthalimide dithiocarbamate anion, 1,10-phen = 1,10-phenanthroline and 2,2′-bipy = 2,2′-bipyridine). All the synthesized complexes were characterized by UV–Vis, IR, NMR, (¹H and ¹³C) and fluorescence spectra. A single crystal X-ray structural analysis was carried out for complex 1. IR spectra of the complexes show the contribution of the thioureide form to the structures. The observed deshielding of the α-protons for 1–6 in the ¹H NMR spectra is attributed to the drift of electrons from the nitrogen of the NR₂ groups, forcing a high electron density towards sulfur via the thioureide π-system. In the ¹³C NMR spectra, the most important thioureide (N¹³CS₂) carbon signals are observed in the region 206–208 ppm. Fluorescence spectra of complexes 5 and 6 show intense fluorescence due to the presence of rigid conjugated systems such as phthalimide and 1,10-phenanthroline. The observed fluorescence maxima for complexes with a MS₄N₂ chromophore in the visible region are assigned to the metal-to-ligand charge transfer (MLCT) processes. Single crystal X-ray structural analysis of 1 showed that the zinc atom is in a distorted octahedral environment with a MS₄N₂ chromophore. VBS equivalent to 1.81 supports the correctness of the determined structure. The piperazine ring in the dithiocarbamate fragment is in the normal chair conformation.     

Intramolecular reductive amination strategy to the synthesis of (R)-N-Boc-2-hydroxymethylmorpholine, N-(3,4-dichlorobenzyl)(R)-2-hydroxymethylmorpholine, and (R)-2-benzylmorpholine

A concise high yielding enantioselective synthesis of (R)-N-Boc-2-hydroxymethylmorpholine, N-(3,4-dichlorobenzyl)(R)-2-hydroxymethylmorpholine, and (R)-benzylmorpholine has been achieved by employing proline-catalyzed asymmetric α-aminooxylation of aldehyde and palladium-catalyzed intramolecular reductive amination of azido aldehyde as the key steps.