Synthesis of 1,2-bis(1-boraadamant-2-yl)ethane derivatives. Crystal structure of the racemic form

Condensation of triallylborane with octa-1,7-diyne followed by treatment of the reaction mixture with methanol afforded a mixture of stereoisomeric 1,4-bis(3-methoxy-3-bora-bicyclo[3.3.1]non-6-en-7-yl)butanes (1a,b). Hydroboration of the latter with a solution of BH₃ in THF yielded the tetrahydrofuran complex of 1,2-bis(1-boraadamant-2-yl)ethane (2) as a mixture of diastereomers. Pure racemate (2a) was obtained by crystallization from the reaction mixture and it was converted into the pyridine complex of 1,2-bis(1-boraadamant-2-yl)ethane (3). The structure of the latter was established by X-ray diffraction analysis. Complex2a was converted into the corresponding racemic 1,2-bis(1-hydroxyadamant-2-yl)ethane (4a) by the carbonylation-oxidation reaction. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 501–505, March, 2000.     

Macrobicyclic aminals

The synthesis of Schiff base macrocycles in the absence of templating cations and in non-protic and non-coordinating solvent media is reported. The reaction of pyridine-2,6-dicarboxaldehyde with the diamines 1,2-bis(2-aminophenoxy) ethane and 1,4-bis(2-aminophenoxy) butane has been found to give the corresponding macrobicyclic aminals. The chemical properties of the aminals are reported together with a preliminary study of their metal complexation reactions. The X-ray crystal structure of the aminal derived from pyridine-2,6-dicarboxaldehyde and 1,2-bis(2-aminophenoxy) ethane has been determined and verifies the macrobicyclic nature of the product.This paper is dedicated to the memory of the late Dr C. J. Pedersen.     

Successive electron transfer reaction of the lithium salt of 5-methyl-5,10-dihydrophenazine anion with 4-nitrophenethyl bromide via 4-nitrostyrene

The reaction of lithium salt of 5-methyl-5,10-dihydrophenazine anion with 4-nitrophenethyl bromide in 1,2-dimethoxyethane gave unexpected compounds, 1,2-bis[5-(10-methyl-5,10-dihydrophenazinyl)]-1-(4-nitrophenyl)ethane and 1,4-bis(4-nitrophenyl)-1,4-bis[5-(10-methyl-5,10-dihydrophenazinyl)]butane, while the reaction in dimethyl sulfoxide brought about the formation of 5-methyl-10-(4-nitrophenethyl)-5,10-dihydrophenazine. The successive electron transfer mechanism is proposed for the former reaction via 4-nitrostyrene.     

Pd/Cu catalyzed homo-coupling reactions of 2-iodo-3-iodomethyl-1,4-diarylnaphthalene in the presence of arylacetylene

Palladium/CuI catalyzed reactions of 2-iodo-3-iodomethyl-1,4-diarylnaphthalenes in the presence of arylacetylenes produced the corresponding sp³-sp³ homo-coupling products 1,2-bis(3-iodonaphthalen-2-yl)ethane in moderate to good yields.     

Palladium-catalyzed asymmetric tandem allylic substitution using chiral 2-(phosphinophenyl)pyridine ligand

Palladium-catalyzed asymmetric tandem allylic substitution of (Z)-1,4-diacyloxy- and (Z)-1,4-bis(alkoxycarbonyloxy)-2-butene (2a-c) using 2-(phosphinophenyl)pyridine 1 as chiral ligand provided optically active six-membered 2-vinyl-1,4-diheterocyclic compounds with good to high enantioselectivity. For example, the reactions with catechol, 2-(benzylamino)phenol, or 1,2-bis(benzylamino)ethane as a nucleophile gave 2-vinyl-1,4-benzodioxane (71% ee), 4-benzyl-2-vinyl-1,4-benzoxazine (86% ee), and 1,4-dibenzyl-2-vinylpiperazine (86% ee), respectively.     

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.     

Synthesis of 1, 2-bis(b-amino-o-carboranyl)ethane and 1,4-bis(b-amino-o-carboranyl)benzene

Conclusions 1,2-Bis(B-amino-o-carboranyl)ethane and 1,4-bis(B-amino-o-carboranyl)benzene were synthesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1669–1670, July, 1976.     

Determination of technetium based on quenching of the fluorescence of some organic compounds,with application to vegetation

Technetium is an effective quencher of the fluorescence produced by 2,5-diphenyloxazole (PPO), 1,4-bis(4-methyl-5-phenyl-2-oxazolyl)benzene (POPOP) and 2,2′-pyridil [1,2-dioxo-1,2-bis(2-pyridyl)ethane]. Spectrofluorimetric procedures for 0.01–12 μg Tc ml^?1 with PPO and 0.1–12 μg ml^?1 with 2,2′-pyridil, and a spectrophotometric method for 1–15 μg ml^?1 are described. The distribution of technetium in vegetation is measured by applying the PPO method.     

The role of nickelole intermediates in the oligomerization of alkynes

Bis(triphenylphosphine)nickel(II) chloride reacts with E,E,-1,4-dilithio-1,2,3,4-tetraphenylbutadiene to yield a solution of a 2,3,4,5-tetraphenylnickelole complex. This compound reacts promptly with CO to yield tetracyclone, with dimethyl acetylenedicarboxylate to form dimethyl tetraphenylphthalate and catalytically with diphenylacetylene to form hexaphenylbenzene. A similar treatment of (1,2-bis(diphenylphosphino)ethane)nickel(II) chloride with the lithium reagent led to the isolation of (1,2-bis(diphenylphosphino)ethane)bis(2,3,4,5-tetraphenylnickelole), which likewise reacts with dimethyl acetylenedicarboxylate to yield dimethyl tetraphenylphthalate. These results support the interpretation that nickeloles are reactive intermediates in the cyclotrimerization of alkynes by nickel(0) catalysts.     

Production of alkane and cyclohexane derivatives with two heterocyclic substituents of the furan,pyrrole, and thiophene series

Heating 1,2,11,12-tetrachloro-2,11-bis(R-4,9-dodecanediones) and 1,4-bis(3-R-3,4-dichlorobutanoyl)cyclohexanes gave, respectively, 1,4-difuryl derivatives of butane and cyclohexane, while treatment of them with primary amines or phosphorus pentasulfide in DMF was used to synthesize dipyrryl and dithienyl compounds. 1-R-3-R¹-3,4-Dichlorobutanones react with ethylenediamine in aqueous alkali solutions to give 1,2-dipyrryl or monopyrryl derivatives of ethane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1185–1189, September, 1991.     

Tetradentate diamido-bis-sulfide ligands on the base of o-aminobenzenethiol and their complexation with NiII,CoII, CuII chlorides in DMF solution and on the gold electrode surface

A series of cyclic and acyclic diamido-bis-sulfide ligands were synthesized by N-acylation of 1,2-bis(2-aminophenylthio)ethane and 1,4-bis(2-aminophenylthio)butane with acetic, malonic, and 3,3′-dithiodipropionic acid chlorides or esters. The complexation of obtained ligands with Cu^II, Ni^II, and Co^II salts in solution and on the gold electrode surface was studied. The formation of complexes of these ligands with copper(II) chloride in DMF is irreversible and accompanied by deprotonation of the amide nitrogen atoms.     

Interconversion of host–guest components in supramolecular assemblies of polycarboxylic acids and reduced Schiff bases

Eight supramolecular assemblies of benzene-1,3,5-tricarboxylic acid (H₃BTC) and benzene-1,2,4,5-tetracarboxylic acid (H₄BTtC) with reduced Schiff base of flexible backbone having phenolic and pyridyl groups, i.e., 1,2-bis(2-hydroxybenzylamino)ethane, 1,3-bis(2-hydroxybenzylamino)propane, 1,4-bis(2-hydroxybenzylamino)butane and 1,4-bis(4-pyridinylmethylamino)butane have been constructed by proton transfer reaction. H₃BTC forms host–guest type assemblies with amines having phenolic functionality, while a layered structure was obtained with pyridyl functionalized amine. H₄BTtC also formed host–guest assemblies with the diamines where reduced Schiff base acts as host and acid moiety acts as the guest. Different conformations of the diamines were observed in these assemblies. Theoretical studies were performed to analyze the effect of varied chain lengths of diamines on hydrogen bond interaction energy of the adducts.     

Reactivity of Iminophosphoranes. Formation of the Piperazine Ring

Reaction of 3-azidopropyl methanesulfonate with triphenylphosphine produced the 1,4-bis(triphenyl-phosphino)piperazine 5 by intermolecular cyclization, instead of formation azidine derivatives by an intramolecular pathway. Structural formulation of 5 was achieved by both spectral and X-ray crystal analysis. Hydrolysis of 5 under basic condition gives piperazine, whereas reaction of lithium diphenylphosphide with 5 produced 1,2-bis(diphenyl-phosphino)ethane (dppe) exclusively.     

Planar Ni(II) 1,2-dithiolenes involving bidentate P-donor ligands

A series of planar Ni(II) dithiolenes derived of maleonitriledithiol (mnt), benzene-1,2-dithiol (bdt) and toluene-3,4-dithiol (tdt) with bidentate P,P-ligands (dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, dpppn = 1,5-bis(diphenylphosphino)pentane) of the [Ni(P,P)(dithiol)] type have been synthesized. The compounds have been characterized by elemental analysis, IR and electronic spectroscopies, magnetochemical, conductivity measurements and thermal analysis. Single crystal X-ray analysis of [Ni(dpppn)(mnt)] confirmed a planar geometry of NiP₂S₂ chromophore. Possible practical applications such as use of these compounds for vulcanization accelerators and their anticholinesterase activity were evaluated.     

The exchange of chloro and ethoxy groups upon the addition of dimethylchlorosilane to vinyldimethylethoxysilane

The addition of dimethylchlorosilane to vinyldimethylethoxysilane in the presence of chloroplatinic acid yielded 1,2-bis(dimethylchlorosilyl)ethane, 1-(dimethylchlorosilyl)-2-(dimethylethoxysilyl)ethane and 1,2-bis(dimethylethoxysilyl)ethane. The formation of three products is explained on the basis of chloro-ethoxy exchange reactions. Equilibration of the dimethylchlorosilane-vinyldimethylethoxysilane system was investigated using ¹H NMR and gas-liquid chromatography. The equilibrium constants indicated near random behavior for the substituent exchange.     

含1,2-双(3,5-二氧哌嗪-1)乙烷和(±)-1,2-双(3,5-二氧哌嗪-1)丙烷低聚物的合成

<正> 将低分子药物或有药理活性的基团,通过高分子化,所得的高分子药物,具有较高的为细胞吞噬或胞饮等活性,并期望它们在体内崩解缓释,与相应的低分子药物相比,可以发挥长效、低毒的优点。 1,2双-(3,5-二氧哌嗪-1)乙烷和(±)1,2双(3,5-二氧哌嗪-1)丙烷,是临床使用     

Screening hydrolysis products of sulfur mustard agents by high-performance liquid chromatography with inductively coupled plasma mass spectrometry detection

Sulfur mustard (HD), bis(2-chloroethyl)sulfide, is one of a class of mustard agents which are chemical warfare agents. The main chemical warfare hydrolysis degradation products of sulfur mustards are: thiodiglycol, bis(2-hydroxyethylthio)methane, 1,2-bis(2-hydroxyethylthio)ethane, 1,3-bis(2-hydroxyethylthio)propane, and 1,4-bis(2-hydroxyethylthio)butane. The aim of this study is to identify these five hydrolysis degradation products utilizing reversed-phase high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (ICP-MS) for element-specific sulfur detection using a collision/reaction cell and electrospray ionization mass spectrometry to confirm the identification. To date, this is the first study utilizing ICP-MS with ³²S element-specific detection for the analysis of vesicant chemical warfare agent degradation products.     

Polyimides containing oxyethylene units

Four aromatic dinitro compounds containing oxyethylene units 1,2-bis(4-nitrophenoxy)ethane, bis(2)-(4-nitrophenoxy)ethyl ether, 1,2-bis(2)-(4-nitrophenoxy)ethoxy)ethane, and bis(2-(2-(4-nitrophenoxy)ethoxy)ethyl) ether were prepared by an aromatic nucleophilic substitution reaction that involved 1-fluoro-4-nitrobenzene and the appropriate oxyethylene glycol. Each of the dinitro compounds could be reduced chemically or catalytically to produce the diamines 1,2-bis(4-aminophenoxy)ethane, bis(2-(4-amino-phenoxy)ethyl ether, 1,2-bis(2-(4-aminophenoxy)ethoxy)ethane, and bis(2-(2-(4-aminophenoxy)ethoxy)ethyl) ether. Polymerization of the diamines was carried out in m-cresol with toluene as an azeotroping agent. Polymides derived from 5,5′-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]bis-1,3-isobenzofuradione exhibited good solubility in chlorinated solvents, glass transition temperatures as low as 140°C, as evidenced by viscous flow, and good thermal stability; a 5% weight loss generally occured at greater than 450°C. Isothermal aging studies conducted at 600°F(315°C) for 200 h indicated that weight loss is directly related to oxyalkylene chain length–10% for the shortest and 50% for the longest chain.     

Periodic mesoporous organosilicas with multiple bridging groups and spherical morphology

Bi- and trifunctional periodic mesoporous organosilicas (PMOs) with phenylene, thiophene, and ethane bridging groups were synthesized using 1,2-bis(triethoxysilyl)ethane (BTEE), 1,4-bis(triethoxysilyl)benzene (BTEB), and 2,5-bis(triethoxysilyl)thiophene (BTET) organosilica precursors and a poly(ethylene oxide)-poly(D,L-lactic acid-co-glycolic acid)-poly(ethylene oxide) (PEO-PLGA-PEO) triblock copolymer template under low acidic conditions. The PMO samples with different concentrations of organic bridging groups were obtained in the form of spherical particles having average diameters of 2-3 mum and 2D hexagonal (p6m) mesostructure with pore diameters of 7.3-8.4 nm. The particle morphology and chemistry of pore walls were tailored using different mixtures of organosilica precursors. Adsorption and structural properties of the aforementioned PMOs have been studied by nitrogen adsorption and small-angle X-ray scattering, whereas their framework chemistry was quantitatively analyzed by solid-state 13C and 29Si MAS NMR.     

Synthesis of perhydro-1,2,5,6-tetrazocine and derivatives

Synthetic routes to the title compounds were explored. 1,2,5,6-Tetraacetylperhydro-1,2,5,6-tetrazocine ( 6 , 36%) was produced from ethylene glycol bis-p-toluenesulfonate and the potassium salt of 1,2-bis(N,N′ -diacetylhydrazino)ethane in refluxing mesitylene. Its acid-catalyzed hydrolysis led to perhydro-1,2,5,6-tetrazocine ( 9 ), an air-sensitive, crystalline solid, the first reported unsubstituted tetraazacyclooctane and the first example of an unsubstituted macrocycle incorporating two or more endocyclic hydrazino groups. 1,2-Bis(hydrazino)ethane ( 4 ) and diisobutyl oxalate in refluxing dimethylformamide gave 1,4-diamino-2,3-diketopiperazine ( 11 ) rather than 3,4-diketoperhydro-1,2,5,6-tetrazoeine ( 12 ). The acid-catalyzed reaction of benzil with 4 gave 3,4,7,8-tetraaza-1,2,9,10-tetraphenyl-2,8-dccadien-1,10-dione ( 20 ).