Synthesis of 2(5H)-Furanone Derivatives with Symmetrical and Unsymmetrical Bis-1,2,3-triazole Structure

The interesting bioactivities of 2(5H)-furanone, 1,2,3-triazole, and amino acid derivatives have promoted their combination into one multifunctional molecule. The symmetrical bis-1,2,3-triazoles and mono-1,2,3-triazoles with one free azide group are synthesized respectively by controlling the molar ratio of reactants, N-[5-alkoxy-2(5H)-furanonyl] amino acid propargyl ester and 1,4-diazidobutane. The unsymmetrical bis-1,2,3-triazoles are afforded by the subsequent reaction of mono-1,2,3-triazoles with other terminal alkynes with good to excellent yields in a short time under the same mild “click” reaction conditions. The 32 new compounds obtained in the reactions are characterized by Fourier transform infrared, ¹H NMR, ¹³C NMR, mass spectrometry, and elemental analysis. Because of the diversity of four or five basic units in molecule, this methodology provides easy access to different chiral 2(5H)-furanone compounds with polyheterocyclic structure, especially with unsymmetrical bis-1,2,3-triazole moiety. Importantly, a simple approach is provided for the synthesis of unsymmetrical bis-1,2,3-triazoles using common diazides.     

Synthesis and Biological Activity of Novel Symmetrical Bis-2-phenyliminothiazolidine Derivatives

A series of novel symmetrical bis-2-phenyliminothiazolidine derivatives were designed and synthesized. The structures of all the title compounds were characterized by ¹H NMR and, in some cases, by ¹³C NMR, IR, and high-resolution mass spectra. Herbicidal activities were examined, and some of these compounds showed selectively herbicidal activity against Triticum aestivum. The type of linker between the two 2-phenyliminothiazolidines was crucial for the biological activities.     

Synthesis of Symmetrical Bis-(2-chloro-1,3,2-benzodiazaphosphorinones) Hydrolysis and Fluorination of Selected Compounds

The series of symmetrical bis-amides 3 was formed by the reaction of N-methylisatoic anhydride ( 1 ), with the diamines 2 . Reaction of 3 with phosphorus trichloride led to the formation of the symmetrical bis-(1,3,2-benzodiazaphosphorinones) ( 4 ). 4 c , 4 d and 4 e were easily hydrolyzed in moist air, leading to the formation of 5 c , 5 d and 5 e . In the presence of triethylamine, 4 c , 4 d and 4 e were allowed to react with Et₃N · 3 HF to give the symmetrical bis-P–F derivatives 6 c , 6 d and 6 e , which could be readily oxidized by (NH₂)₂C(:O) · H₂O₂, leading to the formation of a series of P(:O)F compounds 7 c , 7 d and 7 e . All compounds were characterized unambiguously by ¹H, ¹³C, ¹⁹F, and ³¹P-NMR-spectroscopy, mass spectrometry, and elemental analysis. All the bis-amides and bis-(1,3,2-benzodiazaphosphorinones), except 4 b and 4 f , exist as single conformers in common solvents such as toluene, diethyl ether, dichloromethane or chloroform. For compound 6 c , a single crystal X-ray structure analysis was conducted. The molecule displays crystallographic inversion symmetry.     

Hypervalent and binuclear silicon and germanium derivatives from bis-(3,5-di-tert-butyl-2-phenol)-oxamide

The reactions of bis-(3,5-di-tert-butyl-2-phenol)oxamide (1) with Cl₂SiR₂ (Me or Ph) or Cl₂GeR₂ (Me, nBu or Ph) in THF provided binuclear pentacoordinated silicon and germanium compounds: bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-dimethylsilane (2), bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-diphenylsilane (3), bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-dimethylgermane (4), bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-di-n-butylgermane (5) and bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-diphenylgermane (6). The mono-nuclear tetracoordinated silicon compounds N-acetyl-bis-(3,5-di-tert-butyl-2-oxo-phenyl)-amide-bis-(dimethylsilane) (8) and N-acetyl-bis-(3,5-di-tert-butyl-2-oxo-phenyl)-amide-bis-(diphenylsilane) (9) were synthesized from N-(3,5-di-tert-butyl-2-phenol)acetamide (7) and Cl₂SiR₂ (R = Me and Ph). Comparison of the ²⁹Si NMR chemical shifts of the penta- (2 and 3) and tetracoordinated (8 and 9) silicon compounds provided information about the intramolecular coordination of the carbonyl group to the silicon atom. Compounds 3 and 6 were characterized by single-crystal X-ray analyses. They have planar hexacyclic structures where the central atoms present distorted tbp geometries with one nitrogen and two carbon atoms in equatorial positions and two oxygen atoms in apical positions.     

Cobalt(III) Bis-o-semiquinone Complexes with 1-Aryl-3,5-Diphenylformazan Ligands: Synthesis,Structures, and Magnetic Properties

Russian Journal of Coordination Chemistry - New heteroligand cobalt(III) bis-3,6-di-tert-butyl-o-benzosemiquinone complexes with 1-(p-X-phenyl)-3,5-diphenylformazan ligands Co(3,6-SQ)2LX (Х...     

Synthesis and Biological Activities of Novel 1,4-Bridged Bis-1,2,4-Triazoles,Bis-1,3,4-Thiadiazoles and Bis-1,3,4-Oxadiazoles

Abstract

The terephthalic acid hydrazide(1) reacted with phenyl/benzyl isothiocyanate2a,bto yield the corresponding bis-thiosemicarbazides4a,b,viaacid hydrolysis of the intermediate 3whereas cyclization of4gave the bis-1,2,4-triazoles 5,6and bis-1,3,4-thiadiazoles7,8. Similarly, compound 1reacted with phenyl isocyanate9to give the bis-semicarbazide10, which was cyclized to the bis-oxadiazole 11and/or bis-1,2,4-triazole12in POCl_ti3and NaOH respectively.     

(3,5-Diallylisocyanuratomethyl)phosphine oxides and some of their properties

Reaction of sodium diallylisocyanurate with tris(chloromethyl)-, bis(chloromethyl)phenyl-, and (chloromethyl)diphenylphosphine oxides yields, depending on the stoichiometric ratio of the reagents, mono-, bis-, and tris(3,5-diallylisocyanuratomethyl)phosphine oxides.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Science Center, Russian Academy of Sciences, 420083 Kazan, Tatarstan, Russia. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 12, pp. 2773–2777, December, 1992.     

Si-Tethered Bis- and Tris-Malonates for the Regioselective Preparation of Fullerene Multi-Adducts

Bis- and tris-malonates constructed around a silicon atom have been prepared by reaction of malonate derivatives bearing an alcohol function with di-tert-butylsilyl bis(trifluoromethanesulfonate) and tert-butyl(trichloro)silane, respectively. These compounds have been used for the regioselective bis- and tris-functionalization of C₆₀ under Bingel conditions. By changing the nature of the linker between the central Si atom and the reactive malonate groups, the malonate precursors have been optimized to produce specific bis- and tris-adducts with excellent regioselectivity. A complete understanding of the electronic and stereochemical factors governing the regioselectivity has been obtained by combining computational studies with a complete analysis of the by-products formed during the reactions of the Si-tethered tris-malonates with C₆₀. Finally, desilylation reactions of the resulting fullerene bis- and tris-adducts have been carried out to generate the corresponding acyclic fullerene bis- and tris-adducts bearing alcohol functions.     

Hexacoordinate triphenylantimony(V) complex with tridentate bis-(3,5-di-tert-butyl-phenolate-2-yl)-amine ligand: Synthesis,NMR and X-ray study

The oxidative addition reaction of 4,6-di-tert-butyl-N-(2-hydroxy-3,5-di-tert-butyl-phenyl)-o-iminobenzoquinone (IBQ) to triphenylantimony(III) proceeds with the migration of hydroxyl-proton to a nitrogen atom to form tridentate O,N,O′-coordinated bis-(3,5-di-tert-butyl-phenolate-2-yl)-amine ligand. In accordance with ¹H, ¹³C, DEPT NMR data, the new hexacoordinate complex [bis-(3,5-di-tert-butyl-phenolate-2-yl)-amine]triphenylantimony(V), [(AP-AP)H]SbPh₃ (1) in solution has a C_s symmetry plane leading to the equivalence of two O,N-chelate o-aminophenolato moieties. The molecular structure of 1 · acetone was studied by a single-crystal X-ray. Compound 1 was found to be air-stable both in solid and in solution. Its oxidation by PbO₂ leads to paramagnetic [4,6-di-tert-butyl-N-(3,5-di-tert-butyl-phenolate-2-yl)-o-iminobenzosemiquinolato]triphenylantimony(V), [(AP-ISQ)]SbPh₃ (2).     

Diastereoselective synthesis of cis-3- and 3,5-alkylpyrrolizidines

Cis-3 and 3,5-substituted pyrrolizidines can be prepared from β-enaminolactones. Substituted pyrrolidinoketones lead to these compounds by an amino reductive annelation with a low diastereomeric excess, but a best access to these azabicycles consists in preparing cis-2,5-disubstituted pyrrolidines which are then transformed into the expected heterocycles.     

Efficient synthesis of methyl 3,5-di-O-benzyl-alpha-D-ribofuranoside and application to the synthesis of 2'-C-beta-alkoxymethyluridines

Methyl 3,5-di-O-arylmethyl-alpha-D-ribofuranosides have been used extensively as synthons to construct 2'-C-branched ribonucleosides. Herein, we describe efficient access to methyl 3,5-di-O-arylmethyl-alpha-D-ribofuranosides (aryl: 2-ClC(6)H(4), 3-ClC(6)H(4), 4-ClC(6)H(4), 4-BrC(6)H(4), 2,4-Cl(2)C(6)H(3), Ph) in 72-82% yields from methyl D-ribofuranoside. We also demonstrate efficient access to the versatile precursor methyl 3,5-di-O-benzyl-alpha-D-ribofuranoside (3f) and the synthesis of 2'-C-beta-methoxymethyl- and 2'-C-beta-ethoxymethyluridine in six steps from 3f with overall yields of 18% and 32%, respectively.     

Bis-1,2,3-thiaselenazolyl radicals and their sigma-bonded dimers

Resonance stabilized bis-1,2,3-thiaselenazolyl radicals associate in the solid state to afford Se-Se sigma-bonded dimers.     

Preparation and Characterisation of a Bis-μ-Hydroxo-NiIII2 Complex

Hydroxide-bridged high-valent oxidants have been implicated as the active oxidants in methane monooxygenases and other oxidases that employ bimetallic clusters in their active site. To understand the properties of such species, bis-μ-hydroxo-Ni^II₂ complex ( 1 ) supported by a new dicarboxamidate ligand (N,N′-bis(2,6-dimethyl-phenyl)-2,2-dimethylmalonamide) was prepared. Complex 1 contained a diamond core made up of two Ni^II ions and two bridging hydroxide ligands. Titration of the 1 e⁻ oxidant (NH₄)₂[Ce^IV(NO₃)₆] with 1 at −45 °C showed the formation of the high-valent species 2 and 3 , containing Ni^IINi^III and Ni^III₂ diamond cores, respectively, maintaining the bis-μ-hydroxide core. Both complexes were characterised using electron paramagnetic resonance, X-ray absorption, and electronic absorption spectroscopies. Density functional theory computations supported the spectroscopic assignments. Oxidation reactivity studies showed that bis-μ-hydroxide-Ni^III₂ 3 was capable of oxidizing substrates at −45 °C at rates greater than that of the most reactive bis-μ-oxo-Ni^III complexes reported to date.     

Bis-(trialkylsilyl) phosphonates

Summary Methods of synthesis of the previously unknown bis-(trialkylsilyil) phosphonates were developed on the basis of reaction of phosphorous acid with trialkylchlorosilanes or trialkylalkoxysilanes. Their Raman spectra were studied.     

Synthesis of 3,5-disubstituted 1,2,4-triazoles containing trimethoxyphenyl groups: Potential antagonists of platelet activating factor

In an effort to develop a new class of Platelet Activating Factor antagonists, 3,5-disubstituted 1,2,4-triazoles containing trimethoxyphenyl groups have been synthesized. The synthesis of symmetrical triazoles 5 and 6 , as well as two methods of synthesizing unsymmetrical triazole 7 , are reported.     

Synthetic, Mechanistic, and Structural Studies Related to 1,2,4-Dithiazolidine-3,5-dione

Reaction of O-ethyl thiocarbamate (4) with (chlorocarbonyl)sulfenyl chloride (5) gives 3-ethoxy-1,2,4-dithiazolin-5-one (2) and 3,5-diethoxy-1,2,4-thiadiazole (3), with the relative amounts of 2 and 3 formed depending very much on the solvent (e.g., diethyl ether favors 2; chloroform favors 3). The effects of added base, order of addition, concentration, and temperature were also studied. Mechanisms for the observed transformations have been proposed and are supported by the characterization of relatively unstable acyclic intermediates, e.g., formimidoyl(chlorocarbonyl)disulfane 8, symmetrical bis(formimidoyl)disulfane 10, and ethoxythiocarbonyl imidate 11, which are obtained under alternative conditions. Compound 2 is converted with concentrated aqueous hydrochloric acid upon short reflux to 1,2,4-dithiazolidine-3,5-dione (1), rearranges upon prolonged melting to give principally N-ethyl-1,2,4-dithiazolidine-3,5-dione (13), and is desulfurized with various trivalent phosphorus compounds to yield O-ethyl cyanate (15) plus carbonyl sulfide. X-ray crystallographic structures of 1 and 2 have been solved; the planarity and aromatic character of these molecules help to explain some of their reactions.     

Bis-β,β′-conjugate addition

Addition of organocuprates to α,β-enones which possess on the β′-carbon a heteroatom substituent leads in good to excellent yield to β,β′-dialkylated ketones. This process is termed bis-β,β′-conjugate addition.     

3,5-二烷氧基甲苯的溴化反应研究

3,5-二甲氧基甲苯在偶氮二异丁腈的存在下与N-溴代丁二酰亚胺(NBS)反应,产物不是3,5-二甲氧基苄溴,而是2-溴-3,5-二甲氧基甲苯和2,6-二溴-3,5-二甲氧基甲苯.同样条件下,3,5-二乙酰氧基甲苯与NBS反应则生成3,5-二乙酰氧基苄溴.GAUSSIAN 03计算的结果表明,3,5-二甲氧基甲苯中苯环碳原子上的电荷密度高于侧链上碳原子上的电荷密度,因此溴自由基更容易取代苯环上的氢,而3,5-二乙酰氧基甲苯的情况恰好相反,故产物是3,5-二乙酰氧基苄溴.     

Synthesis and Fungicidal Activity of Bis-1,5,3-dithiazepanes and Crown-Like Macroheterocycles

Russian Journal of General Chemistry - An efficient method was developed for the synthesis of bis-1,5,3-dithiazepanes and crown-like N-cycloalkyl-1,11-dioxa-4,8-dithia-6-azacyclotridecanes by...     

Synthesis and Crystal Structure of the Intermediate Bis-9-fluorenylmethylphenyl Silane

1 INTRODUCTION The title compound bis-9-fluorenylmethyl- phenyl silane is an intermediate to synthesize the rare earth organometallic complexes containing silylene-bridged ligand. It was synthesized from fluorenyl lithium reacting with dichlorine (methyl) phenylsilane. In this experiment, however, a new method was taken. In the first step fluorenyl lithium was prepared from fluorene reacting with metal lithium directly instead of with n-butyllithium, which not only reduces the by-produc…