Synthesis and reactivity of bis(cycloamidinium-2-yl)alkane bromide tribromides,brominating agents and tectons for molecular engineering

Bis(cycloamidine-2-yl)alkanes easily form bromide tribromide salts in the reduction-oxidation processes with bromine. Bis(tetrahydroimidazolium-2-yl)ethane and bis(hexahydropyrimidinium-2-yl)-ethane bromide tribromides are such new convenient brominating agents for aromatic amides in chemo- and regioselective electrophilic substitutions and α-bromination reactions. Correspondence: Katarzyna Ostrowska, Department of Organic Chemistry, Jagiellonian University, R. Ingardena 3, PL-30060 Kraków, Poland.     

Bridged bis(amidinate) lanthanide complexes: Synthesis,molecular structure and reactivity

The yttrium chloride with the bridged bis(amidinate) L (L = Me₃SiNC(Ph)N(CH₂)₃NC(Ph)NSiMe₃) LYCl(DME) (2) was synthesized and structurally characterized. Treatment of LLnCl(sol)_x (Ln = Yb, sol = THF, x = 2 1; Ln = Y, sol = DME, x = 1 2) with the dilithium salt Li₂L(THF)_0.5 afforded the novel bimetallic lanthanide complexes supported by three ligands, Ln₂(μ₂-L)₃ · DME (Ln = Yb 3, Y 4; DME = dimethylether), instead of the designed complex LLn(μ₂-L)LnL via the ligand redistribution reaction. Complexes 3 and 4 were fully characterized including X-ray analysis and ¹H NMR spectrum for 4. Reaction of LnCl₃ (Ln = Yb, Y) with 2 equiv. of Li₂L(THF)_0.5 gave the anionic complexes [Li(DME)₃][L₂Ln] (Ln = Yb 5, Y 6), which were confirmed by a crystal structure determination. The further study indicated that complexes 3 and 4 can also be synthesized by reaction of LnCl₃ (Ln = Yb, Y) with 1.5 equiv. of Li₂L(THF)_0.5 or reaction of 1 and 2 with anionic complexes 5 and 6. Complexes 3, 4, 5 and 6 were found to be high active catalysts for ring-opening polymerization of ε-caprolactone (CL).     

Synthesis of D-Glucos-2-yl Sucros-2-yl Phosphate (Agrocinopin C) and bis(D-glucos-2-yl) Phosphate (Agrocinopin D)

Abstract

The synthesis of a substance with the revised structure proposed for agrocinopin C, D-glucos-2-yl sucros-2-yl phosphate, via the hydrogen-phosphonate approach to phosphodiesters is presented. Agrocinopin D, related to agrocinopin C by the lack of the fructofuranosyl part of the sucrose moiety, is synthesized via direct formation of hydrogen-phosphonate diesters from appropriately protected monosaccharides and phosphonic acid.     

Synthesis and reactivity of bis(3,5-dimethylpyrazol-1-yl)ethane tetracarbonylmolybdenum and tungsten X-ray crystal structureof bis(3,5-dimethylpyrazol-1-yl)ethane tetracarbonyltungsten

Bis(3,5-dimethylpyrazol-1-yl)ethane tetracarbonylmolybdenum (1a) and tungsten (1b) have been synthesized by the direct reaction of bis(3,5-dimethylpyrazolyl)ethane (bmpze) with M(CO)₆ (M = Mo or W). The molecular structure (1b), determined by x-ray crystallography, showed the seven-membered ring W–N–N–C–C–N–N to be in the boat conformation. Upon treatment with RSnCl3 (R=Ph or Cl) in CH₂Cl₂ at room temperature, complexes (1a) and (1b) gave the seven-coordinate oxidative-addition products [(bmpze)M(CO)₃(SnCl₂R)Cl] [M = Mo, R = Ph, (2a); M = W, R=Ph, (2b); M = Mo, R = Cl, (2c); M = W, R = Cl, (2d)]. When complexes (1b) and (2b) were heated under reflux with 1,2-bis(diphenylphosphino)ethane (dppe), the ligand, bmpze, in these complexes was easily removed. The novel compounds were characterized by ¹H-n.m.r., i.r. and elemental analysis.     

Ultra-high pressure direct syntheses of bis(imidazolium-3-yl)alkane dichlorides

The ultra-high pressure Menshutkin reaction of N-substituted imidazoles and α,ω-dichloroalkanes provides access to a wide variety of bis(imidazoliumyl)alkane dichlorides in an efficient, one-pot process. Although the substitution reactions of dichloromethane at ambient pressure can be exceedingly slow, at 1.9 GPa, syntheses are usually quantitative in under 24 h. Reactions involving congested imidazole starting materials, that otherwise terminate after formation of the mono-imidazolium salt, are driven to the bis-imidazolium salt at 1.9 GPa. The rates of reaction increase with α,ω-dichloroalkane chain length, decrease with increasing bulk and imidazole N-substituent length, and the reactions of the more hindered imidazoles are more sensitive to the pressure-rate enhancement.     

Synthesis and structure of a complex of copper(II) bromide with bis(benzotriazol-1-yl)methane

The preparation technique of a complex of copper(II) bromide with bis(benzotriazol-1-yl)methane (L), (Cu₂L₂Br₄)_n, is developed. The compound is studied by single crystal and powder X-ray diffraction and static magnetic susceptibility techniques. According to single crystal XRD data, the complex has a layered structure determined by bidentate bridging coordination of L with N(3) and N(3′) atoms to copper(II). The elementary unit of {Cu₂(μ-Br)₂Br₂} polymer has a binuclear structure. The coordination polyhedron is a trigonal pyramid, and the coordination core is CuN₂Br₃. The temperature dependence of effective magnetic moment is studied within an interval of 2–300 K. The nature of the μ_eff(T) dependence indicates that antiferromagnetic exchange interactions dominate in exchange clusters of the complex with an even number of paramagnetic centers. Original Russian Text Copyright ? 2007 by E. V. Lider, A. S. Potapov, E. V. Peresypkina, A. I. Smolentsev, V. N. Ikorskii, A. I. Khlebnikov, and L. G. Lavrenova __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No.3, pp.543–547, May–June, 2007.     

Synthesis, structure, and reactivity of ruthenium carboxylato and 2-oxocarboxylato complexes bearing the bis(3,5-dimethylpyrazol-1-yl)acetato ligand

A series of ruthenium(II) acetonitrile, pyridine (py), carbonyl, SO2, and nitrosyl complexes [Ru(bdmpza)(O2CR)(L)(PPh3)] (L = NCMe, py, CO, SO2) and [Ru(bdmpza)(O2CR)(L)(PPh3)]BF4 (L = NO) containing the bis(3,5-dimethylpyrazol-1-yl)acetato (bdmpza) ligand, a N,N,O heteroscorpionate ligand, have been prepared. Starting from ruthenium chlorido, carboxylato, or 2-oxocarboxylato complexes, a variety of acetonitrile complexes [Ru(bdmpza)Cl(NCMe)(PPh3)] (4) and [Ru(bdmpza)(O2CR)(NCMe)(PPh3)] (R = Me (5a), R = Ph (5b)), as well as the pyridine complexes [Ru(bdmpza)Cl(PPh3)(py)] (6) and [Ru(bdmpza)(O2CR)(PPh3)(py)] (R = Me (7a), R = Ph (7b), R = (CO)Me (8a), R = (CO)Et (8b), R = (CO)Ph) (8c)), have been synthesized. Treatment of various carboxylato complexes [Ru(bdmpza)(O2CR)(PPh3)2] (R = Me (2a), Ph (2b)) with CO afforded carbonyl complexes [Ru(bdmpza)(O2CR)(CO)(PPh3)] (9a, 9b). In the same way, the corresponding sulfur dioxide complexes [Ru(bdmpza)(O2CMe)(PPh3)(SO2)] (10a) and [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b) were formed in a reaction of the carboxylato complexes with gaseous SO2. None of the 2-oxocarboxylato complexes [Ru(bdmpza)(O2C(CO)R)(PPh3)2] (R = Me (3a), Et (3b), Ph (3c)) showed any reactivity toward CO or SO2, whereas the nitrosyl complex cations [Ru(bdmpza)(O2CMe)(NO)(PPh3)](+) (11) and [Ru(bdmpza)(O2C(CO)Ph)(NO)(PPh3)](+) (12) were formed in a reaction of the acetato 2a or the benzoylformato complex 3c with an excess of nitric oxide. Similar cationic carboxylato nitrosyl complexes [Ru(bdmpza)(O2CR)(NO)(PPh3)]BF4 (R = Me (13a), R = Ph (13b)) and 2-oxocarboxylato nitrosyl complexes [Ru(bdmpza)(O2C(CO)R)(NO)(PPh3)]BF4 (R = Me (14a), R = Et (14b), R = Ph (14c)) are also accessible via a reaction with NO[BF4]. X-ray crystal structures of the chlorido acetonitrile complex [Ru(bdmpza)Cl(NCMe)(PPh3)] (4), the pyridine complexes [Ru(bdmpza)(O2CMe)(PPh3)(py)] (7a) and [Ru(bdmpza)(O2CC(O)Et)(PPh3)(py)] (8b), the carbonyl complex [Ru(bdmpza)(O2CPh)(CO)(PPh3)] (9b), the sulfur dioxide complex [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b), as well as the nitrosyl complex [Ru(bdmpza)(O2C(CO)Me)(NO)(PPh3)]BF4 (14a), are reported. The molecular structure of the sulfur dioxide complex [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b) revealed a rather unusual intramolecular SO2-O2CPh Lewis acid-base adduct.     

Synthesis and properties of bis(heteroazulen-3-yl)methyl cations and bis(heteroazulen-3-yl)ketones

The synthesis and properties of a novel type of bis(heteroazulen-3-yl)methyl cations, bis(2-oxo-2H-cyclohepta[b]furan-3-yl)methyl cation salt and nitrogen analogues, (9a-c·PF₆⁻) and (9a-c·BF₄⁻), as well as bis(heteroazulen-3-yl)ketones (12a-d) are studied. The synthetic method was based on a TFA-catalyzed electrophilic aromatic substitution on the heteroazulenes (6a-d) with paraformaldehyde to afford the corresponding disubstituted methane derivatives 7a-d, followed by oxidative hydrogen abstraction with DDQ, and subsequent exchange of the counter-anion by using aq. HPF₆ or aq. HBF₄. In addition, the reaction of 7a-d with 2.2 equiv. amounts of DDQ afforded carbonyl compounds 12a-d. The delocalization of the positive charge of 9a-c was evaluated by the ¹H and ¹³C NMR spectral data. The thermodynamic stability of cations 9a-c was evaluated to be in the order 9a<9b<9c on the basis of their reduction potentials measured by cyclic voltammetry (CV) and pK_R+ values (2.6-10.3) obtained spectrophotometrically. The reduction waves of cations 9a-c were irreversible, suggesting the dimerization of the radical species generated by one-electron reduction. This was demonstrated by the reduction of 9a·BF₄⁻ with Zn powder to give dimerized product 14a. In addition, the quenching of 9a·BF₄⁻ with MeOH/NaHCO₃ gives ether derivative 15a, which is proposed for the precursor for synthesizing tris(heteroazulene)-substituted methyl cations bearing two different heteroazulene-units.     

Bis heterocycles as potential chemotherapeutic agents. X. Synthesis of bis(4-arylthiosemicarbazido)-, bis(2-arylamino-1,3,4-thiadiazol-5-yl) and bis(4-aryl-1,2,4-triazolin-3-thione-5-yl)pentanes and related compounds

Synthesis of several bis(4-arylthiosemicarbazido- 1 , bis(2-arylamino-1,3,4-thiadiazol-5-yl)- 5 and bis(4-aryl-1,2,4-triazolin-3-thione-5-yl)- 2 pentanes is described. Sulphides 3 and sulphones 4 are also prepared from 2 by alkylation and subsequent oxidation with hydrogen peroxide respectively.     

油溶性缓蚀剂ω,ω’-双(1-辛基苯并咪唑-2-基)烷烃的合成及缓蚀性能研究

合成了系列ω,ω’-双(1-辛基苯并咪唑-2-基)烷烃油溶性缓蚀剂,并通过红外、质谱等进行结构表征。通过恒电位极化曲线,考察了此类缓蚀剂在2×10-4mol/L H2S-乙醇溶液中对铜电极极化曲线的影响。结果表明,此系列油溶性缓蚀剂对铜电极具有明显的缓蚀作用,且对金属铜的缓蚀效率高,作为润滑油添加剂具有很好的应用前景。     

Synthesis,structures, and properties of bis(4,6-disubstituted 1,3,5-triazin-2-yl) ethers

Reactions of (4,6-disubstituted 1,3,5-triazin-2-yl)trimethylammonium chlorides with glycine sodium salt in the presence of Et₃N afforded bis(triazin-2-yl) ethers instead of the expected triazinylaminoacetic acids. The structures of the resulting compounds were established by the independent synthesis, spectroscopic data, and X-ray diffraction analysis.     

Synthesis and reactivity of 2-(porphyrin-2-yl)-1,3-dicarbonyl compounds

A simple and efficient procedure for the synthesis of porphyrins bearing 1,3-dicarbonyl moieties at the β-position is described. The new compounds were further functionalized and new derivatives containing an heterocyclic ring, an ethyl acetate residue or a 2-oxopropyl group at the β-position have been obtained.     

Synthesis of bis(pyrrol-2-yl)arenes by Pd-catalyzed cross coupling

2-Borylpyrrole was prepared from 2-iodopyrrole almost quantitatively and then reacted with dihaloarenes under typical reaction conditions of Suzuki-Miyaura cross coupling to give bis(pyrrol-2-yl)arenes in good yields, while the cross coupling reaction of 2-iodopyrrole with 1,4-phenylenebisboronic acid was susceptible to oxidative self-coupling to produce 4,4′-bis(pyrrol-2-yl)biphenyl as a byproduct. These bis(pyrrol-2-yl)arenes showed strong fluorescence.     

Bromoiodinanes with an I(III)-Br bond: preparation, X-ray crystallography and reactivity as electrophilic brominating agents

Bromoiodinanes--conveniently and directly prepared from iodobenzenecarbinols and N-bromosuccinimide, and characterised for the first time crystallographically--act as electrophilic bromine donors.     

Oxidation reactivity channels for 2-(pyridin-2-yl)-N,N-diphenylacetamides

Synthetic routes to 2-(pyridin-2-yl)-N,N-diphenylacetamide and 2-(6-methylpyridin-2-yl)-N,N-diphenyl-acetamide are described along with results from the chemical oxidation of these compounds with peracetic acid, m-chloroperbenzoic acid, and OXONE. In each case, oxidations generate four products in varying amounts depending on the oxidant and reaction conditions. Each product has been characterized by spectroscopic methods and the molecular structures of several of the new compounds have been confirmed by X-ray crystallography.     

Synthesis,spectral and electrochemical properties of mixed-ligand ruthenium(II) complexes of bis(pyrid-2-yl)- and bis(benzimidazol-2-yl)-dithioether ligands: Effect of an asymmetric diimine co-ligand

Two new mixed-ligand Ru(II) complexes [Ru(pdto)(dppt)](ClO₄)₂ (1) and [Ru(bbdo)(dppt)](ClO₄)₂ (2), where pdto = 1,8-bis(pyrid-2-yl)-3,6-dithiaoctane, bbdo = 1,8-bis(benzimidazol-2-yl)-3,6-dithiaoctane and dppt = 3-(pyridin-2-yl)-5,6-diphenyl-1,2,4-triazine, have been isolated and characterised by elemental analysis. NMR and electronic absorption and emission spectral and electrochemical techniques have been used to investigate the solution structures and electronic properties of the complexes. The ¹H and ¹³C spectra of the complexes in solution reveal that the N₂S₂ donor set of the pdto and bbdo ligands is “cis-α” coordinated and the dppt ligand is chelated to Ru(II) through both triazine N2 and pyridine nitrogen atoms. The proton chemical shifts of the phenyl rings of dppt are not affected much upon coordination, supporting the triazine N2 rather than N4 coordination. The anomalous upfield shifts of the H₆₁ and H₆₂ (1) and H₇₂ and H₈₁ (2) protons are caused by the shielding magnetic anisotropy due to the ring currents of the py and tra rings of dppt, which are forced to be coplanar by coordination. The py and bzim rings of pdto and bbdo are obliged to rotate away from dppt and the Ru–N_py and Ru–N_bzim bonds lengthen in order to minimise the steric clashes with dppt. The c.i.s values for 1 are less positive than those for 2 suggesting that the ligand bzim nitrogens of bbdo rather than the py nitrogens of pdto are involved in stronger σ-bonding with Ru(II). Both the complexes display a strong MLCT transition (1, 470; 2, 515 nm) along with intense intraligand transitions in the UV region, and when excited in the MLCT band an emission band (650 nm) is observed for both 1 and 2. In acetonitrile solution they show a quasi-reversible Ru(II)/Ru(III) redox couple (E_1/2, 1, 1.18; 2, 0.90 V). Two more redox processes (E_1/2, 1, −0.97, −1.09; 2, −1.06, −1.42 V) involving the coordinated dppt ligand are also observed. A plot of the difference between the metal oxidation and ligand reduction potentials of the complexes versus the absorption or emission maxima is linear, illustrating that the lowest π^∗ orbitals of dppt are involved in the redox, absorption and emission processes in the complexes. Electrochemical parameterisation of the Ru(II)/Ru(III) redox potentials of the present complexes has been carried out using Lever’s method and the calculated ligand reduction potential E_L(L) correlates well with the observed Ru(II)/Ru(III) redox potentials.     

Synthesis and molecular structure of piperazidine-bridged bis(phenolate) samarium(II) complex and its reactivity to carbodiimides

The reaction of Sm[N(TMS)(2)](2)(THF)(2) with H(2)L (L = 1,4-bis(2-hydroxy-3-tert-butyl-5-methyl-benzyl)-piperazidine) afforded [SmL(HMPA)(2)](4)·8THF 2 upon treatment with 2 equivalents of HMPA (hexamethyl phosphoric triamide). X-ray crystallographic analysis of 2 reveals a tetrametallic macrocyclic structure, which represents the first example of a crystal structure of a Sm(II) complex stabilized by heteroatom bridged bis(phenolate) ligands. Reduction of carbodiimides RNCNR (R = (i)Pr and Cy) by [SmL](2)(THF) 1, which was formed in situ by the reaction of Sm[N(TMS)(2)](2)(THF)(2) with H(2)L in THF, yielded the Sm(III) complex with an oxalamidinate ligand [LSm{(N(i)Pr)(2)CC(N(i)Pr)(2)}SmL]·THF 3 for (i)PrNCN(i)Pr and the Sm(III) complex with a diamidocarbene ligand [LSm(μ-CyNCNCy)SmL]·5.5THF 4 for CyNCNCy.     

Synthesis of bis(2-chloroethyl)amino-1,8-naphthyridines for evaluation as anticancer agents

Some 1,8-naphthyridine nitrogen mustards have been synthesized for studies of their antitumor potentialities. All the tested intermediate and target compounds are devoid of antitumor properties.     

Synthesis and spectroscopic characterization of silver(I) complexes with the bis(1,2,4-triazol-1-yl)alkane ligand tz2(CH2). X-ray structures of two- and three-dimensional coordination polymers

1:1 AgX:tz(2)(CH(2)) (X = NO(3), NO(2), ClO(4)), 3:4 (X = O(3)SCF(3) (=OTf), O(2)CCF(3) (= tfa)), and 2:1 adducts (X = BrO(3)) have been synthesized and characterized in the solid state and in solution by analyses, spectral (IR, far-IR, (1)H and (13)C NMR, ESI MS) data, and conductivity measurements. The crystal structures of the 1:1 AgNO(3):tz(2)(CH(2)) and AgNO(2):tz(2)(CH(2)) adducts determined by X-ray studies show that tz(2)(CH(2)) coordinates to silver through the exodentate nitrogen atoms at the 4-positions of the triazole rings, yielding neutral polymers, while the ionic Ag(OTf):tz(2)(CH(2)) (3:4) adduct has a three-dimensional polymeric cation. The NMR and ESI MS data suggest that tz(2)(CH(2)) is only weakly coordinating, adducts between Ag(I) and CH(3)CN being more prevalent in acetonitrile solution.