Extraction of neptunium(VI) from nitric acid solution with di(1-methyl-heptyl) methyl phosphonate

Journal of Radioanalytical and Nuclear Chemistry - The extraction behaviors of Np(VI) from nitric acid medium by di(1-methyl-heptyl) methyl phosphonate (DMHMP) diluted in kerosene has been...     

Preparation of di(n-butyl) tin and di(n-octyl) tin dihalides by the direct synthesis method

The direct synthesis of the two industrially important organotin intermediates, di(n-butyl)tin and di(n-octyl)tin dihalides, has been investigated by reacting the appropriate alkyl halide with metallic tin undervarying conditions. Observations were made on the influences of temperature, pressure, reaction time, nature of the tin metal, organic halide/tin reactant ratios and the presence of catalysts on the extent of tin conversion and yields of the organotin products. The efficacy of the onium halides, notably n-Bu₄NI, Me₃SI and Ph₃MeAsI, either singly or in binary combinations with iodine or inorganic iodine compounds, in catalysing the synthesis of the above dialkyltins as well as higher di(n-alkyl)tin analogues is described.     

First Synthesis of Bis(di(indolyl)aryl)methanes From Bis(salicylaldehydes)

In this article, a simple method for the synthesis of bis(di(indolyl)aryl)methanes is described. The iodine‐catalyzed (5 mol %) reaction of indoles with various bis(salicylaldehyde) derivatives affords the bis(di(indolyl)aryl)methanes in excellent yields. The reaction works well under mild reaction condition with shorter reaction time.     

Synthesis of aryl(di)azinyl ketones through copper- and iron-catalyzed oxidation of the methylene group of aryl(di)azinylmethanes

Sustainable Oxidations: an oxidation method to transform aryl(di)azinylmethanes into aryl(di)azinyl ketones is described. Base metals (copper and iron) as catalysts in combination with O(2) as the oxidant are used, which makes this method sustainable. The utility of this method is illustrated by the synthesis of 6-(4-methylbenzoyl)pyridine-2-carbaldehyde, which is an intermediate in the preparation of the drug Acrivastine.     

Selective synthesis of di(propen-1-yl)sulfone and di(propen-1-yl)sulfoxide

Convenient selective methods of synthesis of the title compounds, based on oxidation of di(propen-1-yl)sulfide with 30% H₂O₂, have been developed.Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 675–679, March, 1992.     

Gold(I)-catalyzed sequential cycloisomerization/bis-addition of o-ethynylanilines: an efficient access to bis(indolyl)methanes and di(indolyl)indolin-2-ones

An efficient synthesis of bis(indolyl)methanes and di(indolyl)indolin-2-ones has been developed by a sequential approach involving gold(I)-catalyzed cycloisomerization/bis-addition of o-ethynylanilines with various aldehydes and isatins, respectively. This methodology opens clean and synthetically competitive alternative to the already established procedures of the synthesis of bis(indolyl)methanes and di(indolyl)indolin-2-ones.     

A novel synthesis of (di)-benzazocinones via an endocyclic N-acyliminium ion cyclisation

The triflic acid-mediated endocyclic N-acyliminium ion cyclisation provides a facile synthesis of (di)-benzazocinones. On reduction of the 10-phenyl derivative, an unusually non-polar tertiary alkylamine was obtained.     

Synthesis of di(hetero)aryl sulfides by directly using arylsulfonyl chlorides as a sulfur source

A new, efficient protocol for the synthesis of di(hetero)aryl sulfides is described. Cheap and easily available arylsulfonyl chlorides as a sulfur source reductively couple with electron-rich (hetero)arenes (e.g., indolizines, indoles, electron-rich benzenes, etc.) in the presence of triphenylphosphine to afford di(hetero)aryl thioethers in good yields.     

Stereospecific Pd(O)-catalyzed malonate additions to allylic hydroxy phosphonate derivatives: a formal synthesis of (-)-enterolactone

A combination of cross-metathesis and malonate addition was applied to a formal synthesis of the mammalian lignan enterolactone 5. The cross-metathesis of alkene 6 and phosphonate 3a gave the substituted allylic phosphonate 3d. The palladium-catalyzed addition of malonate 10d to the allylic phosphonate 3d was stereospecific and highly regioselective and yielded the vinyl phosphonate 11d. The vinyl phosphonate 11d was converted in two steps into the lactone 14, a known intermediate in the synthesis of enterolactone 5.     

Synthesis of di(Imdazolium) and di(Pyrazolium) Salts as Precursors for N-heterocyclic Dicarbene Complexes

Alpha,omega-bis(pyrazol-1-yl)alkanes and alpha,omega-bis(imidazol-1-yl)alkanes with spacers consisting of four to ten methylene groups have been prepared from pyrazole, 3,5-dimethylpyrazole or imidazole and corresponding dibromoalkanes in a superbasic medium KOH-DMSO. The proposed method of synthesis allowed the preparation of new flexible bidentate ligands without the need to use toxic solvents and tedious workup procedures. Bis(pyrazol-1-yl)alkanes were further functionalized for their use as precursors for “non-classical” mesoionic N-heterocyclic carbene ligands. One the first step, iodine atoms were introduced to positions 4 of pyrazole rings by oxidative iodination using I₂-HIO₃ system. On the next step, nitrogen atoms in positions 2 of pyrazole rings were alkylated using several agents. Reaction with methyliodide unexpectedly led to the formation of only mono-alkylated products even after 7 days of refluxing in a neat alkyliodide. Methylation by trimethyloxonium tetrafluoroborate or methyltriflate led to dimethylated products in high yields. Bis(imidazol-1-yl)alkanes were easily alkylated by methyliodide to give di(imidazolium) salts – precursors to “classic” N-heterocyclic dicarbenes.     

Synthesis and analytical properties of di(2-pyridyl)-N,N-di[(8-quinolyl)amino]methane

The synthesis and preliminary analytical assessment of di(2-pyridyl)-N,N-di[(8-quinolyl)-amino]methane is reported. It shows some potential as a reagent for iron(II).     

Syntheses of 3-substituted furans via lithium di(3-furyl)cuprate—the application of lithium di(3-furyl)cuprate to the total synthesis of dendrolasin

One step syntheses of 3-substituted furans by the reactions of a new reagent, lithium di(3-furyl)cuprate $\text{1}$, with various substrates and the application of $\text{1}$ to a total synthesis of dendrolasin are described.     

Methanolysis of Dimethyl (1-Diazo-2-oxopropyl) Phosphonate: Generation of Dimethyl (Diazomethyl) Phosphonate and Reaction with Carbonyl Compounds

Dimethyl (1-diazo-2-oxopropyl) phosphonate (3) was transformed to dimethyl (diazomethyl)—phosphonate (4), which was used for the synthesis of enol ether or alkyne without isolation.     

Convenient route to dialkyl diselenides from alkyl tosylates. Synthesis of di(cis-myrtanyl) diselenide

A one-step method for the synthesis of dialkyl diselenides, by reaction of alkyl tosylates with sodium diselenide is described. Three variants of the synthesis, using as an example the preparation of optically active di(cis-myrtanyl) diselenide, are compared.     

Characteristics of industrial di(alkylphenyl)dithiophosphoric acids

Instrumental and classical methods have been used to characterize some industrial di(alkylphenyl)dithiophosphoric acids. The (31)P-NMR chemical shifts of di(nonylphenyl)dithiophosphoric acid and its derivatives are summarized.     

Synthesis of symmetrical di(pyrimidin-2-yl)-1,2,4-triazoles and di(pyrimidin-2-yl)-1,2,4,5-tetrazines

The reactions of pyrimidine-2-carbonitrile and 4,6-dimethylpyrimidine-2-carbonitrile with hydrazine hydrate were investigated. Intermediates in the route of successive transformations of pyrimidine-2-carbonitrile (pyrimidine-2-carbamidrazone and 1,2-bis[amino(pyrimidin-2-yl)methylidene]hydrazine) into trinuclear heterocyclic compounds, viz., symmetrical di(pyrimidin-2-yl)-1,4-dihydro-1,2,4,5-tetrazines and di(pyrimidin-2-yl)-4H-1,2,4-triazol-4-amines (potential polydentate ligands), were isolated. The oxidative dehydrogenation of di(pyrimidin-2-yl)-1,4-dihydro-1,2,4,5-tetrazines afforded the corresponding 3,6-di(pyrimidin-2-yl)-1,2,4,5-tetrazines.     

Total synthesis of (-)-anamarine

Total synthesis of polyhydroxy δ-pyranone natural product (-)-anamarine is accomplished from D-(-)-tartaric acid. The main feature of the synthesis is the utility of hitherto unexplored β-keto phosphonate derived from tartaric acid amide and further elaboration involving stereoselective reduction.     

Synthesis and reactivity of di(silylamido)cyclopentadienyl titanium and zirconium complexes

We present in this account the synthesis and recent developments of a new class of group 4 metal complexes with the tridentate di(silylamido)cyclopentadienyl ligand. These doubly silyl-bridged group 4 metal amido chelates are receiving increasing interest as they are efficient catalysts for ethene polymerization when activated with MAO despite generating 14-electron d⁰ cationic species free of the alkyl group required for the first insertion reaction in the polymerization process.     

Bioactive mesoglobules of poly(di(ethylene glycol) monomethyl ether methacrylate)–peptide conjugate

This study describes the synthesis and aggregation behavior of thermosensitive poly(di(ethylene glycol) monomethyl ether methacrylate) (P(DEGMA‐ME)) conjugated with the fluorescently labeled pentapeptide glycine‐arginine‐lysine‐phenylalanine‐glycine‐dansyl (GRKFG‐Dns). The GRKFG‐Dns was obtained using Fmoc solid‐phase peptide synthesis and was modified with 2‐bromopropionic acid to initiate an atom transfer radical polymerization of di(ethylene glycol) monomethyl ether methacrylate (DEGMA‐ME). The polymerization led to a well‐defined P(DEGMA‐ME)–GRKFG‐Dns conjugate with a number average molar mass of 108,000 g/mol. The pentapeptide acted as a hydrophilic moiety that increased the phase transition temperature compared to the P(DEGMA‐ME) homopolymer of similar molar mass. The bioconjugate macromolecules aggregated in dilute aqueous solution into spherical particles (mesoglobules). The sizes of aggregates were easily controlled by changing the concentration and heating rate of the P(DEGMA‐ME)‐GRKFG‐Dns solution. The weight average molar masses and sizes of mesoglobules were determined based on light scattering measurements. Enzymatic hydrolysis of the bioconjugate in dilute solution was performed at temperatures below and above the cloud point temperature of the bioconjugate. The peptides were fully accessible to enzymatic digestion even when the macromolecules were aggregated to mesoglobules, indicating that the peptide segments in mesoglobules formed the external shell of the nanoparticles and could be easily released by enzymes. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Hydrothiolysis of di(2-thienyl) disulfide

Conclusions The hydrothiolysis of di(2-thienyl) disulfide by hydrogen sulfide at 130–180°C leads to the formation mainly of di(2-thienyl) sulfide. 2-Thiophenethiol is formed as a side-product due to the dissociation of the disulfide at the S-S bond and subsequent reaction of the thiol radicals with hydrogen sulfide. Di(2-thienyl) sulfide also undergoes secondary conversions to 2-thienyl 3-thienyl sulfide and 3-thiophenethiol by the addition of thiol radicals at C-3 of the thiophene ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2783–2785, December, 1985.