On the Reaction of Triaryl Trithioarsenites, (ArS)3As,with Octasulfur

para‐Substituted with electron donating or electron withdrawing groups triphenyl trithioarsenites, (ArS)₃As, and octasulfur in refluxing carbon disulfide or chloroform do not give the triaryl tetrathioarsenates, (ArS)₃As=S, as was claimed in the literature for tris(4‐methylphenyl) tetrathioarsenate. In some cases oxidative decomposition to As₂O₃ and disulfides ArSSAr was found. When equivalent amounts of the same esters and octasulfur were heated at 105 or 150 °C no As^V compound was detected or isolated and again some esters decomposed to As₂O₃ and disulfides. These experiments demonstrated that the aromatic trithioarsenites do not react with octasulfur, probably because they cannot open the octasulfur ring. These esters in solution react with octasulfur in the presence of a catalytic (10—20 mol%) amount of triethylamine giving disulfides, As₂O₃ and colored solids which could not be characterized.     

Stability of Charge-Transfer Complexes of CS2 with PH3 and its derivatives: Ab initio MRSDCI/CASSCF Study

While trialkylamines and dialkyl(phenyl)amines do not react with CS₂ in the sense of an addition reaction, the analogous phosphines react smoothly. Attempts to interpret the reaction course on the basis of semiempirical, HF, MP2, and MP4 calculations of energy changes failed completely. To understand why Me₃P or Me₂PhP react so vigorously (liquid phase, 300 K) with CS₂, CASSCF and MRSDCI calculations must be carried out.     

Lignin-type, α,β-unsaturated aldehydes of lignin-type in organic solvents

A 1:1 reaction of [HO(CH₂)₃]₃P with 4-hydroxy-3-methoxy-cinnamaldehyde (coniferaldehyde) or 3,5-dimethoxy-4-hydroxycinnamaldehyde (sinapaldehyde) in acetone at room temperature affords phosphonium zwitterions of the type R₃P⁺CH(4-O^?-Ar)CH₂CHO; other phosphines [R = Et, n-Bu, (CH₂)₂CN, and p-Tol] do not react under the same conditions. In alcohols R??OH(D) [R?? = CD₃, Et, (CD₃)₂CD, s-Bu, HOCH₂CH₂], the above phosphines (except the cyano-derivative) and those where R = i-Pr, Cy, Me₂Ph, MePh₂ do react within an equilibrium established between the reactants and the zwitterion-hemiacetal products R₃P⁺CH(4-O^?-Ar)CH₂CH(OH)(OR??) that are formed as a mixture of two diastereomers. The nature of the phosphine and the alcohol affects the equilibrium and the diastereomeric ratio.     

2-Alkynylcyclopent-2-enols from 2-Alkynylcyclohex-2-enones via 1-Alkynyl-7-oxabicyclo[4.1.0]heptan-2-ones

2-Alkynylcyclohex-2-enones 1a–c and 2a–c react with H₂O₂/NaOH in MeOH to afford 1-alkynyl-7-oxabicyclo[4.1.0]heptan-2-ones 3a–c and 4a–c , respectively. The 3-unsubstituted bicyclic epoxy ketones 3a, 3b , and 4a, 4b react further with H₂O₂/NaOH, undergoing ring contraction and (formal) decarbonylation to give 2-alkynylcy-clopent-2-enols 5a, 5b , and 6a, 6b , respectively. Epoxy ketones 3 are also obtained under neutral conditions on irradiation (λ = 350 nm) of cyclohexenones 1 in air-saturated benzene solution. Similarly, under neutral conditions oxo-cycloalkenecarbonitriles 8 react (thermally) with H₂O₂ in MeCN to give the oxabicyclic carbonitriles 9 .     

Spectrophotometry Determination of Arsenic(III) and Antimony(III) by Means of Isonicotinoylhydrazones of 4-Dimethylaminobezaldehyde (4-Dbih) and 2-Hydroxynaphthaldehyde (2-Hnih)

Abstract

4-DBIH and 2-HNIH react with As(III) and Sb(III) respectively, in CH₃COOH medium to form colored complexes stable in presence of EDTA. As(III) and Sb(III) do not react with 2-HNIH and 4-DBIH respectively, and the Sb(III)-2-HNIH complex is extractable into isoamyl alcohol. These behaviours were used for the spectrophotometry determination of As (III) and Sb(III) in presence of several cations.     

NaBH4/Ac2O/DOWEX(R)50WX4: A Convenient System for Fast Preparation of gem‐Diacetates from Aldehydes

Reductive‐acylalation of aldehydes has been carried out by NaBH₄/Ac₂O/DOWEX(R)50WX4 system. A variety of aldehydes (1 mmol) have been reacted with Ac₂O (0.5 mL) and NaBH₄ (1 mmol) in the presence of DOWEX(R)50WX4 (0.5 g) for the preparation of their corresponding acylals within 1 min at room temperature with excellent yields of the products (90‐95%). Ketones do not react with this system.     

Some Novel Quinone-Type Compounds Containing Arylseleno Groups Derived from Tetrachloro-1, 4-Benzoquinone and 2, 3-Dichloro-1, 4-Naphthoquinone

Tetrachloro-1, 2-benzoquinone and 2, 3-dichloro-1, 4-naphthoquinone react with a series of aryl and alkyl selenolate, generated either by the reaction of Grignard reagents and selenium powder or by the reduction of diselenides with NaBH₄, to give 3, 6-diarylseleno-2, 5-dichloro-1, 4-benzoquinones 3 and 2, 3-diarylseleno-1, 4-naphthoquinones 4 in good yields.     

Dealkylation of 4-phosphorylated 5-alkoxypyrazoles: Easy synthetic access to P-chloro ylides

The chlorination of 5-alkoxypyrazoles containing bis-(dialkylamino)- or diphenylphosphino groups at the4-position afforded highly unstable chlorophosphoni-um chlorides that dealkylated giving chlorobis(di-alkylamino)- and chlorodiphenylphosphonium(3-methyl-5-oxo-1-phenyl-5H-pyrazol-4-yl)ides. The P-chloro ylides do not react with aromatic aldehydes, but chlorine atoms are easily substituted with OH, NH₂ ArNH, and Et₂N residues. They also exhibit basic properties and add hydrogen chloride with protonation at N-2. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:41–49, 1998     

Direct N-alkylation of carbonic acid amides by use of palladium catalyst complexes

Conclusions Aromatic amides react with butadiene in the presence of Pd(acac)₂-Ph₃P-AlEt₃ (1:3:4) in DMF, and aliphatic amides react with the diene in the presence of Pd(acac)₂-Ph₃P-CO₂-NH₂ (1:10:192:438) in N-methylpyrrolidone-2 to form primarily N-2,7-octadienylamides.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 821–828, April, 1988.     

Gas phase ion chemistry in germane/ammonia,methylgermane/ammonia,and methylgermane/phosphine

Gaseous mixtures of germane or methylgermane with ammonia and methylgermane with phosphine have been studied by ion trap mass spectrometry. Rate constants of reactions of the primary ions and of the most important secondary ion species are reported, together with the calculated collisional rate constants and efficiencies of reaction. The GeH_n⁺ (n = 0–3) ions, formed by electron ionization of both GeH₄ and CH₃GeH₃, react with ammonia yielding, among others, the GeH_n⁺ (n = 2–4) ion family, which, in a successive and slow reaction with NH₃, only give the unreactive ammonium ion. Also, the CH₃GeH_n⁺ (n = 1, 2) species do not form Ge–N bonds, whereas secondary ions of germane, such as Ge₂H₂⁺, produce species containing germanium and nitrogen together. In the CH₃GeH₃/PH₃ mixture a great number of ions are formed with rather high rate constants from primary ions of both reagent molecules and from phosphorus containing secondary ions. GePH_n⁺ (n = 2–4) ions further react with methylgermane leading to cluster ions with increasing size such as Ge₂PH_n⁺ and Ge₂CPH_n⁺. The experimental conditions favoring the chain propagation of ions containing Ge and N, or Ge and P, with or without C, important in the chemical vapor deposition of materials of interest in photovoltaic technology, are discussed.     

Cyclodisilazane Synthese,Substitution und Kopplung

Cyclodisilazanes Synthesis, Substitution, Coupling 1-Amino-3-fluoro-1,3-disilazanes react with n-butyllithium to give cyclodisilazanes. Metallization of the rings allows a stepwise substitution with silylgroups and ring coupling via silylgroups. Compound 14 is as well an endo- as exocyclic non symmetrically substituted cyclodisilazane. Ring cleavage occurs in the reaction of compound 4 with H₂O ( 17 ) or NH₃ ( 18 ).     

Reaction of 4-Nitrophthalonitrile with Carbonate,Nitrite, and Fluoride

In DMSO and DMF at elevated temperatures, KF, KNO₂, NaNO₂, K₂CO₃, and Na₂CO₃ react with 4-nitrophthalonitrile to form 4,4′-oxybis-(phthalonitrile) and, mostly, 4-hydroxyphthalonitrile. Formation ratios depend on reaction conditions. Intermediates are discussed.     

Zur Chemie des Bis(methylsulfonyl)-amins (Dimesylamins). IV. Synthese von N-Alkyldimesylaminen mit Tetra-n-butylammonium-dimesylaminid

Investigations on Bis(methylsulfonyl)-amine (Dimesylamine). IV. Synthesis of N-Alkyl-dimesylamines with Tetra-n-butylammonium Dimesylaminide Primary and secondary alkyl iodides, diiodomethane, and α,ω-diiodoalkanes I[CH₂]_nI with n > 2 react with [(C₄H₉)₄N]N(SO₂Me)₂ in boiling CHCl₃ to form the corresponding dimesylamino alkanes. By this procedure, the new compounds 3 — 9 , 11 , 13 and 14 were prepared. Addition of bromine to the allyl compound 9 affords 10 . Alkyl chlorides and bromides do not react under these conditions. Cyclohexyl and tert.-butyl iodide eliminate olefins. ICH₂CH₂I is decomposed, forming I₂. 1,2-Bis(dimesylamino)-ethane ( 12 ), however, is prepared from ICH₂CH₂I and (MeSO₂)₂NCl. The kinetics of the alkaline hydrolysis of MeN(SO₂Me)₂ ( 1 ) is investigated.     

Fluorinated pyridine derivatives: Part 1. The synthesis of some mono- and bis-quaternary pyridine salts of potential use in the treatment of nerve agent poisoning

Experiments were performed to determine whether F- and CF₃-substituted pyridines undergo quaternization with iodomethane (1:1 molar ratio in THF) and 1,3-diiodopropane (2:1 molar ratio in MeCN). 2-Fluoropyridine and 2-(trifluoromethyl)pyridine did not react with MeI even under prolonged reflux, while 3-fluoropyridine, 3,5-difluoropyridine, 3-(trifluoromethyl)pyridine and 4-(trifluoromethyl)pyridine gave methiodide salts in 28-72% yield. 2-Fluoropyridine did not react with I(CH₂)₃I, 3-fluoropyridine gave the bis-quaternary salt and 3,5-difluoropyridine yielded a mono-quaternary derivative. Both 3- and 4-(trifluoromethyl)pyridine furnished the bis-quaternary products in 53 and 55% yield, respectively. The bis-quaternary salts are potentially useful in the treatment of organophosphorus nerve agent poisoning.     

Die Tieftemperatur-Synthese von Oxidhalogeniden,YOX (X = Cl,Br, I), als Quelle der Verunreinigung von Yttriumtrihalogeniden,YX3, bei der Gewinnung nach der Ammoniumhalogenid-Methode. Die Analogie von YOCl und YSCl

Low-Temperature Synthesis of Oxyhalides, YOX (X = Cl, Br, I), as the Source of Impurity in the Preparation of Trihalides, YX₃, via the Ammonium Halide Route. Analogy of YOCl and YSCl Ammonium halides, NH₄X (X = Cl, Br, I), react with Y₂O₃ and Y₂S₃, respectively, at temperatures as low as 230=C (X = Cl), 280=C (Br), and 360=C (I) (molar ratio 12:1) to yield (NH₄)₃YX₆, NH₃, and H₂O (H₂S). The choice of smaller ratios than 12:1 (for example 2:1) results in the formation of oxyhalides, YOX, via the reaction of (NH₄)₃YX₆ with surplus Y₂O₃. This reaction is therefore the actual source of impurity of rare-earth trihalides in their preparation via the ammonium halide routes.     

Effect of the type of crystal lattice in nickel(II) and copper(II) macrocyclic carboxylates on absorption of copper amine complexes from solutions

We have established that crystalline nickel-containing metal–organic frameworks (MOFs) bind the complex [Cu(NH₃)₄](ClO₄)₂ from acetonitrile solutions and do not react with [Cu(en)₂](ClO₄)₂. The MOF/copper ammine complex ratio in the products after reaching saturation is determined by the crystal lattice structures of the compounds, and increases from 1.2 (one-dimensional coordination polymer, 1D CP) to 3.2 (2D CP)and 3.9 (ionic MOF) moles of copper ammine complex per formula unit of sorbent. We have shown that it is possible to convert the bound ammine complex to nanosized copper(II) sulfide by treatment with sodium sulfide.     

Reactions of halogenoquinolizinium bromides with aniline,isopropylamine and liquid ammonia

The reactions of quinolizinium bromide ( QB ) and its four monobromo derivatives with aniline, isopropylamine and liquid ammonia have been investigated. With aniline 2- and 4-bromo QB undergo substitution, whereas 1- and 3-bromo QB do not react at all. With liquid ammonia all bromo derivatives and the parent compound react with ring opening. This diversity in the reaction course is explained in terms of the HSAB principle. 2-BromoQB reacts with isopropylamine under formation of 2-isopropylamino QB . Two molecules of isopropylamine are involved in this substitution, as we isolated an intermediate: 1-isopropylamino-4(2-pyridyl)-3-isopropyliminio-1-butene bromide ( 13 ). The structure of the latter compound was confirmed by X-ray analysis.     

Organometallic Molybdenum(V) Complexes with Primary Phosphine Ligands. Syntheses,Spectroscopic Properties and Molecular Structures of [Cp°MoCl4(PH2R)] (R = But, 1‐Ad,Cy, Ph, 2, 4, 6‐Me3C6H2, 2, 4, 6‐Pri3C6H2, Cp° = C5EtMe4)

[Cp°MoCl₄] (Cp° = C₅EtMe₄) reacts with primary phosphines PH₂R to give the paramagnetic phosphine complexes [Cp°MoCl₄(PH₂R)] [Cp° = C₅EtMe₄, R = Bu^t ( 1 ), 1‐Ad (1‐Ad = 1‐adamantyl; 2 ), Cy ( 3 ), Ph ( 4 ), Mes (Mes = 2, 4, 6‐Me₃C₆H₂; 5 ), Tipp (Tipp = 2, 4, 6‐Prⁱ₃C₆H₂; 6 )]. 1 — 6 were characterized spectroscopically (IR, MS), and X‐ray crystal structures were determined for 1 — 4 and 6 . EPR investigations in liquid and frozen solution confirmed the presence of Mo^V species, and the data were used to analyze the spin‐density distribution in the first coordination sphere. Complexes 3 and 4 react with two equivalents of NEt₃ with formation of [Cp°MoCl₂(η³‐P₄Cy₄H)] ( 7 ) and [Cp°₂Mo₂(μ‐Cl)₂(μ‐P₄Ph₄)] ( 8 ), respectively, in low yield. Complexes 7 and 8 were characterized by X‐ray crystallography.     

New method of synthesis of 1,1-bis(trialkylsilyl)- and bis(trialkylgermyl)germacyclopenta-2,4-dienes

The reactions of 1,1-dichloro-2,3,4,5-tetraphenyl-1-germacyclopenta-2,4-diene (1), magnesium, and R₃ECl (E = Si, Ge) under mild conditions (20 °C, THF) gave 1,1-bis(trimethylsilyl)-2,3,4,5-tetraphenyl-1-germacyclopenta-2,-4-diene (2a) and 1,1-bis(triethylgermyl)-2,3,4,5-tetraphenyl-1-germacyclopenta-2,4-diene (2b) respectively. The reaction is versatile and applies to the compounds R₃ECl (E = Si, Ge) that do not react with magnesium.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2234–2236, October, 2004.     

(Perhalogenmethylthio)heterocyclen. X. Säurekatalysierte Substitutionen an (Perchlorfluormethylthio)pyrrolen und deren agrobiologische Wirkung

(Perhalomethylthio)heterocycles. X

1 IX. Mitt.: s. [1].

. Acid-catalyzed substitutions on (perchlorofluoromethylthio)pyrroles and their agro-biological activities In the presence of C₄F₉SO₃H the (perhalomethylthio)pyrroles 1a–c react with Cl_3?nF_nCSCl (n = 1–3) to give mixtures of the 2,5- and 2,4-disubstituted pyrroles 2a–f and 3a–h . 2a and 3a react with CF₃SCl (catalyst CF₃SO₃H) yielding 2,3,5-tris (trifloromethylthio)pyrrole ( 4a ), which under similar conditions reacts further to give 2,3,4,5-tetrakis (trifluoromethylthio)pyrrole ( 5 ). As a by-product during the conversion of 3a to 4a 2,3,4-tris (trifluoromethylthio)pyrrole ( 4b ) is formed. The pyrroles 2a , 4a and 5 form the mercury salts 6a–c ; compound 5 yields also a silver salt 7 . The ¹H- and ¹⁹F-NMR. spectra are discussed and the agro-biological properties of the compounds investigated.