Tandem nitroaldol-dehydration reactions employing the dianion of phenylsulfonylnitromethane(1)

Reaction of phenylsulfonylnitromethane (1) with more than 2 molar equiv of LDA afforded the dilithium salt of phenylsulfonylnitromethane. Condensation of this dilithium salt with unbranched aldehydes occurred readily, but the initial nitroaldols dehydrated to afford unconjugated beta,gamma-unsaturated alpha-nitrosulfones in 52-88% yield. Evidence is presented that the beta,gamma-unsaturated alpha-nitrosulfones can equilibrate with the conjugated alpha,beta-unsaturated alpha-nitrosulfones at neutral pH. The normally disfavored alpha,beta-unsaturated alpha-nitrosulfones have been implicated in the formation of bis(alpha-nitrosulfones), Michael adducts of phenylsulfonylnitromethane. Three diastereomers (1R,2s,3S, 1R,2r,3S, and 1R,3R/1S,3S) have been identified for the bis(alpha-nitrosulfones) obtained in these reactions. In the case of acetaldehyde, condensation with the dilithium salt of phenylsulfonylnitromethane afforded only bis(alpha-nitrosulfones). The main product (three diastereomers) was the bis(alpha-nitrosulfone) derived from Michael addition of phenylsulfonylnitromethane and a minor product was tentatively identified as the bis(alpha-nitrosulfone) derived from dimerization. Also formed in the reaction of propanal with the dilithium salt of phenylsulfonylnitromethane was an unstable beta-amine, the formal conjugate addition product of diisopropylamine to the alpha, beta-unsaturated alpha-nitrosulfone. When tandem nitroaldol/dehydration reactions were carried out in the presence of thiols, the alpha,beta-unsaturated alpha-nitrosulfones were intercepted to provide beta-sulfides, the products of conjugate addition, in 61-83% yield.     

Synthesis and antitumor properties of N1-acyloxymethyl derivatives of bis(2,6-dioxopiperazines)

Many N1-acyloxymethyl derivatives VI of bis(2,6-dioxopiperazine) I, ICRF-154, were prepared and tested for antitumor activity. The treatment of I with formaldehyde gave a crystalline bis(N1-hydroxymethyl) derivative VII, which was acylated under various conditions to give bis(N1-acyloxymethyl) derivatives VI. Antitumor activity of VI against P388 leukemia in mice was studied. Several bis(N1-acyloxymethyl) compounds such as phenylacetyloxymethyl VI-6, methoxycarbonyloxymethyl VI-41, isobutoxycarbonyloxymethyl VI-44, and furancarboxymethyl VI-38 compounds were found to have potent antitumor activities. On the other hand, water-soluble esters having an amine or a carboxylic acid function in their acyl groups showed rather reduced activity. These bis(N1-acyloxymethyl) derivatives VI were presumably hydrolyzed into the parent bis(2,6-dioxopiperazine) I by nonspecific esterase in the body to exhibit their antitumor activity.     

Kristallstrukturen und spektroskopische Eigenschaften von 2λ3‐Phospha‐1, 3‐dionaten und 1, 3‐Dionaten des Calciums ‐ ein Vergleich am Beispiel der 1, 3‐Diphenyl‐ und 1, 3‐Di(tert‐butyl)‐Derivate

Crystal Structures and Spectroscopic Properties of 2λ³‐Phospha‐1, 3‐dionates and 1, 3‐Dionates of Calcium ‐ Comparative Studies on the 1, 3‐Diphenyl and 1, 3‐Di(tert‐butyl) Derivatives A hydrogen‐metal exchange between dibenzoylphosphane and calcium carbide in tetrahydrofuran (THF) followed by addition of the ligand 1, 3, 5‐trimethyl‐1, 3, 5‐triazinane (TMTA) furnishes the binuclear complex bis[(tmta‐N, N′, N″)calcium bis(dibenzoylphosphanide)] ( 1a ) co‐crystallizing with benzene. Similarly, reaction of bis(2, 2‐dimethylpropionyl)phosphane with bis(thf‐O)calcium bis[bis(trimethylsilyl)amide] in 1, 2‐dimethoxyethane (DME) gives bis(dme‐O, O′)calcium bis[bis(2, 2‐dimethylpropionyl)phosphanide] ( 1b ) in high yield. The carbon analogues 1, 3‐diphenylpropane‐1, 3‐dione (dibenzoylmethane) or 2, 2, 6, 6‐tetramethylheptane‐3, 5‐dione (dipivaloylmethane) and bis(thf‐O)calcium bis[tris(trimethylsilylmethyl)zincate] in DME afford bis(dme‐O, O′)calcium bis(dibenzoylmethanide) ( 2a ) and the binuclear complex (μ‐dme‐O, O′)bis[(dme‐O, O′)calcium bis(dipivaloylmethanide)] ( 2b ), respectively. Dialkylzinc formed during the metalation reaction shows no reactivity towards the 1, 3‐dionates 2a and 2b . Finally, from the reaction of the unsymmetrically substituted ligand 2‐(methoxycarbonyl)cyclopentanone and bis(thf‐O)calcium bis[bis(trimethylsilyl)amide] in toluene, the trinuclear complex 3 is obtained, co‐crystallizing with THF. The β‐ketoester anion bridges solely via the cyclopentanone unit.     

A palladium-catalyzed rearrangement of 1-vinyl-1-cyclobutanols

2-methyl-2-cyclopentene-1-ones are produced by treating 1-vinyl-1-cyclobutanols with bis(benzonitrile)palladium dichloride and benzoquinone in THF.     

Hydrolysis of Bis[5,5-dimethyl-3-(4-oxa-1-azoniacyclohexylidene)-1-cyclohexenyl] Sulfide Diperchlorate

Hydrolysis of bis[5,5-dimethyl-3-(4-oxa-1-azoniacyclohexylidene)-1-cyclohexenyl] sulfide diperchlorate, as well as of bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide, in the system MeCN-Et₃N yields a mixture of bis(5,5-dimethyl-3-oxo-1-cyclohexenyl) sulfide and isomeric 5,5-dimethyl-3-oxo-1-cyclohexenyl 3,3-dimethyl-5-oxo-1-cyclohexenyl sulfide. The structure of the products and their ratio were established by ¹H and ¹³C NMR and IR spectroscopy.     

Borchelate und Bormetallchelate,V1

Substitution of only one bridged hydrogen atom of bis(1,2-cycloheptanedionedioximato)nickel(II) by the diphenylboron group is easily accomplished with formation of1. Both hydroxy groups of bis(dihydroxyboron-diaminoglyoximato)nickel(II) chelate² can be esterified by phenol or methanol (chelates2 a andb). The bis(diphenylboron) chelate3 a results from the reaction of bis(dihydroxyborondiaminoglyoximato)nickel(II) with diphenylboric anhydride. In the same way the corresponding chelates3 b-f are obtainable from the boron-free nickel chelates. The i.r. and u.v. spectra as well as the diamagnetic character of the compounds described are in agreement with planar structures.

IV. Mitt.:E. Hohaus, Mh. Chem., im Druck.     

Approaches to the Synthesis of Dicarboxylic Derivatives of Bis(pyrazol-1-yl)alkanes

Carboxylation of bis(pyrazol-1-yl)alkanes by oxalyl chloride was studied. It was found that 4,4′-dicarboxylic derivatives of substrates with electron-donating methyl groups and short linkers (from one to three methylene groups) can be prepared using this method. Longer linkers lead to significantly lower product yields, which is probably due to instability of the intermediate acid chlorides that are initially formed in the reaction with oxalyl chloride. Thus, bis(pyrazol-1-yl)methane gave only monocarboxylic derivative even with a large excess of oxalyl chloride and prolonged reaction duration. An alternative approach involves the reaction of ethyl 4-pyrazolecarboxylates with dibromoalkanes in a superbasic medium (potassium hydroxide–dimethyl sulfoxide) and is suitable for the preparation of bis(4-carboxypyrazol-1-yl)alkanes with both short and long linkers independent of substitution in positions 3 and 5 of pyrazole rings. The obtained dicarboxylic acids are interesting as potential building blocks for metal-organic frameworks.     

Copper(II) and nickel(II) complexes of the bis{N(3)-substituted thiosemicarbazones} of phenylglyoxal and 1-phenylpropane-1,2-dione

Copper(II) and nickel(II) complexes of phenylglyoxal and phenylpropane-1,2-dione bis{N(3)-methyl-, bis{N(3)-dimethyl-, bis{piperidylthiosemicarbazone} have been prepared and studied spectroscopically. The six bis(thiosemicarbazones) have been characterized by their melting points, as well as i.r., electronic and 1H-n.m.r. spectra. The four-coordinate copper(II) complexes have been studied by e.s.r. spectroscopy, and the copper(II) and nickel(II) complexes by spectroscopic techniques mentioned above. Upon formation of these complexes, the loss of protons from each thiosemicarbazone moiety occurs, and the bis(thiosemicarbazones) coordinate to the metal centres as dianionic, tetradentate N2S2 ligands.     

Regioselective 1–4 addition of acyl and equivalents to α-enones

2-lithio-1,3-dithianes, bis(phenylthio)alkyllithiums and bis(methylseleno)alkyllithiums add 1–4 to α-enones if HMPT is present in the medium prior to the addition of enones. Most of the reactions occur under kinetic control.     

1,7-Dithioxo systems. Reaction of bis(5,5-dimethyl-3-thioxo-cyclohex-1-en-1-yl) sulfide with amines

Reactions of amines (N,N-dimethylethane-1,2-diamine, benzylamine, aniline) with bis(5,5-dimethyl-3-thioxocyclohex-1-en-1-yl) sulfide result in cleavage of the sulfide bond and formation of the corresponding 3-amino-5,5-dimethylcyclohex-2-ene-1-thiones. Aminolysis of bis(5,5-dimethyl-3-oxocyclohex-1-en-1-yl) sulfide occurs at the carbonyl groups with conservation of the divinyl sulfide fragment.     

Reaction of zinc enolates derived from 1-aryl-2,2-dibromoalkan-1-ones with tetramethyl 2,2′-(1,4-phenylenedimethylidene)dimalonate,dimethyl 3,3′-(1,4-phenylene)bis(2-cyanoacrylate), and 2,2′-(1,4-phenylenedimethylidene)-bis(malononitrile)

Zinc enolates derived from 1-aryl-2,2-dibromoalkanones reacted with tetramethyl 2,2′-(1,4-phenylenedimethylidene)dimalonate, dimethyl 3,3′-(1,4-phenylene)bis(2-cyanoacrylate), and 2,2′-(1,4-phenylenedimethylidene)bis(malononitrile) to give, respectively, tetramethyl 3,3′-(1,4-phenylene)bis(2-alkyl-2-aroylcyclopropane-1,1-dicarboxylates), dimethyl 3,3′-(1,4-phenylene)bis(2-alkyl-2-aroyl-1-cyanocyclopropane-1-carboxylates), and 3,3′-(1,4-phenylene)bis(2-alkyl-2-aroylcyclopropane-1,1-dicarbonitriles) as a single stereoisomer.     

(Benzimidazol-1-yl)methyl]benzamides as bifunctional reagents for reliable inorganic-organic supramolecular synthesis

A series of ligands that utilize five-membered N-heterocycles as coordination sites, and the self-complementarity of the carboxamide functionality, have been employed in the supramolecular synthesis of Ag(I)-based extended networks. The crystal structures of eight compounds are reported: bis[4-(2-methylbenzimidazol-1-yl)methylbenzamide]silver(I) tetrafluoroborate hydrate methanol, 1; bis[3-(2-methylbenzimidazol-1-yl)methylbenzamide]silver(I) tetrafluoroborate, 2; bis[4-(5,6-dimethylbenzimidazol-1-yl)methylbenzamide]silver(I) tetrafluoroborate, 3; bis[4-(2-methylbenzimidazol-1-yl)methylbenzamide]silver(I) hexafluoroarsenate methanol, 4; bis[3-(2-methylbenzimidazol-1-yl)methylbenzamide]silver(I) hexafluoroarsenate methanol(0.5), 5; bis[4-(5,6-dimethylbenzimidazol-1-yl) methylbenzamide]silver(I) hexafluoroarsenate, 6; bis[4-(2-methylbenzimidazol-1-yl)methylbenzamide]silver(I) hexafluoroantimonate, 7; and bis[3-(2-methylbenzimidazol-1-yl)methylbenzamide]silver(I) hexafluoroantimonate, 8. An analysis of motifs and structural patterns that result from the primary intermolecular interactions in these structures, reveals that this family of ligands is capable of providing quite reliable means for propagating the linear geometry of the complex ions into extended 1-D architectures via ligand-ligand, N-H...O, hydrogen-bond interactions.     

Synthesis of 3-R-Sulfanyl-5-amino-1-phenyl-1H-pyrazole-4-Carbonitriles

Russian Journal of Organic Chemistry - Previously unknown 3-R-sulfanyl-5-amino-1-phenyl-1H-pyrazole-4-carbonitriles were synthesized by reactions of 2-[bis(alkylsulfanyl)methylidene]malononitriles...     

Synthesis and structure of tetraphenylantimony 1-adamantanecarboxylate and triphenylantimony bis(1-adamantanecarboxylate)

Reaction of pentaphenylantimony with triphenylantimony bis(1-adamantylcarboxylate) yielded the solvate of tetraphenylantimony 1-adamantylcarboxylate with benzene. Triphenylantimony bis(1-adamantylcarboxylate) was prepared from triphenylantimony and 1-adamantylcarboxylic acid in the presence of hydrogen peroxide in ether. X-ray studies showed that in the first and in the second product antimony atom has the distorted trigonal bipyramide coordination (OSbO and CSbO trans-angles are 179.42° and 174.58°, respectively). Sb-O interatomic distances are 2.154 and 2.202 Å, respectively. The carbonyl group oxygen atom is coordinated with the central atom, Sb?O interatomic distances are 2.570 and 3.396 Å, respectively.     

Synthesis of ditopic ligands containing bis(1<Emphasis Type="Italic">H</Emphasis>-pyrazol-1-yl)-methane fragments

New approaches have been proposed for the synthesis of compounds containing two bis(1H-pyrazol-1-yl)methane fragments. Nucleophilic replacement of the halogen atoms in appropriate tetrabromo derivatives by pyrazoles in the superbasic system KOH-DMSO gave ditopic chelating ligands: 1,1,2,2-tetrakis(1H-pyrazol-1-yl)ethane, 1,4-bis[bis(1H-pyrazol-1-yl)methyl]benzene, and 1,4-bis[bis(3,5-dimethyl-1H-pyrazol-1-yl)methyl]benzene. 1,4-Bis[bis(1H-pyrazol-1-yl)methyl]benzene was also synthesized by reaction of 1H-pyrazole with terephthalaldehyde in the presence of thionyl chloride. 1,1,2,2-Tetrakis(1H-pyrazol-1-yl)ethane was converted into the corresponding tetraiodo and tetranitro derivatives.     

Synthesis and Characterization of Both Enantiomers of a Chiral C_(60) Derivative Bearing the 1, 1'-Binaphthyl Group

Followingthedevelopmentoffullerenefunctionalization',therehasbeenanincreasinginterestinthesynthesisofchiralfullerenederivativesfortheirpotentialapplicationintheareasofpharmaceuticalsandoptics'~'.Introductionofchiralityfromthechiralsubstituenttothefullerenecore3hasbeenestablishedtobeoneofthemostversatilemethodsforthechiralfullerenederivatives.Inthisway,chiralweresynthesizedbyVasellaetap.ThesynthesisandCDspectraoffullerene-peptideswerereportedbyPratoandco-workers',aswellasDiederich'sgroup'.Rec…     

Specific and selective reduction of aromatic nitrogen heterocycles with the bis-pyridine complexes of bis(1,4-dihydro-1-pyridyl)zinc and bis(1,4-dihydro-1-pyridyl)magnesium

Aromatic nitrogen heterocycles, e.g. quinoline, 2,2‘-bipyridyl and 1,10-phenanthroline, are reduced in a uniquely specific and selective way by the bispyridine complexes of bis(1,4-dihyro-1-pyridyl)zinc and bis(1,4-dihydro-1-pyridyl)magnesium. The reactions occur by hydrogen transfer from the metal-bound 1,4-dihydropyridyl moieties to the substrates and yield zinc or magnesium salts of the 1,4-dihydroazaaromatic derivatives. Upon hydrolysis, the 1,4-dihydroazaaromatic compounds are liberated from the metal ions. The isolation and purification of several of the (novel) reduced compounds, e.g. 1,4-dihydroquinoline and 1,4-dihydro-1,10-phenanthroline, are described.     

Synthesis,Application, and Properties of Bis(1H-azol-1-yl)methanimines

Russian Journal of Organic Chemistry - The review considers methods of preparation and application of bis(1H-azol-1-yl)methanimines that are imino analogs of 1,1′-carbonylbisazoles widely...     

桥连双-(三氮杂环壬烷)化合物的合成

利用无水碳酸钾作缩合剂,在精制乙腈中使N,N'-二对甲苯磺酰基-1,4,7-三氮杂环壬烷3与双溴甲基化合物4a-4c缩合得到N-对甲苯磺酰基取代的桥连双-(三氮杂环壬烷)5a-5c,经浓硫酸脱去氮原子上的保护基团得到桥连双-(三氮杂环壬烷)6a-6c。化合物5a-5c和6a-6c均经元素分析、IR、^1HNMR、^1^3CNMR、MS等测试手段证实其结构和组成。     

Oxidation of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) chalcogenides and use of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl)sulfone in heterocyclization with primary amines

Oxidation of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfide and selenide with hydrogen peroxide in chloroform/acetic acid or acetic acid affords previously unknown E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfoxide, selenoxide, and sulfone. The reaction of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfone with primary amines in ethanol in the presence of NaHCO₃ or Na₂CO₃ is found to lead not only to heterocyclization but also to alcoholysis of the chloromethylidene groups in the intermediate bis(chloromethylidene) derivatives of thiomorpholine‐1,1‐dioxides to afford N‐organyl‐2(E),6(E)‐bis(ethoxymethylidene) thiomorpholine‐1,1‐dioxides as final products.