Synthesis and thermal transformations of molecular complexes of bis[tris(trifluoromethyl)germyl]mercury(ii witho-quinones

Stable molecular complexes of bis[tris(trifluoromethyl)germyl]mercury(II) Hg[(CF₃)₃Ge]₂ (1) witho-quinones (3,6-di-tert-butylbenzoquinone-1,2 (2), 3,6-di-tert-butyl-4,5-dimethoxybenzoquinone-1,2 (3), and 1,4,5,7-tetra-tert-butyldibenzo[1,4]dioxin-2,3-dione (4)) have been synthesized and characterized by elemental analysis and IR and electronic absorption spectroscopies. Depending on the ratio between the starting reactants, the reactions ofo-quinones with1 gave complexes of the composition R₂Hg · Q (5,7,9) or R₂Hg · Q₂ (6,8,10), where Q=2 (5,6),3 (7,8),4 (9,10); R=Ge(CF₃)₃. According to the spectral data, the molecule ofo-quinone in R₂Hg · Q acts as a neutral ligand, whereas the second molecule ofo-quinone in R₂Hg · Q₂ is not coordinated to1. It has been found by ESR that thermolysis of polycrystalline samples of complexes6 and10 involves intermediate formation of radical pairs and finally yields paramagnetico-semiquinone complexes, SQGe(CF₃)₃, which are typical products of one-electron oxidation of Organometallic compounds byo-quinones.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1568–1573, August, 1995.The authors wish to thank M. A. Lopatin for his help in recording the electronic absorption spectra.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No. 93-03-18369).     

Beiträge zur Chemie des Phosphors. 221 [1]. Stannylsubstituierte Bicyclo [1.1.0]tetraphosphane: Bildung und Eigenschaften von R3Sn(H)P4 (R  CH3, C6H5, c-C6H11, o-C7H7)

Contributions to the Chemistry of Phosphorus. 221. Stannyl-Substituted Bicyclo[1.1.0]tetraphosphanes: Formation and properties of R₃Sn(H)P₄ (R ? CH₃, C₆H₅, c-C₆H₁₁, o-C₇H₇) The unsymmetrically substituted bicyclo[1.1.0]tetraphosphanes Me₃Sn(H)P₄ ( 1 ), Ph₃Sn(H)P₄ ( 2 ), (c-Hex)₃Sn(H)P₄ ( 3 ) and (o-Tol)₃Sn(H)P₄ ( 4 ) have been obtained by reaction of a solution of (Na/K) HP₄ with R₃ SnCl (R ? Me, Ph, c-Hex, o-Tol) under proper conditions. The structure of the compounds 1 – 4 , which are only stable in solution, has been elucidated by means of ³¹P-NMR-spectroscopy. Whereas 3 exists at ?60°C as the exo,endo isomer, 1, 2 and 4 are fluctuating molecules at room temperature and probably invert between the three possible configurational isomers (exo,exo-, exo,endo- and endo,endo-form).     

First attempts at differential diastereoselection in catalytic reactions of N-chirally substituted dirhodium(ii) tetrakis[methyl 2-oxoimidazolidine-4(S)-carboxylates] with diazoacetates

Chiral attachments on 2-oxoimidazolidine-4(S)-carboxylate ligands for dirhodium(ii) can provide differential diastereoselection in catalytic reactions of diazo compounds. The synthesis of these heterocyclic ligands from the readily available amino acid asparagine is reported. Reactions with diazoacetates offering intramolecular carbon—hydrogen insertion provide evaluative data that demonstrate differential diastereoselection. Surprisingly, placement of a carbonyl group within the chiral attachment removes enantiocontrol from the catalyst, presumably because of intramolecular ylide formation.     

Komplexchemie P-reicher Phosphane und Silylphosphane. VII [1]. Bildung und Struktur von [Li(DME)3]2{(SiMe3)[Cr(CO)5]2 P?PP?P[Cr(CO)5]2(SiMe3)}

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VII. Formation and Structure of [Li(DME)₃]₂{(SiMe₃)[Cr(CO)₅]₂ P-P ? P-P[Cr(CO)₅]₂(SiMe₃)} Deep red crystals of the title compound 1 are produced in the reaction of LiP(Me₃Si)₂[Cr(CO)₅] with 1, 2-dibromoethane in DME. The structure of 1 was derived from the investigation of the ³¹P-NMR spectra and confirmed by a single crystal structure determination. 1 crystallizes in the space group P1 (no. 2); a = 1307.8(5)pm, b = 1373.1(5)pm, c = 1236.1(4)pm, α = 106.22(4)°, β = 88.00(3)°, γ = 115.52(4)° and Z = 1. 1 forms a salt composed of a dianion R₂R₄′P₄^2? (R ? SiMe₃, R′ ? Cr(CO)₅) and solvated Li⁺ cations. The zigzag shaped dianion possesses the symmetry 1 -C_i. The distances d(P? P) = 202.5(1)pm and d(P? P) = 221.9(1)pm correspond to a double bond and single bonds, respectively. The distances d(Cr? P) = 251.1(1) pm and 255.3(1) pm are larger than those observed so far which might be caused by the charge distribution in the dianion.     

Synthesis,characterization and thermal analysis of [Fe(N2H4)2(CH3COO)2]

[Fe(N₂H₄)₂(CH₃COO)₂] was synthesised and characterized for the first time by chemical analysis, magnetic measurements, electronic and IR spectral studies. Its thermal reactivity was ascertained by thermogravimetric (TG) and derivative thermogravimetric (DTG) techniques and it has been concluded that unlike some other metal carboxylate hydrazinates, it does not show any autocatalytic behaviour. The decomposition was also subjected to kinetic analysis using the equations of Coats-Redfern and Horowitz-Metzger by the method of weighted least-squares.     

Hypercoordinated diorganoantimony(III) compounds of types [2-(Me2NCH2)C6H4]2SbL and [PhCH2N(CH2C6H4)2]SbL (L = Cl,ONO2, OSO2CF3). Synthesis,structure and catalytic behaviour in the Henry reaction

The compounds [2-(Me₂NCH₂)C₆H₄]₂SbL (L = ONO₂ ( 2 ), OSO₂CF₃ ( 3 )) and [PhCH₂N(CH₂C₆H₄)₂]SbL (L = ONO₂ ( 5 ), OSO₂CF₃ ( 6 )) were prepared by reacting [2-(Me₂NCH₂)C₆H₄]₂SbCl ( 1 ) and [PhCH₂N(CH₂C₆H₄)₂]SbCl ( 4 ), respectively, with the appropriate silver(I) salt in a 1:1 molar ratio. The new species 2 – 6 were structurally characterized in solution using multinuclear NMR and in the solid state using infrared spectroscopy. The solid-state structures for compounds 2 , 4 and 6, as well as for the hydrolysis ionic product [{2-(Me₂N⁺HCH₂)C₆H₄}{2-(Me₂NCH₂)C₆H₄}SbOH][CF₃SO₃]⁻ ( 3h ) were determined using single-crystal X-ray diffraction. Medium to strong intramolecular N→ Sb interactions were observed in all these four compounds, thus resulting in hypercoordinated organoantimony(III) species 14-Sb-6 in 2 and 10-Sb-4 in the cation of 3h and in 4 and 6 . Compounds 1 – 6 and the starting amines PhCH₂NMe₂ and PhCH₂N(CH₂C₆H₄Br-2)₂ were investigated as catalysts in the Henry (nitroaldol) addition of nitromethane to benzaldehyde. The activity of compounds 1 – 6 resulted as an effect of the cooperation of the positively charged antimony with the negatively charged nitrogen.     

Low-temperature X-ray study of benzoid-quinoid tautomerism in crystals of 2-(N,N-diphenylhydrazinoethylidene)-3(2H)-benzo[b]thiophenone

An X-ray investigation of 2-(N,N-diphenylhydrazinoethylidene)-3(2H)-benzo[b]thiophenone was performed at room and low (–80 °C) temperatures. It was established that the structure of this compound in the crystalline state at R-20 °C is intermediate between the ketoenehydrazine and hydroxyhydrazone forms, while at –80 °C the molecular structure is completely transformed to the hydroxyhydrazone form. This confirms the dynamic nature of hydrogen atom disordering in the molecule at 20 °C.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 104–106, January, 1995.This work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-04355).     

Crystallographic report: Bis(acetato‐O,O′){4‐[N,N‐bis(2‐cyanoethyl)amino] pyridine}bis(methanol)cadmium(II), [Cd(C11H12N4) (CH3CO2)2(CH3OH)2]

The cadmium atom is coordinated in distorted pentagonal bipyramidal geometry by the pyridine‐nitrogen atom of the 4‐[N,N‐bis(2‐cyanoethyl)amino]pyridine ligand, two oxygen atoms of two methanol molecules and four oxygen atoms of two acetate groups. Copyright © 2005 John Wiley & Sons, Ltd.     

Reaction of 6-methoxybenzo[b]furan-3(2H)-one and benzo[b]thiophen-3(2H)-one with 2-aryl-1,1-dicyanoethylenes as a convenient synthetic route to substituted 2-amino-4-aryl-1,3-dicyano-7-methoxydibenzo[b,d]furans and 2-amino-4-aryl-3-cyano-4H-benzothieno[3,2-b]pyrans

The reactions of 6-methoxybenzo[b]furan-3(2H)-one with 2-aryl-1,1-dicyanoethylenes and malononitrile or with aromatic aldehyde and two moles of malononitrile afford 2-amino-4-aryl-1,3-dicyano-7-methoxydibenzo[b,d]furans. The reactions of benzo[b]thiophen-3(2H)-one with 2-aryl-1,1-dicyanoethylenes or with aromatic aldehyde and one mole of malononitrile produce 2-amino-4-aryl-3-cyano-4H-benzothieno[3,2-b]pyrans.     

2-[3-(Trifluoromethyl)phenyl]furo[3,2-b]pyrroles: synthesis and reactions

The synthesis and reactions of methyl 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole-5-carboxylate (1a) are described. Upon reaction with methyl iodide, benzyl chloride, or acetic anhydride, this compound gave N-substituted products 1b-d. By hydrolysis of compounds 1a-c, the corresponding acids 2a-c were formed, or by reaction with hydrazine-hydrate, the corresponding carbohydrazides 3a-c were formed. By heating 2-[3-(trifluoromethyl)phenly]-4H-furo[3,2-b]pyrrole-5-carboxylic acid (2a) in acetic anhydride, 4-acetyl-2-[3-(trifluoromethyl)phenyl]furo[3,2-b]pyrrole (4) was formed. By hydrolysis of 4, 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole (5a) was formed, and reactions with methyl iodide or benzyl chloride gave N-substituted products 5b-c. The reaction of 4 with dimethyl butynedioate gave substituted benzo[b]furan 6. Compound 3a reacted with triethyl orthoesters giving 7a-c, which afforded with phosphorus (V) sulphide the corresponding thiones 8a-c. The thiones 8a-c reacted with hydrazine hydrate to form hydrazine derivatives 9a-c. The reaction of triethyl orthoformiate with compounds 9a-c led to furo[2′,3′: 4,5]pyrrolo[1,2-d][1,2,4]triazolo[3,4-f][1,2,4]triazines 10a-c. Hydrazones 11a-c were formed from 3a-c and 5-[3-(trifluoromethyl)phenyl]furan-2-carboxaldehyde. The effect of microwave irradiation on some condensation reactions was compared with “classical” conditions. The results showed that microwave irradiation shortens the reaction time while affording comparable yields.     

Oxadiazole condensed ring systems,II: Synthesis of new 2-aryl-1,3,4-oxadiazolo[3,2-a]-s-triazine-5,7(6H)-diones

Summary The syntheses of 1,3,4-oxadiazolo[3,2-a]-s-triazine-5,7(6H)-diones4 through the condensation of 2-amino-5-aryl-1,3,4-oxadiazoles1 with ethoxycarbonyl isocyanate2 is described. Methylation of4b with trimethyl phosphate yielded the N-methyl derivative5.

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Kondensierte Ringsysteme des Oxadiazols, 2. Mitt. [1]: Synthese von neuen 2-Aryl-1,3,4-oxadiazolo[3,2-a]-s-triazin-5,7(6H)-dionen

Zusammenfassung Die Synthese von 1,3,4-Oxadiazolo[3,2-a]-s-triazin-5,7(6H)-dionen4 durch Kondensation von 2-Amino-5-aryl-1,3,4-oxadiazolen1 mit Ethoxycarbonylisocyanat2 wird beschrieben. Die Methylierung von4b mit Trimethylphosphat gibt das N-Methyl-Derivat5.

     

Sodium bis(2-methoxyethoxy)aluminum hydride in reactions with 3-cyano-6-methylpyridine-2(1H)-thione and 3-cyano-6-methyl(4,6-dimethyl)-2-methylthiopyridines

The reactions of sodium bis(2-methoxyethoxy)aluminum hydride with 3-cyano-6-methylpyridine-2(1H)-thione and 3-cyano-6-methyl-2-methylthiopyridine afforded 3-aminomethyl-6-methylpyridine-2(1H)-thione and azomethine of the pyridine series, respectively. The corresponding reaction with 3-cyano-4,6-dimethyl-2-methylthiopyridine gave rise to azomethine, substituted 3-aminomethylpyridine, and substituted dipyridylmethane.     

Eisen(II)—Phosphin-Komplexe Synthese und Kristallstrukturen von [Fe2I4(dppe)2], [Fe2(SR)4(dppe)2], [Fe(SR′)2(dppp)] und [Fe(SR)2(PMePh2)2] (dppe = Ph2P(CH2)2PPh2; dppp = Ph2P(CH2)3PPh2; R = 2,4,6-Me3C6H2; R′ = 2,4-tBuC6H3)

Iron(II) Phosphane Complexes. Synthesis and Crystal Structures of [Fe₂I₄(dppe)₂], [Fe₂(SR)₄(dppe)₂], [Fe(SR′)₂(dppp)] and [Fe(SR)₂(PMePh₂)₂] (dppe = Ph₂P(CH₂)₂PPh₂; dppp = Ph₂P(CH₂)₃PPh₂; R = 2,4,6-Me₃C₆H₂; R′ = 2,4-tBuC₆H₃) The title compounds were isolated and their structures determined by crystallographic methods. [Fe₂I₄(dppe)₂] ( 1 ) and [Fe₂(SR)₄(dppe)₂] ( 2 ) form dimeric complexes with the bidentate phosphane binding to different iron atoms. The resulting ten-membered rings of both compounds exhibit a nearly identical conformation. The central FeS₂P₂ units of the mononuclear complexes [Fe(SR′)₂(dppp)] ( 3 ) and [Fe(SR)₂(PMePh₂)₂] ( 4 ) show like 2 large deviations from ideal C_2v symmetry with bonding angles around the central iron atom ranging from 97.2, 92.5, and 96.5° (angle P? Fe? P in 2, 3 , and 4 , respectively) to 129.0, 129.9, and 133.6° (angle S? Fe? S in 2, 3 , and 4 , respectively).     

Schwefeldioxid als Ligand und Synthon. XII. Synthese und Reaktivität von Nickel(II)-Komplexen dreizähniger anionischer Liganden des Typs (C6H3{CH2NR1R2}2-2,6)−

Sulfur Dioxide as Ligand and Synthon. XII. Synthesis and Reaction Behaviour of Nickel(II) Complexes with Terdendate Anionic Ligands of the Type (C₆H₃{CH₂NR¹R²}₂?2,6)^? Organonickel(II) complexes of the type [NiX{C₆H₃(CH₂NR¹R²)₂?2,6}] (X = halide OH₂⁺/CF₃SO₃^?; R¹?R²?Et 1 ; R¹?R²?i? Pr 2 ; R¹ = Me, R² = Cy 3 ; (NR¹R²) = piperidino 4 ; (NR¹R²) = pyrrolidino 5 ) are described. ¹H and ¹³C NMR and UV/Vis spectra were recorded, and the X-ray crystal structure of 1 a (X = Br) was determined. This complex crystallizes orthorhombically in the space group Pbca with a = 1 335.8(2) pm, b = 1 903.3(3) pm, c = 1 365.4(3) pm and Z = 8, and has an approximately square-planar geometry. 4 and 5 show a reversible binding of SO₂ which has been detected by means of IR photoacoustic spectroscopy. The reactions of 1 – 5 with CS₂ and PhNSO are discussed.     

OH−-induced β-elimination reactions with 1-(2-Xethyl)-4-nitrobenzene substrates in solvent mixture H2O/CH3CN and H2O/DMSO: Reactivity and mechanism

The behaviour of 1-(2-bromoethyl) 4-nitrobenzene (1), N,N,N-triethyl-2-(4-nitrophenyl)ethanaminium bromide (2) and N,N-diethyl-N-[2-(4-nitrophenyl)ethyl]octan-1-aminium bromide (3) in the OH⁻-induced elimination reactions with formation of 1-nitro-4-vinylbenzene in mixtures of DMSO/H₂O or CH₃CN/H₂O has been investigated. With all three substrates an increase in dipolar aprotic solvent content implies a limited increase of the second-order rate constant k _OH up to ≅605, and then an exponential increase is observed. The variation of activation parameters ΔH ^# and dGS ^#, measured in DMSO/H₂O mixtures, is parallel for 1 and 2. This similar behaviour of 1 and 2 with respect to variation in solvent composition is evidence that it is not possible to use this technique of solvent effect for the mechanistic diagnosis of elimination reactions.     

Deoxypegan-1-one derivatives. synthesis and borohydride reduction of 3-[(E)-arylmethylidene]-3,9-dihydropyrrolo[2,1-b]quinazolin-1(2H)-ones

3-[(E)-Arylmethylidene]-3,9-dihydropyrrolo[2,1-b]quinazolin-1(2H)-ones were prepared by reaction of quinazolyl-2-propionic acid hydrochloride with aromatic aldehydes in acetic anhydride in the presence of Et₃N. 3-[(E)-Arylmethylidene]-1,2,3,9-tetrahydropyrrolo[2,1-b]quinazolin-1-ols were formed by reduction of the 3-arylidene derivatives with sodium borohydride in methanol, readily lost water when heated with acids, and were converted into 3-[(E)-arylmethylidene]-3,9-dihydropyrrolo[2,1-b]quinazolines. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 463–467, September–October, 2006.     

Synthesis of 3-acetyl-4-amino-6-arylpyran-2-ones and ethyl 7-aryl-4,5(1H,5H )-dioxopyrano[4,3-b]pyridine-2-carboxylates

The reactions of aroylacetonitriles with the nickel chelate of ethyl acetoacetate afforded new block heterocyclic reagents, viz., 3-acetyl-4-amino-6-arylpyran-2-ones. The reactions of the latter with diethyl oxalate gave rise to ethyl 7-aryl-4,5(1H,5H)-dioxopyrano[4,3-b]pyridine-2-carboxylates.     

Syntheses based on 2-ethoxycarbonylmethyl-7-methyl-1,3,4-thiadiazolo[3,2-a]pyrimidin-5(5H)-one

2-Ethoxycarbonylmethyl-7-methyl-1,3,4-thiadiazolo[3,2-a]pyrimidin-5(5H)-one containing the active methylene group reacts easily with carbon disulfide and phenyl isothiocyanate in the presence of sodium hydride. Further alkylation of the reaction product by alkyl halides results in the formation of the corresponding 1,3,4-thiadiazolo[3,2-a]pyrimidine derivatives containing a ketene dithioacetal fragment. Deceased. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2371–2373, November, 1998.     

Synthesis, Crystal Structure and Electrochemical Properties of One-dimensional Chain Coordination Polymer [Co(Ⅱ)(C6H5CH=CHCOOH)2(4,4''-bipy)(H2O)5]n

A one-dimensional chain coordination polymer [Co(Ⅱ)(C6H5CH=CHCOOH)2(4,4'-bipy)(H2O)5]n has been synthesized with cinnamylic acid, 4,4'-bipy and cobaltous chloride as raw materials. Crystal data for this complex: monoclinic, space group P21/c, a - 1.1481(3), b =1.1230(2), c = 1.1759(3) nm, β = 97.054(4)°, V = 1.5046(6) nm3, Mr= 617.50, Dc = 1.363 g/cm3, Z= 2, μ(MoKα) = 0.627 mm-1, F(000) = 646, S = 1.062, R 0.0443 and wR = 0.1178. The crystal structure shows that two neighboring cobalt(Ⅱ) ions are linked together by one 4,4'-bipy, and the whole complex molecule adopts a one-dimensional chain structure. Each cobalt(Ⅱ) ion is coordinated with two nitrogen atoms from two 4,4'-bipy molecules and four oxygen atoms from four water molecules, giving a distorted octahedral coordination geometry. The electrochemical properties were analyzed by combining with the crystal structure.