Derivatives of 1,1,2,2-tetraaminoethane: I. Condensation of 1,2-diacetoxy-1,2-bis(acylamino)ethanes with nitrogen-containing nucleophiles

Reaction of 1,2-diacetoxy-1,2-bis(acylamino)ethanes with acetamide and urethane gave rise to 1,2-bis(acetylamino)-1,2-bis(acylamino)ethanes and 1,2-bis(acylamino)-1,2-bis(ethoxycarbonylamino)ethanes respectively. Condensation products were isolated of reactions between 1,2-diacetoxy-1,2-bis-(acylamino)ethanes with acetonitrile, diaminofurazan, and 4-phenylfurazan-3-ylamine.     

Reaction of perfluorinated 1-ethyl-, 1,1-diethyl-, and 1,2-diethylcyclobutabenzenes with pentafluorobenzene in SbF<Subscript>5</Subscript>

Perfluoro(1-ethyl-1,2-dihydrocyclobutabenzene) reacts with pentafluorobenzene in SbF5 to give perfluoro(1-ethyl-2-phenyl-1,2-dihydrocyclobutabenzene). Analogous reaction of a mixture of perfluoro(1,1-diethyl-1,2-dihydrocyclobutabenzene) and perfluoro(1,2-diethyl-1,2-dihydrocyclobutabenzene) leads to the formation (after hydrolysis of the reaction mixture) of perfluorinated 7-phenyl-8,8-diethylbicyclo[4.2.0]octa-1,4,6-trien-3-one, 1,1-diethyl-2-(4-oxocyclohexa-2,5-dienylidene)-1,2-dihydrocyclobutabenzene, and 2-(pent-2-en-3-yl)benzophenone (from the 1,1-isomer) and perfluorinated (E)-1,2-diethyl-1-phenyl-1,2-dihydrocyclobutabenzene, 7,8-diethyl-8-phenylbicyclo[4.2.0]octa-1,4,6-trien-3-one, and 1-[2-(1-phenylprop-1-en-1-yl)-phenyl]propan-1-one (from the 1,2-isomer).     

Mild template synthesis of copper(II)-containing macrocyclic compounds in the CuII–1,2-diaminoethanedithione-1,2–ethanedione-1,2 and CuII–1,2-diamino-ethanedithione-1,2–butanedione-2,3 triple systems into Cu2[Fe(CN)6]-gelatin-immobilized matrix implantates

The complexing processes in the Cu^II–1,2-diaminoethanedithione-1,2–ethanedione-1,2 and Cu^II–1,2-diaminoethanedithione-1,2–butanedione-2,3 triple systems occuring in the copper(II)hexacyanoferrate(II) gelatin-immobilized matrix in contact with aqueous alkaline solutions (pH~12) containing 1,2-diaminoethanedithione-1,2 and ethanedione-1,2 or butanedione-1,2 under room temperature, and between MCl₂, 1,2-diaminoethanedithione-1,2 and ethanedione-1,2 or butanedione-1,2 in the ethanol solutions, upon heating up to ~80 °C, have been studied. In both systems indicated, template synthesis occurs in the gelatin-immobililized matrix but does not occur in the ethanol solution. As a result of template synthesis, macrocyclic Cu^II chelates with 2,7-dithio-3,6-diazaoctadien-3,5-dithioamide-1,8 and its 4,5-dimethylsubstituted derivative are formed in the gelatin-immobililized matrix. 1,2-diaminoethanedithione-1,2 and ethanedione-1,2 or butanedione-2,3 are the ligand synthons in the processes indicated.     

Stereoselective synthesis of optically active disilanes and selective functionalization by the cleavage of silicon-naphthyl bonds with bromine

Optically active disilanes with one chiral silicon center, (R)-1,2-dimethyl-1-(naphth-1-yl)-1,2,2-triphenyldisilane and (R)-1,2,2-trimethyl-2-(4-methoxynaphth-1-yl)-1-(naphth-1-yl)-1-phenyldisilane, were obtained by the reaction of (S)-methyl(naphth-1-yl)phenylchlorosilane (> 99% ee) with methyldiphenylsilyllithium or by the reaction of methyldiphenylchlorosilane with optically active (S)-methyl(naphth-1-yl)phenylsilyllithium and by the reaction of (S)-methyl(naphth-1-yl)phenylchlorosilane (> 99% ee) with dimethyl(4-methoxynaphth-1-yl)silyllithium. Under the optimized conditions, the reactions proceeded with almost complete inversion for the cholorosilanes and retention for the silyl anions. Optically active disilanes with two chiral centers, (1R,2R)-1,2-dimethyl-1,2-di(naphth-1-yl)-1,2-diphenyldisilane and (1S,2S)-1,2-di(4-methoxynaphth-1-yl)-1,2-dimethyl-1,2-diphenyldisilane, were obtained in high optical purity by the reactions of corresponding optically active halogenosilanes (Cl or F) with optically active silyllithiums. The silicon-silicon bond and the silicon-naphthyl bond of (R)-1,1,2-trimethyl-1,2-di(naphth-1-yl)-2-phenyldisilane and (1R,2R)-1,2-dimethyl-1,2-di(naphth-1-yl)-1,2-diphenyldisilane were cleaved without selectivity on bromination. The silicon-(4-methoxynaphth-1-yl) bond of (R)-1,2,2-trimethyl-2-(4-methoxynaphth-1-yl)-1-(naphth-1-yl)-1-phenyldisilane was regiospecifically cleaved, followed by the stereoselective cleavage of the remaining chiral silicon-naphthyl bond (94% inversion). Although the silicon-(4-methoxynaphth-1-yl) bonds of (1S,2S)-1,2-di(4-methoxynaphth-1-yl)-1,2-dimethyl-1,2-diphenyldisilane (> 99% ee) were regioselectively cleaved without silicon-silicon bond scission, remarkable racemization could not be avoided during the one-pot reaction.     

Polymeric organosilicon system VIII. Synthesis of poly[(disilanylene)diethynylene] with highly conducting properties

The reaction of bis(trimethylsilyl)butadiyne with 2 equiv. of methyllithium, followed by 1,2-dichloro-1,2-dimethyldiphenyl- or 1,2-dichloro-1,2-diethyldimethyldisilane gives poly[(1,2-dimethyldiphenyldisilanylene)diethynylene] (II) or poly[(1,2- diethyldimethyldisilanylene)diethynylene] (III), respectively. Films of II and III become conducting when treated with SbF₅ vapor.     

Reaktion von Bis(methylzink)‐1,2‐dipyridyl‐1,2‐bis(tert‐butyldimethylsilylamido)ethan mit Triisopropylsilylphosphan und ‐arsan

Reaction of Bis(methylzinc)‐1,2‐dipyridyl‐1,2‐bis(tert‐butyldimethylsilylamido)ethane with Triisopropylsilylphosphane and ‐arsane The reaction of bis(methylzinc)‐1,2‐dipyridyl‐1,2‐bis(tert‐butyldimethylsilylamido)ethane ( 1 ) with triisopropylsilylphosphane gives the three‐nuclear complex [1,2‐dipyridyl‐1,2‐bis(tert‐butyldimethylsilylamido)ethane]trizinc‐bis(μ‐triisopropylsilylphosphanediide) ( 2 ). Two zinc atoms show the coordination number of four whereas the third metal center is located between the two phosphorus atoms with a bent P–Zn–P‐moiety. The reaction of 1 with triisopropylsilylarsane proceeds analoguesly, however, we were not able to isolate analytically pure [1,2‐dipyridyl‐1,2‐bis(tert‐butyldimethylsilylamido)ethane]trizinc‐bis(μ‐triisopropylsilylarsanediide) ( 3 ).     

Reactions of azoles with tetrachloro-1,2-difluoroethane and 1,2-dichlorodifluoroethylene

Tetrachloro-1,2-difluoroethane reacted with pyrazole and imidazole sodium salts to give mixtures of the corresponding N-(1,2,2-trichloro-1,2-difluoroethyl) derivatives and (E)-1,2-difluoro-1,2-dihetarylethenes. (E)-1,2-Difluoro-1,2-di(3,5-dimethyl-1H-pyrazol-1yl)ethene was also obtained as a result of replacement of chlorine atoms in 1,2-dichloro-1,2-difluoroethene. Analogous reaction with more nucleophilic imidazole involved replacement of not only chlorine but also fluorine atoms in 1,2-dichloro-1,2-difluoroethene, yielding tetraimidazolyl-substituted ethylene.     

Probing single-chain magnets in a family of linear chain compounds constructed by magnetically anisotropic metal-ions and cyclohexane-1,2-dicarboxylate analogues

Five new metal-carboxylate chain-based laminated compounds, namely, infinity2[FeII(e,e-trans-1,2-chdc)] (3) (1,2-chdc = cyclohexane-1,2-dicarboxylate), infinity2[NiII(mu-OH2)(e,a-cis-1,2-chdc)] (4), infinity2[CoII(mu-OH2)(1,2-chedc)] (5) (1,2-chedc = cyclohex-1-ene-1,2-dicarboxylate), infinity2[Co5II(mu3-OH)2(OH2)2(1,2-chedc)4] (6), and infinity2[CoII(4-Me-1,2-chdc)] (7) (4-Me-1,2-chdc = trans-4-methylcyclohexane-1,2-dicarboxylate) have been hydrothermally synthesized. In these series of magnetic chain-based compounds, 3 and 7 have the same dimeric paddle-wheel M(II)-carboxylate chain as the previously reported compound, infinity2[CoII(trans-1,2-chdc)] (2). However, compound 3 does not behave as a single-chain magnet (SCM) but simply an alternating ferro-antiferro magnetic chain. Compound 4 has the cis conformation of 1,2-chdc ligand, which leads to a uniform aqua-carboxylate-bridged Ni(II) chain. Such a Ni-O chain exhibits strong antiferromagnetic interactions, leading to a diamagnetic ground state. Compound 5 features a corner-sharing triangular chain, or delta-chain, which is part of a Kagom lattice. However, 5 does not exhibit a spin-frustrated effect but simply spin competition. Compound 6 has a unique pentanuclear CoII cluster, which is further connected by the syn-anti carboxylate into a chain structure. Compound 6 exhibits antiferromagnetic interactions among the Co(II) ions, and no SCM behavior is observed. These results might indicate that the dimeric paddle-wheel Co(II)-carboxylate chain is essential in obtaining SCM behavior in this family of compounds. Although 2 and 7 have very similar SCM behavior, alternating current magnetic studies show that 7 has a higher energy barrier than that of 2. Such behavior is probably caused by the larger anisotropic energy barrier in 7.     

The structures of five cyclic diketones isolated from coffee

Five cyclic diketones isolated from coffee oil (four of them isomeric) have been proved to be: (a) 3-methylcyclopentane-1,2-dione; (b) 3,4-dimethylcyclopentane-1,2-dione; (c) 3,5-dimethylcyclopentane-1,2-dione; (d) 3-ethylcyclopentane-1,2-dione; (e) 3-methylcyclohexane-1,2-dione. The structures of these compounds, postulated exclusively on the basis of spectroscopic data (U.V. I.R. and mass spectrometry), were confirmed by synthesis.     

Regiospecific synthesis of 3-substituted imidazo[1,2-a]pyridines,imidazo[1,2-a]pyrimidines,and imidazo[1,2-c]pyrimidine

3-Substituted imidazo[1,2-a]pyridines, imidazo[1,2-a]pyrimidines, and imidazo[1,2-c]pyrimidine were obtained regiospecifically in yields of 35-92% in one pot by reaction of 2-aminopyridines or 2-(or 4-)aminopyrimidines, respectively, with 1,2-bis(benzotriazolyl)-1,2-(dialkylamino)ethanes.     

Theoretical determination of chromophores in the chromogenic effects of aromatic neurotoxicants

We report the first computational study of the chromophores responsible for the chromogenic effects of aromatic neurotoxicants containing a 1,2-diacetyl moiety in their oxidation metabolites. A series of ab initio electronic structure calculations was performed on two representative aromatic compounds, 1,2-diacetylbenzene (1,2-DAB) and 1,2-diacetyl tetramethyl tetralin (1,2-DATT), the putative active metabolites of the neurotoxic aromatic hydrocarbon compounds 1,2-diethylbenzene (1,2-DEB) and acetyl ethyl tetramethyl tetralin (AETT), and on the products of their possible reactions with proteins that result in chromogenic effects. The electronic excitation energies determined by three different computational approaches were found to be consistent with each other. The calculated results are consistent with the conclusion/prediction that the chromogenic effects of 1,2-DAB (or 1,2-DEB) and 1,2-DATT (or AETT) could result from ninhydrin-like reactions, rather than the formation of pyrrole-like compounds. Our pK(a) calculations further indicate that the chromophore, i.e., the product of the ninhydrin-like reaction showing the blue color, is deprotonated in neutral aqueous solution. The corresponding protonated structure has a different color as it absorbs in the blue region of the visible spectrum, and its chromogenic contribution would be significant in solution at low pH.     

Mononuclear and dinuclear palladium and nickel complexes of phosphinimine-based tridentate ligands

The tridentate bis-phosphinimine ligands O(1,2-C(6)H(4)N=PPh(3))(2)1, HN(1,2-C(2)H(4)N=PR(3))(2) (R = Ph 2, iPr 3), MeN(1,2-C(2)H(4)N=PPh(3))(2)4 and HN(1,2-C(6)H(4)N=PPh(3))(2)5 were prepared. Employing these ligands, monometallic Pd and Ni complexes O(1,2-C(6)H(4)N=PPh(3))(2)PdCl(2)6, RN(1,2-CH(2)CH(2)N=PPh(3))(2)PdCl][Cl] (R = H 7, Me 8), [HN(1,2-CH(2)CH(2)N=PiPr(3))(2)PdCl][Cl] 9, [MeN(1,2-CH(2)CH(2)N=PPh(3))(2)PdCl][PF(6)] 10, [HN(1,2-CH(2)CH(2)N=PPh(3))(2)NiCl(2)] 11, [HN(1,2-CH(2)CH(2)N=PR(3))(2)NiCl][X] (X = Cl, R = iPr 12, X = PF(6), R = Ph 13, iPr 14), and [HN(1,2-C(6)H(4)N=PPh(3))(2)Ni(MeCN)(2)][BF(4)]Cl 15 were prepared and characterized. While the ether-bis-phosphinimine ligand 1 acts in a bidentate fashion to Pd, the amine-bis-phosphinimine ligands 2-5 act in a tridentate fashion, yielding monometallic complexes of varying geometries. In contrast, initial reaction of the amine-bis-phosphinimine ligands with base followed by treatment with NiCl(2)(DME), afforded the amide-bridged bimetallic complexes N(1,2-CH(2)CH(2)N=PR(3))(2)Ni(2)Cl(3) (R = Ph 16, iPr 17) and N(1,2-C(6)H(4)N=PPh(3))(2)Ni(2)Cl(3)18. The precise nature of a number of these complexes were crystallographically characterized.     

1,2-migration of 2'-oxoalkyl group and concomitant synthesis of 2-C-branched O-, S-glycosides and glycosyl azides via 1,2-cyclopropanated sugars

Treatment of 2'-oxoalkyl 2-O-Ms(Ts)-alpha-C-mannosides (4, 5, and 6) with base resulted in 1,2-cyclopropanation via an intramolecular SN2 reaction due to their 1,2-trans-diaxial configurations. The 1,2-cyclopropanated sugars (10 and 13) were reacted with various alcohols, thiols, and sodium azide to produce 2-C-branched O- and S-glycosides and glycosyl azides (11, 14-28) in good to excellent yields. In contrast, 1,2-cis 2'-oxoalkyl 2-O-Ms(Ts)-alpha-C-glucoside 9 formed an acyclic conjugated aldehyde (31) under basic conditions, which occurred by 1'-enolation followed by beta-elimination. An intramolecular Michael addition from 31 produced 2-O-Ms-beta-C-glucoside 30 as a major product. However, due to the electron-withdrawing effect exerted by 2-O-Ms compound 31 also undergoes a C2 epimerization to form 32. Thereafter, the intramolecular Michael addition led to the formation of both 1,2-trans 2'-oxoalkyl 2-O-Ms-alpha-C-mannoside 4 and its beta-anomer (33). Because beta-elimination/Michael addition and C2 epimerization are reversible reactions, equilibriums among 9, 31, 30, 32, 33, and 4 were established, which included the transformation of 1,2-cis C-glucoside 9 into 1,2-trans C-mannoside 4. The subsequent 1,2-cyclopropanation of 4 was an irreversible reaction yielding 1,2-cyclopropanated 10 and further conversion to 1,2-migration products (11 and 12).     

Synthesis of substituted disulfonyl-containing polycyclic azines with the bridgehead nitrogen atom. Effects of the structure of 3-substituted pyridinium ylides on the regioselectivity of their reactions with <Emphasis Type="Italic">E</Emphasis>-1,2-di(alkylsulfonyl)-1,2-dichloroethenes

Heating the substituted pyridinium and isoquinolinium salts with E-1,2-di(alkylsulfonyl)-1,2-dichloroethenes in either chloroform or acetone in the presence of three-fold excess of Et₃N gave high yields of substituted 1,2-di(alkylsulfonyl)indolizines and 1,2-di(alkylsulfonyl) pyrrolo[2,1-a]isoquinolines, respectively. Effects of the structure of 3-substituted pyridinium ylides on the regioselectivity of their reaction with E-1,2-di(alkylsulfonyl)-1,2-dichloroethenes were revealed. It was shown that the presence of electron-releasing and electron-withdrawing substituents in the pyridinium ylide favors the formation of 8-substituted and 6-substituted 1,2-(dialkylsulfonyl)indolizines, respectively.     

A novel synthesis of 5-acylaminooxazoles

1,2-Diacylamino-1,2-di(benzotriazol-1-yl)ethanes 2 , easily prepared from the condensation of 1,2-di(benzotriazol-1-yl)ethane-1,2-diol (1) and primary amides, were converted to 5-acylaminooxazoles in good to moderate yields via intramolecular cyclization upon treatment with sodium hydride.     

Blends of Polypropylene and Syndiotactic 1,2-Polybutadiene:Morphology,Crystallization Behaviors and Mechanical Properties

Morphologies,crystallization behavior and mechanical properties of polypropylene（PP）/syndiotactic 1,2-polybutadiene（s-1,2 PB）blends were investigated.Morphology observation shows the well dispersed domains of s-1,2 PB in PP matrix with the rather small domain sizes from 0.1 to 0.5μm when the s-1,2 PB content increases from 5%to 20%（mass fraction）in the blends,and the phase structure tends to become co-continuous as s-1,2 PB content further increases.Crystallization temperature（Tc）of PP component in the blends is fluctuated with the variation of s-1,2 PB content in the blends.Compatibilization,to some extent,between the two components is inferred from the examination of both morphology and crystallization behavior.Improvement of impact strength of PP toughened by s-1,2 PB becomes significant only in the case of s-1,2 PB content above 20%（mass fraction）.     

Chiral ligand exchange micellar electrokinetic chromatography using borate anion as a central ion

Three compounds having 1,2-diol structure (1-phenyl-1,2-ethanediol, 3-phenoxy-1,2-propanediol, and 3-benzyloxy-1,2-propanediol) were enantioseparated by ligand exchange MEKC using (5S)-pinanediol (SPD) as a chiral selector and borate anion as a central ion together with SDS. When (S)-1,2-propanediol, (S)-1,2,4-butanetriol, or (S)-3-tert-butylamino-1,2-propanediol were used as the chiral ligand instead of SPD, these three compounds were not enantioseparated. When borate was replaced with 2-aminoethane-1-sulfonate or N-cyclohexyl-3-aminopropanesulfonate, no chiral separation was achieved. Therefore, the hydrophobic interaction between the chiral selector and the chiral analytes within the transient diastereomeric complex may play an important role in the enantioseparation achieved by the proposed method.     

The synthesis of some ethyl 3-(1,2-dialkylhydrazino)propanoates and their cyclization to 1,2-dialkyl-3-yrazolidinones

The preparation of several ethyl 3-(1,2-dialkylhydrazino)propanoates (III) by the reaction of 1,2-dialkylhydrazines with acrylates is described. Compound III is accompanied by small amounts of the bis addition products (V) in the reactions of ethyl acrylate with a few of the hydrazines. Cyclization of III to 1,2-dialkyl-3-pyrazolidinones (IV) was achieved with sodium methoxide. 1,2-Dialkyl-5-methyl-3-pyrazolidinones were obtained directly from 1,2-dialkylhydrazines and ethyl crotonate. A procedure for the preparation of 1,2-di-(2-ethoxycarbonylethyl)hydrazines is also given.     

Reversible redox behavior between stannole dianion and bistannole-1,2-dianion

The reversible redox behavior between the stannole dianion and the bistannole-1,2-dianion is demonstrated. Reaction of the stannole dianion with oxygen (1 eq) gives the 1,2-bistannole-1,2-dianion which is a tin-analogue of the cyclopentadienyl anion in 94% yield. Reaction of the stannole dianion with ferrocenium tetrafluoroborate (1 eq) also gives the 1,2-dianion. The 1,2-bistannole-1,2-dianion has a nonaromatic nature as evidenced by X-ray and NMR analysis. Reduction of the 1,2-dianion with lithium gives the starting dianion.     

Polyfunctional macroheterocycles

The reaction of 1-[1,2-bis(carbomethoxy)ethyl]aziridine with ethane-1,2-dithiol leads to 1.8-bis[1,2-bis(carbomethoxy)ethylamino]-3,6-dithiaoctane. Condensation with phthalic and terephthalic acid dichloride gives 9,10-benzo-8, 11-dioxo-7,12-bis[1,2-bis(carbomethoxy)ethyl]-1,4-dithia-7,12-diazacyclotetradec-9-ene and 9,12-benzo-8,13-dioxo-7,14-bis[1,2-bis(carbomethoxy)ethyl]-1,4-dithia-7,14-diazacyclohexadeca-9,12-diene, respectively, while condensation with formaldehyde gives 7,9,18,20-tetrakis[1,2-bis(carbomethoxy)ethyl]-1,4,12,15-tetrathia-7,9,18.29-tetraazacyclodocosane. The corresponding disulfone is formed in the oxidation of 9,10-benzo-8,11-dioxo-7,12-bis[1,2-bis(carbomethoxy) ethyl]-1,4-dithia-7,12-diazacyclotetradec-9-ene with 30% hydrogen peroxide.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1563–1565, November, 1988.