Synthesis of benzoates of 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis-(2,5-dimethyl-4-hydroxypiperidino)-2-butyne

1,4-Bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butyne (II and III) were obtained by the action of 1,4-dibromo-2-butene and 1,4-dibromo-2-butyne on the form of 2,5-dimethyl-4-piperidol (I). The benzoates (IV and V) were obtained by acylation of II and III with benzoyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 352–353, March, 1971.     

New method for the synthesis of 1,4-enynes by the cross-coupling of magnesium acetylides with allyl compounds

Conclusions A method was developed for the synthesis of 1,4-enynes by the cross-coupling of compounds of type (RCC)₂Mg and RCCMgBr with allyl alcohol derivatives using Ni(acac)₂-Ph₃P as the catalyst.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 907–908, April, 1984.     

Oligomerization and co-oligomerization of α-olefins catalyzed by nickel(II)/alkylaluminum systems

This work describes α-olefins oligomerization/co-oligomerization of 1-butene, 1-hexene, 1-octene to linear oligomers (C₈---C₁₆ range) promoted by catalytic systems based on nickel(II) salts/alkylaluminum compounds. Conversion, selectivity (isomerization or oligomerization) and linearity are determined by mass distribution calculation of the substrates (α-olefins) in the products. The best results are obtained with Ni(acac)₂/AlEt₂OEt working at 60°C, Al/Ni ratio between 0.8–1.4 and using toluene as a solvent. Under these conditions, the conversion is higher than 90% giving 40% of oligomerization selectivity. The linearity varies from 65% (C₁₆ fraction) to 98% (C₈ fraction).     

Composition catalysts of ethylbenzene oxidation based on bis(acetylacetonato)nickel(ii) and phase transfer catalysts as ligands 1. Macrocyclic polyethers

The addition of the macrocyclic polyether 18-Crown-6 (18C6) increases the selectivity of oxidation of ethylbenzene to -phenylethylhydroperoxide (PEH) in the presence of Ni(acac)₂. The initial oxidation rate, selectivity and degree of conversion of ethylbenzene to PEH are greater than those catalyzed by Ni(acac)₂ only. The efficiency of the macrocyclic ligand as an activator of Ni(acac)₂ exceeds that of monodentate donor ligands. The high selectivity of the process is due to both the primary Ni(acac)₂ · 18C6 complexes and the products of their transformation in the course of oxidation. The mechanism of ethylbenzene oxidation catalyzed by Ni(acac)₂ · 18C6 complexes is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1406–1411, August, 1994.     

Mössbauer study of paramagnetic relaxation effect in mixed crystals: High spin Fe3+ compounds diluted in diamagnetic hosts

The⁵⁷Fe Mössbauer spectra were measured in mixed crystals with different types of chemical bonding and crystal structure, i.e., (Fe,Al)(acac)₃, (Fe,Co)(acac)₃, K₃[(Fe,Al)(ox)₃]3H₂O, and NH₄(Fe,Al)(SO₄)₂12H₂O. The broadening of Mössbauer linewidth with increasing Fe³⁺–Fe³⁺ distance became less enhanced in the order: (Fe,Al)(acac)₃>(Fe,Co)(acac)₃, or K₃[(Fe,Al)(ox)₃]3H₂O>(Fe,Al)(acac)₃>NH₄(Fe,Al)(SO₄)₂12H₂O. Furthermore, it was found that the broadening of the linewidth was larger in neat tris (-diketonato) iron(III) complexes than in (Fe,Al)(acac)₃. Based on these results, the determining factors of the paramagnetic relaxation time other than Fe³⁺–Fe³⁺ distance and temperature were examined in terms of the Mössbauer linewidth as an indicator.     

X-ray diffraction study of 1,2-bis(methylidene-2,2-dimethyl-hydrazino)ethylene — product of the oxidation of 1,1,2-trisubstituted hydrazines [1,1-dimethyl-2-(2-cyanoethyl)hydrazine]

It was established by x-ray diffraction analysis of crystals with the composition C₁₀H₁₄N₆ [a=14.869(2), b=11.405(2), c=7.585(1) Å, =107.53(1), d_calc=1.18 g·cm^–3, Z=4, and space group P2₁/c] that the molecule has a linear rather than a cyclic structure and is 1,2-bis(methylidene-2,2-dimethylhydrazino)ethylene rather than 1,4-bis(dimethylamino)-2,5-dicyano-1,4-dihydropyrazine as previously assumed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 541–544, April, 1978.     

Metathesis reactions of allylsilanes containing bulky aromatic substituents

Bulky substituents, such as -naphthyl and ferrocenyl groups, do not inhibit the metathesis of allylsilanes on a Re₂O₇/Al₂O₃-SnBu₄, catalyst system. Metathesis represents a preparative synthetic method for the synthesis of 1,4-bis(-napthyl-dimethylsilyl)- and 1,4-bis(ferrocenyldimethylsilyl)but-2-enes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1207–1209, May, 1991.     

Synthetic Approaches to Mixed-Metal Heteroleptic Derivatives of Late Transition Metals

The approach based on isomorphous substitution permitted preparation of (Co, Ni)₄(acac)₄(₃–OMe)₄(MeOH)₄(I) via interaction of individual M₄(acac)₄(₃–OMe)₄(MeOH)₄ in toluene/methanol media. The oxidation of I in air in solution in MeOH in the presence of NaOAc and aminoalcohols as catalysts gives Co₂Ni₂-(acac)₄(₃–OMe)₄(OAc)₂(II). The symmetrization reaction between a complex formed by a hard Pearson acid and a soft Pearson base and that formed by a soft acid and a hard base led to CuNi₂(OCOC₂H₅)₃(OR^N)₃-(R^NOH)(III) and Ni(Ni_0.25Cu_0.75)₂(₃–OH)(₂–OAc)(OAc)₂(₂, ²-OR^N)₃(²-R^NOH)(IV) R^N = CH(CH₃)-CH₂NMe₂ via interaction of Ni(OR^N)₂ with copper propionate and copper acetate hydrate respectively in hydrocarbon media.     

Vibrational Spectroscopic Study of [1,2-bis(4-pyridyl)ethane]metal(II) Tetracyanonickelate(II). 2 m-Xylene Clathrates

Four new Hofmann-type clathrates of the form M(bpa)₂Ni(CN)_4· 2m-xylene (M = Mn , Fe , Co and Ni; bpa = 1,2-bis(4-pyridyl)ethane) have been synthesized and characterized by vibrational spectroscopy. The M(bpa)₂Ni(CN)₄ (M = Fe and Co) host structure is similar to the classical Hofmann-type host framework composed of layers of a two dimensional catena-metal tetra--cyanonickelate(II) network, but in M(bpa)₂Ni(CN)₄ (M = Mn and Ni), the Ni(CN)₄ moiety behaves as a bidentate –[NC-Ni(CN)₂-CN–]– unit in the host framework.     

Separation of lanthanum,cerium and samarium from uranium samples

The radiation reduction yield of Fe³⁺ in complexes with various ligands (Cl^–, SO ₄ ^2– , CN^–) in methanol-water solutions has been studied. The effect of the dose, pH, scavenger concentration and matrix composition on the reduction, yield of Fe³⁺ in the above complexes and in Fe(acac)₃ was determined. Studies of methanol-water glasses (91) provided some interesting observations as to the effectiveness of scavenging the electrons by various ferric compounds. The effectiveness of scavenging decreases in the series Cl^–>SO ₄ ^2– >CN^–. As opposed to Co(acac)₃, Fe(acac)₃ appeared to be an ineffective scavenger.     

Reaction of 1,4-bis(trimethylsilyl)-2-butene with aromatic aldehydes catalyzed by TiCl4: an approach to (1-vinylallyl)benzene type derivatives

1,4-bis(Trimethylsilyl)-2-butene 1 can react with alkyl and aromatic aldehydes in the presence of titanium tetrachloride to give α-(trimethylsilyl)methyl homoallylic alcohols and (1-vinylallyl)benzene type compounds in poor to good yield according to the related position of each substituents present on the aromatic ring. In the last case, the reaction involves a type electrophilic substitution of 1,4-bis(trimethylsilyl)-2-butene by aromatic aldehydes activated by TiCl₄, followed by a 1,2-migration of a vinyl group.     

Dimerization of vinylcyclopropane and its codimerization with 1,3-dienes catalyzed by cobalt complexes

Conclusions The dimerization of vinylcyclopropane to 2-cyclopropyl-1,5(Z)-heptadiene and the codimerization of vinylcyclopropane with 1,3-dienes (butadiene, isoprene, and 2-cyclopropylbutadiene) with the formation of 2-cyclopropyl-1,4-hexadienes were carried out in the presence of the catalytic systems Co(acac)₃-1,2-bis(diphenylphosphino)ethane [1,2-bis(diphenylphosphino)methane]-AlEt₂Cl.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1356–1360, June, 1988.     

Oxidation of aromatic compounds: XII. Regio- and stereoselective oxidative dimerization of alkyl 3-arylpropynoates in the system CF<Subscript>3</Subscript>CO<Subscript>2</Subscript>H-CH<Subscript>2</Subscript>Cl<Subscript>2</Subscript>-PbO<Subscript>2</Subscript>

Regio- and stereoselective oxidative dimerization of alkyl 3-arylpropynoates in the system CF₃CO₂H-CH₂Cl₂-PbO₂ (1–30 h, 0–20°C) leads to dialkyl (E)-2,3-bis(arylcarbonyl)-2-butene-1,4-dioates with trans arrangement of the substituents at the double bond.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1329–1333.Original Russian Text Copyright © 2004 by Savechenkov, Vasilev, Rudenko.For communication XI, see [1].     

The mechanisms of the acid-catalysed dissociation of tris-β-diketonatoruthenium(III) complexes

Summary The reactions of four -diketonatoruthenium(III) complexes in the presence of HNO₃ andp-MeC₆H₄SO₃H in the 45° and 57° range were followed spectrophotometrically in Me₂COH₂O mixtures. Dissociation of Ru(acac)₃ follows [H⁺]-dependent and [H⁺]²-dependent paths, whereas the bzac and F₃acacF₃ complexes follow only the [H⁺]-dependent path. The bzbz (Dibenzoylmethanate) complex is inert. Protonation of the bound ligand leads to its rupture from the metal ion. The bzac complex is kinetically more inert than the acac complex, because of extra stability arising from interaction of the (bzac) benzene ring with the pseudo-aromatic diketonate ring of the complex. Considering the kinetic labilities, the complexes may be arranged in the order Ru(F₃acacF₃)₃>Ru(acac)₃>Ru(bzac)₃>Ru(bzbz)₃.Activation parameters for [H⁺] dependent path are: H ₁ 86.5±7, 69±5, 121±7 kJ mol^–1, S ₂ –52±10, –107±10, 57±8 JK^–1 mol^–1 for acac, bzac and F₃acacF₃ complexes respectively and H ₂ 67±5 kJ mol^–1, S ₂ –92±8 JK^–1 mol^–1 for the acac complex only.     

Synthesis of N-unsubstituted ketene aminals from β-ketocarboxylic esters and cyanamide

The interaction of cyanamide with -ketocarboxylic esters in the presence of Ni(acac)₂ affords N-unsubstituted aminals of acyl(alkoxycarbonyl)ketenes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 419–421, February, 1993.     

Bis(2,4–pentanedionato)vanadium(IV) aryloxides

Complexes of composition [VCl(acac)2(OAr1–4)] and [V(acac)2(OAr1–4)2] (HOAr1=HOC6H4NO2–4, HOAr2= HOC6H4OMe-4, HOAr3=HOC6H4But-4 and HOAr4= HOC6H2But-2,6–Me-4; acac=2,4–pentanedionato ion) have been synthesized by the reaction of [VCl2(acac)2] with the respective phenols or their trimethylsilyl derivatives. The complexes have been characterized by physicochemical and spectroscopic techniques. They are non-electrolytes in nitrobenzene. Room temperature magnetic moments in the 1.71–1.82B range are consistent with the VIV system. The reactions of [VCl(acac)2(OAr2)] and [VCl(acac)2(OAr3)] with chloride acceptors have been studied by conductance techniques and the formation of ionic complexes of the types [V(acac)2(OAr2,3)][MCl4] (M=Fe, Al or Sb) and [V(acac)2(OAr2,3)][MCl6] (M=P or Sb) is indicated by the conductance composition curves. Several of these complexes have been isolated and characterized.     

A new convenient method for the synthesis of mixed-ligand β-diketonato Tc(III) complexes

A new convenient method has been proposed to synthesize mixed-ligand -diketonato Tc(III) complexes, using the ligand exchange reaction [Tc(acac)₂(CH₃CN)₂]⁺+L^–[Tc(acac)₂L]+ +2CH₃CN where L is bza, dpm or dbm. The yield was about 30–40%. UV-visible and IR spectra of these complexes were measured. Characteristic features of the compounds were compared with those of the corresponding complexes of ruthenium.     

Use of catalytic systems based on Ni in hydrogermylation of some 1,3-dienes with diethylbromogermane

Conclusions A catalytic system composed of Ni(acac)₂ and PPh₃ is an efficient catalyst for the hydrogermylation of conjugated dienes of variable structure with diethylbromogermane. The process is selective and leads to a 1,4-cis addition products.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 930–932, April, 1984.     

Mechanism of recoil implantation reactions of technetium and ruthenium in metal acetylacetonates

Recoil implantation of Tc and Ru in metal acetylacetonates were performed using ruthenium metal as a source and M^III/acac/₃ and M^II/acac/₂ complexes as catchers. The recoil atoms were obtained by¹⁰⁰Ru/, p/^99mTc and⁹⁸Ru/, n/⁹⁷Ru reactions. The yields of Tc/acac/₃ and Ru/acac/₃ were clearly dependent on the force constant of the bond between the central metal atom and oxygen in acetylacetone K/M–O/. A plot of the yield vs. 1/K(M–O) showed a linear relationship. However, the yield of Tc/acac/₂ implanted in M/acac/₂ did not show such a dependence on the force constant. The difference of the mechanism of complex formation between Tc/acac/₃ and Tc/acac/₂ was discussed on the basis of a reaction cage surrounding the recoil atom and of reaction time necessary for competition between the recoil atom and the central metal of the catcher complex.     

Synthesis of 1,3-thiazoline derivatives from β-dicarbonyl compounds and phenacyl thiocyanate

Acetylacetone and ethyl acetoacetate undergo addition at the CN bond of phenacyl thiocyanate in the presence of Ni(acac)₂ to give the respective keteneN, S-acetals, which undergo smooth cyclization to afford 2-methylene-4-phenyl-1, 3-thiazoline derivatives when refluxed in THF.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1938–1940, November, 1993