Crystalline β Modification of (BEDT-TTF)<Subscript>2</Subscript>Br<Subscript>0.12</Subscript>Cl<Subscript>1.88</Subscript>I

The structure of the crystalline β’ modification of a radical cation salt of bis(ethylenedithio)tetrathiafulvalene with mixed dihalogen iodide (BEDT-TTF)₂Br_0.12Cl_1.88I (I) was investigated by single crystal X-ray diffraction. Triclinic structure of I (space group , a = 6.638 Å, b = 9.779 Å, c = 12.920 Å; α = 87.24°, β = 79.10°, γ = 81.37°) was solved by direct methods and refined in a full-matrix anisotropic approximation to R = 0.030 using all 3897 measured independent reflections (CAD-4 automatic diffractometer, λMoK _α). In the crystal structure of I the mixed Cl*-I-Cl* anion occupies the inversion center i(000), its terminal atom having a composition Cl* = Cl_0.94Br_0.06. The semi-radical cation (C₁₀H₈S₈)^1/2+ has one of two ethylene groups disordered.Original Russian Text Copyright © 2004 by A. N. Chekhlov__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 960–965, September–October, 2004.     

Application of organolithium and related reagents in synthesis,Part X. Metallation-electrophilic substitution sequence of secondary chlorobenzamides

Summary The lithiation (Bu ⁿLi/THF) of 2-chloro- (1), 3-chloro- (2) and 4-chlorobenzanilides (3) and the subsequent reactions of the corresponding bis-lithiated anilides4–6 with electrophiles (MeI, CH₂=CH-CH₂Br,Me ₃SiCl,MeCHO,o-MeOC₆H₄CHO,p-MeOC₆H₄CHO,Me ₂NCHO andp-MeOC₆H₄CONMe ₂) towards the synthesis of theortho substituted chlorobenzoesic acids derivatives12–14 have been described. The effect of the chlorine substituent upon the generation and stability of the bis-lithiated chloro-anilides4–6 has been studied. It has been found that the bis-lithiated chloro-anilide5 derived fromm-chloro-benzanilide (2) at a temperature above –30°C converts into the corresponding benzyne9. The anilide moiety (masking group) of the formedortho-substituted chlorobenzanilides appeared to be effectively removable on acid-driven hydrolysis.

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Anwendungen von Organolithium und verwandten Reagenzien in organischen Synthesen, 10. Mitt. Metallierung und nachfolgende elektrophile Substitution sekundärer Chlorbenzamide

Zusammenfassung Die Lithiierung (Bu ⁿLi/THF) der 2-Chlor-(1), 3-Chlor- (2) and 4-Chlorbenzanilide (3) und nachfolgende Reaktion der entsprechenden doppellithiierten Anilide4–6 mit elektrophilen Reagenzien (MeI, CH₂=CH-CH₂Br,Me ₃SiCl,MeCHO,o-MeOC₆H₄CHO,p-MeOC₆H₄CHO,Me ₂NCHO undp-MeOC₆H₄CONMe ₂) zur Synthese vonortho-substituierten Benzoesäurederivaten12–14 wird beschrieben. Der Einfluß des Chlorsubstituierten auf die Bildung und Stabilität der doppellithiierten Chloranilide4–6 wurde untersucht. Es wurde festgestellt, daß das doppellithiierte, vomm-Chlorbenzanilid erhaltene Chloranilid5 bei Temperaturen über –30°C das entsprechende Arin9 bildet. Der Anilidrest (eine maskierende Gruppe) der gebildetenortho-substituierten Chloranilide kann durch saure Hydrolyse abgespalten werden.

     

Crystal structure and vibrational spectra of pyridine-2,6-dithio-carbomethylamide

The crystal structure of Pyridine-2,6-dithio-carbomethylamide (PDTA) is described: C₉H₁₁N₃S₂, monoclinic, P2₁/c,Z=4,a=6.000 (1) Å,b=8.840 (1) Å,c=21.452 (1) Å, =105.47 (1)^o,d _x=1.47 gcm^–3. The structure was solved with direct methods and refined to a conventionalR-factor of 0.047. The molecule is nearly planar in the crystal. There are possibly weak intramolecular H-bonds between the two amide nitrogens and the pyridine nitrogen and intermolecular H-bonds between two amide nitrogens and one thioamide sulfur atom. The IR andRaman spectra ofPDTA and deuteratedPDTA are discussed.

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Kristallstruktur und Schwingungsspektren von Pyridin-2,6-dithiocarbomethylamid

Zusammenfassung Die Kristallstruktur von Pyridin-2,6-dithiocarbomethylamid (PDTA) wurde bestimmt: C₉H₁₁N₃S₂, monoklin, P2₁/c,Z=4,a=6,000 (1) Å,b=8,840 (1) Å,c=21,452 (1) Å, =105,47 (1)^o,d _x=1,47 gcm^–3. Das Phasenproblem wurde mittels direkter Methoden gelöst und die Struktur bis zu einemR-Faktor vonR=0,047 verfeinert. Das Molekül ist im Kristall nahezu planar. Das Vorliegen schwacher intramolekularer Wasserstoffbrücken zwischen den beiden Thioamid-Stickstoffatomen und dem Pyridinstickstoff sowie intermolekularer Wasserstoffbrücken zwischen Thioamid-Stickstoff- und Thioamid-Schwefelatomen wird postuliert. IR- undRaman-Spektren vonPDTA und deuteriertemPDTA werden diskutiert.

     

Dichlorobis(cycloalkylamine)platinum(II) complexes structure activity relationship on the human MDA-MB-231 breast cancer cell line

Summary The syntheses of dichlorobis(cycloalkylamine)platinum(II) complexes withcis andtrans cycloalkylamine ligands [cis-PtCl₂(C₃H₅NH₂)₂ tocis-PtCl₂(C₈H₁₅NH₂)₂ (3–8) andtrans-PtCl₂(C₇H₁₃NH₂)₂ (9) andtrans-PtCl₂(C₈H₁₅NH₂)₂ (10)] are described. The distinction betweencis andtrans isomers was achieved by¹H-NMR spectroscopy. The antitumor activity was determined on the cell proliferation of the human MDA-MB-231 breast cancer cell line during long-term drug exposure. The complexes with small cycloalkylamine ligands (3–6) were inferior, those with large cycloalkylamine ligands were comparable (7) or superior (8) to cisplatin. Surprisingly, thecis/trans isomers7/9 and8/10 were equally active. All cycloalkylamine ligands were inactive. IR-spectroscopic studies showed that the size of the cycloalkylamine ring does not lead to significant differences in the Pt-Cl binding strength. Therefore it is assumed that the markedly stronger antitumor activity of the higher homologues,7–10, is not the result of a faster reaction with bionucleophils such as DNA. A possible explanation of the high activity of7–10 is the strong lipophilicity of the complexes. This assumption was confirmed by toxicity tests against confluent cultures.In memory of Professor Dr. Günter Gliemann, late director of the Institut für Physikalische und Theoretische Chemie, Universität Regensburg.     

Reaktion von 2-(N-Alkyl-p-hydroxyanilino)-1,4-benzochinonen Diazomethan. N-(Alkyl-p-hydroxyanilino)-4,7-indazolchinone und ihre isomeren N-Methylderivate

The reaction of N-alkyl-p-hydroxyanilinobenzoquinones1 a–d, its acetylderivatives1 ₁–c₁ and the methoxyderivative1 a₂ with diazomethan yields in dependence on the reaction-conditions the indazolquinones2 a–d, 2 a₁–c₁ or2a ₂, the1-methylindazolquinones3 a–d and3 ₁–c₁, and finally the methoxy-1-methylindazolquinones5 a–d. The 2-methyl-isomeres6 a–d are formed only in small amounts. Methylation of2 a with dimethylsulfate gives5 a and6 a in the ratio of appr 2 to 1. Acetylation of2 a–d with acetanhydride leads to the N–O-acetylderivatives, which are easily hydrolyzed to2 a₁–d₁ during work up;3 a d yields3 a₁–d₁. The structures are established by the described crossexperiments and by spectroscopy (UV/VIS, IR, NMR).

Herrn Prof. Dr.G. Zigeuner zum 60. Geburtstag gewidmet.     

Reactions of isomeric 3,6- and 3,5-di-tert-butyl-ortho-benzoquinones with NH3

The interaction of 3,6-di-tert-butyl-ortho-benzoquinone (1) and 3,5-di-tert-butyl-ortho-benzoquinone (2) with NH₃ in water—alcohol medium and with (NH₄)₂CO₃ in a solid phase has been studied. Redox processes with participation of a nucleophile of the medium take place for1, while2 reacts with NH₃ at the carbonyl group with transformation of the quinone imide. The mechanism of redox transformation of1 has been proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1789–1793, September, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No. 94-03-08653).     

Triterpene Glycosides from Cussonia paniculata. I. Isolation and Structure Determination of Glycosides A, B1, B2, C, D, G2, H1, and H2 from Leaves of Cussonia paniculata

The 3-O-β-D-glucopyranoside of β-sitosterol (1) and the known triterpene glycosides 3-O-α-L-arabinopyranosides of oleanolic (2a) and ursolic (2b) acids and hederagenin (3), 3-O-β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosideofoleanolic acid (4), 3-O-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosides of oleanolic (5a) and ursolic (5b) acids and the newglycoside 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranoside of 23-hydroxyursolic acid (6) were isolated from leaves of Cussonia paniculata (Araliaceae). Their structures were established using chemical methods and NMR spectroscopy.__________Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 160–163, March–April, 2005.     

Yttrium complexes derived from 5,11,17,23-tetra-tert-butyl-25,27-dihydroxy-26,28-dimethoxycalix[4]arene (LH2). Synthesis,properties, and structures of the [LY(thf)(μ-Cl)]2 and [LY(thf)3]+[L2Y]– complexes

5,11,17,23-Tetra-tert-butyl-25,27-dihydroxy-26,28-dimethoxycalix[4]arene (1, LH₂) was deprotonated with two equivalents of potassium naphthalenide in THF at room temperature. The reaction of a dipotassium derivative of 1 prepared in situ with anhydrous YCl₃ in a THF medium afforded the corresponding yttrium alkoxychloride [LY(thf)(-Cl)]₂·4thf (2·4thf) in 71% yield. According to the X-ray diffraction data, complex 2 has a dimeric structure. The reaction of equimolar amounts of [(Me₃Si)₂N]₃Y and compound 1 in a THF—toluene mixture at 60 °C was accompanied by the complete replacement of the bis(trimethylsilyl)amide ligands to form the homoligand ionic complex [LY(thf)₃]⁺[L₂Y]^– (3). The structure of the latter was established by X-ray diffraction analysis.     

Reductivetrans-2,6-diallylation of pyridines with allylboranes. Synthesis oftrans- andcis-2,6-diallyl-1,2,5,6-tetrahydropyridines and their deuterated derivatives

The reductivetrans-2,6-diallylation of pyridines with triallyl- and allyl(dialkyl)boranes has been discovered. Heating (40–100 °C) of pyridine, deuteropyridine, or 3-bromopyridine complexes with triallylborane in the presence of alcohols (ROH or CH₃OD), water, or Et₂NH results in the respectivetrans-2,6-diaIlyl-1,2,5,6-tetrahydropyridines (2,3,22, or25) in 20–97 % yields. A preparative method for the isomerization oftrans-2,6-diallyl compounds2 and25 into the respectivecis-isomers4 and28 by heating them with triallyl- or allyl(dialkyl)boranes (125–150 °C) has been suggested. The hydrogenation oftrans- orcis-2,6-diallyl-1,2,5,6-tetrahydropyridines gavetrans- orcis-2,6-dipropylpiperidines, respectively. Thecis- andtrans-configurations of compounds2 and4 were established by analyzing the NMR spectra ofN-benzyl (7 and13) andN,N-dimethyl (6 and 14) derivatives of piperidine derivatives5 and8. A possible mechanism for the reductive diallylation of pyridines has been discussed.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 693–704, April, 1994.This study was financially supported by the Russian Foundation for Basic Research (Project 93-03-18193).     

Synthesis of 4-thia analogues of isoquinoline alkaloids

Summary (±)-4-Thiacarnegin (3) was synthesized by reaction of 6,7-dimethoxy-3-methyl-2H-1,3-benzothiazinium iodide (2) with methyl magnesium iodide, thereby opening a new synthetic route to 4-substituted dihydro-2H-1,3-benzothiazines. Compound3 was also obtained by reduction of 6,7-dimethoxy-3,4-dimethyl-2H-1,3-benzothiazinium iodide (5). In a similar way, reduction of the quaternary salts9 a–c afforded the (±)-4-thia analogues of cryptostilin-I, -II and -III (10 a–c). The isomers of the former compounds (12 a–c) were also synthesized by reduction of the 4H-1,3-benzothiazinium salts11 a–c.

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Synthese von 4-Thiaanalogen von Alkaloiden mit Isochinolingerüst

Zusammenfassung Aus 6,7-Dimethoxy-3-methyl-2H-1,3-benzothiaziniumjodid (2) wurde mit Methylmagnesiumjodid (±)-Thiacarnegin (3) dargestellt. Diese Reaktion bietet ein neues Verfahren für die Synthese von 4-substituierten Dihydro-2H-1,3-benzothiazinen.3 wurde auch durch Reduktion von 6,7-Dimethoxy-3,4-dimethyl-2H-1,3-benzothiaziniumjodid (5) erhalten. Die Reduktion der quartären Ammoniumsalze9 a–c ergab ebenfalls die Cryptostillin I-, II-, III-(±)-4-thiaanalogen Verbindungen (10 a–c). Reduktion der 4H-1,3-Benzothiazinium-Salze11 a–c lieferte die entsprechenden Isomeren12 a–c der obengenannten Verbindungen.

     

Preparation and steric structure of 3(2H)-pyridazinones and 1,2-oxazin-6-ones fused with three- to six-membered saturated carbocycles or norbornane skeleton

Summary Reactions ofcis-2-(4-methylbenzoyl)-cyclopropane- (1) and-cyclobutanecarboxylic acids (2), the stereoisomeric cyclohexyl homologues (3 and4), and di-endo-3-(4-methylbenzoyl)-bi-cyclo-[2.2.1]heptane-2-carboxylic acid (5) with hydrazines yield the cycloalkane-condensed (3(2H)-pyridazinones6–9 and the norbornane di-endo-fused derivatives10. With hydroxylamine, compounds1 and3–5 were transformed to the cycloalkane- and norbornane-condensed 1,2-oxazin-6-ones11–14. Transformation of3–5 led to thetrans-hexahydroanthrone17a and its methylene-bridged analogue24. From the stereoisomeric hexahydro-1(3H)-isobenzofuranones20 and21, the partly saturated anthrones were also prepared; the products (16b and17b) contain the methyl substituent in position 6. On reduction,16b yield the 2-methyloctahydroanthracene22. The structures of the compounds were proved by¹H and¹³C NMR spectroscopy, making use of NOE, DEPT, and CH-COSY techniques.

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Synthese und räumliche Struktur von mit drei- bis sechsgliedrigen gesättigten Homocyclen oder Norbornan kondensierten 3(2H)-Pyridazinonen und 1,2-Oxazin-6-onen

Zusammenfassung Die Reaktion voncis-2-(4-methylbenzoyl)-cyclopropan-(1) und-cyclobutancarbonsäuren (2), der stereoisomeren cyclohexyl-Homologen (3 und4) und von di-endo-3-(4-methylbenzoyl)-bicyclo[2.2.1]heptan-2-carbonsäure (5) mit Hydrazinen ergibt die cycloalkankondensierten 3(2H)-Pyridazinone6–9 und das methylenüberbrückte di-endo-Derivat10. Die Verbindungen1 und3–5 wurden mit Hydroxylamin zu den cycloalkan- und norbornankondensierten 1,2-Oxazin-6-onen11–14 umgesetzt.3–6 reagierten zumtrans-Hexahydroanthron17a und seinem methylenüberbrückten Analogen24. Die teilweise gesättigten Anthrone wurden auch aus den stereoisomeren Hexahydro-1(3H)-isobenzofuranonen20 und21 hergestellt (16b und17b), wobei der Methylsubstituent jedoch in Position 6 lokalisiert ist. Reduktion von16b ergab das 2-Methyloctahydroanthracen22. Die Strukturen der Verbindungen wurden durch NMR-Spektroskopie abgesichert (¹H,¹³C, DEPT, CH-COSY, NOE).

     

Zur Kenntnis der Reaktionsfähigkeit des unsubstituierten Thiomorpholins und alkylsubstituierter Thiomorpholine. 3. Mitt

A new synthesis of thiomorpholine by ring closure of -chloro--aminodiethylene-sulfide with potassium hydroxide is reported. Numerous reactions of thiomorpholine (1) and, especially, 2-methyl-3-ethyl-thiomorpholine (2) are described such as acylation, diacylation (3–43), reactions with sulfonic acid chlorides (44–52), isocyanates (53–61, 70–75), diisocyanates (62–66, 76–78) and isothiocyanates (67–69, 79–82), alkylation reactions (83–111) and the synthesis of thiomorpholino-dithiocarbamates (112–121).

Teil der Dissertation,E. Wilms, Techn. Hochschule Aachen, 1971.     

The preparation,properties and gas-phase molecular structure of difluoro(germylthio)phosphine

Difluoro(germylthio)phosphine, PF₂(SGeH₃), has been prepared by the reaction of S(PF₂)₂ with GeH₃Cl, and has been characterised by i.r.,Raman, n.m.r. and mass spectroscopy. Cleavage reactions with Cl₂ and HBr, donor reactions of the phosphorus atom and exchange reactions with platinum complexes have been studied. The molecular structure of PF₂(SGeH₃) in the gas phase has been determined by electron diffraction. Principal parameters (r _a) are:r(Ge–S) 225.6(4)pm;r(P–S) 211.5(8)pm;r(P–F) 159.0(9)pm; <(GeSP) 99.0(6)° <(SPF) 99.9(4)° <(FPF) 97.0(10)°. The conformation adopted is such that there are short non-bonded F...H contacts, with the PF₂ group twisted 18° from the position in which the FPF angle bisector eclipses the Ge–S bond.

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Difluor(germylthio)phosphin. Darstellung, Eigenschaften und Molekülstruktur in der Gasphase

Zusammenfassung PF₂(SGeH₃) wurde über die Reaktion von S(PF₂)₂ mit GeH₃Cl dargestellt und mittels IR,Raman, NMR and MS charakterisiert. Es wurden Spaltungs-reaktionen mit Cl₂ und HBr, Donor-Reaktionen des Phosphor und Austausch-reaktionen mit Platinkomplexen untersucht. Die Molekülstruktur von PF₂(SGeH₃) in der Gasphase wurde mittels Elektronendiffraktion bestimmt. Die Hauptparameter (r _a) sind:r(Ge–S) 225,6(4)pm;r(P–S) 211,5(8)pm;r(P–F) 159,0(9)pm; <(GeSP) 99,0(6)° <(SPF) 99,9(4)° <(FPF) 97,0(10)°.

     

Molecular structure and decomposition mechanism of peracetic acid esters AcOOR (R = Me,Bu<Superscript>t</Superscript>)

The molecular structure and conformational mobility of methyl and tert-butyl esters of peracetic acid AcOOR (R = Me (1), Bu^t (2)) were studied by the ab initio MP4(SDQ)//MP2(FC)/6-31G(d,p) method and density functional B3LYP/6-31G(d,p) approach. The B3LYP calculated equilibrium conformations of the molecules are characterized by the C-O-O-C torsion angles of 93.6° (1) and 117.0° (2). Structural features of the molecules under study and a distortion of tetrahedral bond configuration at the C_α atom were explained using the natural bonding orbital approach. The standard enthalpies of formation of AcOOMe (−328.5 kJ mol⁻¹) and AcOOBu^t (−440.4 kJ mol⁻¹) were determined using the G2 and G2(MP2) computational schemes and the isodesmic reaction approach. The transition state of AcOOMe decomposition into AcOOH and formaldehyde was calculated (E _a = 122.8 kJ mol⁻¹). The thermal effects of homolytic decomposition of the peroxy esters following a concerted mechanism (Me^· + CO₂ + ^·OR) and simple homolysis of the peroxide bond (AcO^· + ^·OR) were found to be 97.5±0.3 and 155.1±0.3 kJ mol⁻¹, respectively. At temperatures below 400 K, the most probable decomposition mechanism of peroxy esters 1 and 2 involves simple homolysis of the O-O bond.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2021–2027, October, 2004.     

Stereoselective formation of ansa-metallocenes in reactions of radical-anionic salts of acenaphthylene with lanthanide and calcium halides

ansa-Metallocenes (⁵:⁵-C₂₄H₁₆)M(THF)₂ (M = Sm (1), Yb (2), Ca (3)) and (⁵:⁵-C₂₄H₁₆)MI(THF) (M = Dy (8), Er (9), Tm (10), Lu (11)) were prepared in 50—90% yields by the in situ reactions of two equivalents of potassium acenaphthylenide K⁺C₁₂H₈ ^– with MI₂ or MI₃, respectively. Complexes 2 and 3 were also obtained by direct reduction of acenaphthylene with ytterbium and calcium naphthalenides, respectively. An ESR signal of the acenaphthylene radical anion, which was observed upon dissolution of compound 2 in THF, indicates that the [C₂₄H₁₆]^2– ansa-ligand dissociated into two [C₁₂H₈]^·– radical anions. Hydrolysis of complex 2 in benzene afforded 1,1",3,3"-tetrahydro-3,3"-biacenaphthylene (4) and 3,3",4,4"-tetrahydro-3,3"-biacenaphthylene (5). The reaction of complex 2 with ZrCl₄ and the reaction of compound 3 with Me₃SiCl proceeded with the cleavage of the C—C bond between two acenaphthylene fragments of the [C₂₄H₁₆]^2– ansa-ligand to produce (²-C₁₂H₈)ZrCl₂(THF)₃ (6) and bis(trimethylsilyl)acenaphthene (Me₃Si)₂C₁₂H₈ (7), respectively. Compounds 1—3, 6, 7, and 11 were characterized by ¹H and ¹³C NMR spectroscopy. The temperature dependence of the ¹H NMR spectrum of compound 11 in tetrahydrofuran is indicative of the dynamic exchange of the solvent molecules in the coordination sphere of the Lu atom. After cooling of the solution to 210 K, the dynamic process was terminated as evidenced by the nonequivalence of the ¹H signals of two acenaphthylene fragments. According to the X-ray diffraction data for complex 11, dimerization of two acenaphthylene radical anions at the Lu atom gave rise to the rac-ansa-metallocene structure. In compound 11, the Lu atom is ⁵-coordinated by two five-membered rings of the acenaphthylene ligands and also by the I atom and the THF molecule. The coordination environment about the Lu atom is a distorted tetrahedron. The average distance between the lutetium atom and the carbon atoms of the five-membered rings is 2.623 .     

Der Einfluß großer Salzkonzentrationen auf die Oxydationsreaktion von Fe(phen) 3 2+ mit Ce(IV) in Schwefelsäure

The influence of NaClO₄, NaCl and Na₂SO₄ on the oxidation of Fe(phen) ₃ ²⁺ by Ce(IV) was investigated by means of the stopped-flow method. At the concentrations range of NaClO₄ and NaCl 0.1–1.0M the rate constant values decrease from 1.03·10⁵ to 0.56·10⁵M^–1s^–1 and from 1.08·10⁵ to 0.81·10⁵M^–1s^–1 respectively.In varying concentrations of Na₂SO₄ solutions (0.05–0.35M) the rate constant values decrease from 1.05·10⁵M^–1s^–1 to 0.45·10⁵M^–1s^–1.Taking into account the negative salt effect the mechanism of the reaction progress is proposed.

     

Chromium(III) Hydroxide Solubility in The Aqueous Na+-OH?-H2PO?4-HPO2?4-PO3?4-H2O System: A Thermodynamic Model

Chromium(III)-phosphate reactions are expected to be important in managing high-level radioactive wastes stored in tanks at many DOE sites. Extensive studies on the solubility of amorphous Cr(III) solids in a wide range of pH (2.8–14) and phosphate concentrations (10^–4 to 1.0 m) at room temperature (22±2)°C were carried out to obtain reliable thermodynamic data for important Cr(III)-phosphate reactions. A combination of techniques (XRD, XANES, EXAFS, Raman spectroscopy, total chemical composition, and thermodynamic analyses of solubility data) was used to characterize solid and aqueous species. Contrary to the data recently reported in the literature,⁽¹⁾ only a limited number of aqueous species [Cr(OH)₃H₂PO^–₄, Cr(OH)₃(H₂PO₄)^2–₂), and Cr(OH)₃HPO^2–₄] with up to about four orders of magnitude lower values for the formation constants of these species are required to explain Cr(III)-phosphate reactions in a wide range of pH and phosphate concentrations. The log K^o values of reactions involving these species [Cr(OH)₃(aq)+H₂PO^–₄&#x21CC;Cr(OH)₃H₂PO^–₄; Cr(OH)₃(aq)+2H₂PO^–₄&#x21CC;Cr(OH)₃(H₂PO₄)^2–₂; Cr(OH)₃(aq)+HPO^2–₄&#x21CC;Cr(OH)₃HPO^2–₄] were found to be 2.78±0.3, 3.48±0.3, and 1.97±0.3, respectively.     

Transformations of the chiral diphosphine rhodium catalyst [(1,5-COD)Rh(—)R,R-DIOP]+CF3SO3– under conditions of hydrogenation

Transformation products of the cationic rhodium complex [(1,5-COD)Rh(—)R,R-DIOP]⁺CF₃SO₃ ^– (1) (COD is cycloocta-1,5-diene and DIOP is (±)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane), which were obtained in its reactions with molecular hydrogen, base (NEt₃), and solvents in the absence of a substrate, were investigated by ¹H and ³¹P NMR spectroscopy. The solvate complexes [(Solv)₂Rh(—)R,R-DIOP]⁺CF₃SO₃ ^–, which were generated from complex 1 in its reaction with molecular hydrogen, underwent destruction of the diphosphine ligand with elimination of benzene and were subjected to oxidation by traces of moisture and oxygen to form the DIOP dioxide complex with Rh^I. In the absence of hydrogen, complex 1 in solutions produced the diphosphine dioxide rhodium(i) complex and mono- and binuclear rhodium(i) solvate complexes. The scheme of deactivation of the complex in the absence of the substrate was proposed. The catalytic activity of the solvate complexes [(ArH)Rh(—)R,R-DIOP]⁺CF₃SO₃ ^–, which contain benzene, p-xylene, and mesitylene in the coordination sphere, was studied in hydrogenation of Z--acetamidocinnamic acid.     

Zur Umsetzung von 8a-Methoxy-3,4-dihydro-2H-1,4-benzoxazin-6(8aH)-onen mit Diazoalkanen, 2. Mitt.

Summary 8a-Methoxy-3,4-dihydro-2H-1,4-benzoxazin-6(8aH)-ones2 undergo regio- and stereospecific 1,3-dipolar cycloaddition reactions with diazomethane or diazoethane to yield 3,4,6a,9,9a,9b-hexahydro-pyrazolo[3,4-h][1,4]benzoxazin-6(2H)-ones3, which slowly isomerize in solution to give the 3,4,8,9,9a,9b-hexahydro-pyrazolo[3,4-h][1,4]benzoxazin-6(2H)-ones5. The carbon of the diazoalkane dipole is attached to carbon C-8 of the benzoxazinone. The structures of the obtained products were determined by¹H- and¹³C-NMR spectroscopy. An X-ray crystal structure analysis of3 a was carried out at room temperature:C₁₁H₁₅N₃O₃,M _r =237.26, orthorhombic, Pc2₁n,a=9.173 (5),b=9.133 (4),c=13.281 (6),V=1112.6 (9) ų,Z=4,d _x =1.416 g/cm^–3, =0.93 cm^–1,R=4.33%,R _w =3.95% (919 observations, 168 parameters).

Herrn Prof. Dr. W. Fleischhacker zum 60. Geburtstag gewidmet     

Synthesis of the grapevine moth sex pheromone by Grignard—Schlosser cross-coupling: The effect of the electrophile structure on the stereoisomeric ratio in the reaction products

1-Acetoxy-2E,4Z-heptadiene (4) and 1-bromo-3E,5Z-octadiene (5) were obtained with 90 and 88–92 % configurational purity, respectively, starting from 2,4-heptadiyn-1-ol or 3,5-octadiyn-1-ol. The Li₂CuCl₄-catalyzed cross-coupling of the allylic acetate4 with 5tert-butoxypentylmagnesium chloride affords 1-tert-butoxy-7E,9Z-dodecadiene (11) contaminated with 25 % of minor stereoisomers in 54–60 % overall yield. Under similar conditions, the homoallylic bromide5 reacts with 4-tert-butoxybutylmagnesium chloride to give in 50–52 % yield another sample of diene11 containing 17 % of minor stereoisomers. If the latter coupling is carried out with enyne8 instead of5 followed bycis-hydrogenation of the triple bond in the resulting product, the configurational purity of diene11 is as high as 84.7 % (45 % overall yield). The reaction of11 with Ac₂O in the presence of FeCl₃ leads directly to the target 7E,9Z-dodecadienyl acetate (1) with somewhat lower configurational purity than that of the starting ether11.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1133–1137, June, 1993.