Copper-mediated synthesis of mono- and dichlorinated diaryl ethers

An efficient synthesis of polychlorinated diphenyl ethers (PCDEs) using the Cu(OAc)₂-catalyzed Chan–Lam coupling reaction is described. A library of all possible mono- and dichlorinated diphenyl ether congeners was prepared and characterized using MS, ¹H, and ¹³C NMR spectroscopy, and Kovats retention indices. Our approach, using the optimized reaction conditions (i.e., reaction temperature, oxidizing atmosphere and base), significantly improves and simplifies the process compared to previously reported syntheses.     

Copper-mediated synthesis of phthalocyanino-fused Dehydro

Cyclooligomeric phthalocyanines with the special feature of having a dehydroannulene core are described. Compounds 4a,b and 5a,b were prepared by an oxidative coupling mediated by copper from the corresponding diethynyl unsymmetrically substituted phthalocyanines 8a,b, which are easily accessible from the corresponding diiodo compounds 6a,b by a palladium-copper-catalyzed coupling. Appropriate conditions to selectively form cyclodimers and cyclotrimers using Glaser and Eglinton methodologies have been attempted. In this way, two compounds, 4a and 5b, each representative of a kind of oligomers, could be appropriately isolated and characterized by MALDI-MS. The UV-vis spectra of compounds 4a and 5b show a split Q-band shifted to the red with respect to the corresponding precursor 8a,b. This can be interpreted, in light of previous results, as a consequence of intramolecular electronic coupling between the Pc subunits. Extensive formation of aggregates in chloroform can be also inferred from the spectra. No significant differences could be observed in the spectra by comparison with that of the open-chain analogue 11, most probably due to a saturation phenomenon of the optical properties already pointed out in the literature for other alkynyl-linked open-chain dimers.     

Pd-NHC-catalyzed synthesis of diaryl ketones

With N-hetereocyclic carbene and palladium catalysis, diaryl ketones with a variety of functional groups that span from electron withdrawing to electron donating substitutions can be conveniently synthesized using the corresponding aryl boronic acid and N-acyloxyphthalimide.     

Copper-mediated synthesis of PdI_2 colloidal spheres

A novel copper-mediated solvothermal method was proposed for synthesizing colloidal spheres of a new composition,palladium iodide(PdI2).Typical procedure was designed to involve the introduction of cupric chloride(CuCl2) as weak oxidant.CuCl2 was found to be essential for preventing the easy formation of palladium deposits as well as facilitating the synthesis and assembly.Under the co-effect of CuCl2 and the surfactant of polyvinylpyrrolidone(PVP),neutral PdI2 colloidal spheres with narrow size distributio...     

Ultrasound synthesis of diaryl ethers

Russian Chemical Bulletin - 2,2-Bis[4-(4-nitroaryl)phenyl]hexafluoropropanes appropriate for the synthesis of monomers were prepared by the reaction of 2,2-bis[4-hydroxyphenyl)hexafluoropropane...     

Modular ligands in asymmetric synthesis. Copper-mediated cyclopropanation

The chiral imidazoline/copper catalyst system efficiently mediates asymmetric intermolecular cyclopropanations. Complexes derived from (R,R)- or (S,S)-1,1-diphenylethylenediamine, cyclic ketones, and Cu(I) or Cu(II) triflates were compared. The reaction between (−)-menthyl diazoacetate and 1,1-diphenylethylene affords cyclopropane carboxylates in up to 80% yield and with up to 78% de.     

Microwave-assisted synthesis of diaryl ethers without catalyst

[reaction: see text] Diaryl ethers have been prepared by direct coupling of phenols including those that bear a strong electron-attracting substituent to electron-deficient aryl halides through S(N)Ar-based addition reactions with assistance of microwave irradiation in high to excellent yields within 5-10 min. No catalysts were required under our conditions.     

Visible-light-promoted synthesis of diaryl sulfides under air

A convergent, organocatalytic visible-light-mediated process for the synthesis of diaryl sulfides has been developed. A broad range of aryl thiols reacted with various aryl diazonium salts in the presence of eosin Y under air atmosphere to afford the desired diaryl sulfides in high yields. This novel and environmentally friendly method provides an alternative route to established synthetic approaches.     

Copper-mediated synthesis of N,N''''-diarylhydrazines from boronic acids

N,N0-Diarylhydrazines have been prepared via the reaction of N-Boc-aryl hydrazines with boronic acids mediated by copper acetate. This mild reaction condition tolerates the presence of a variety of functional groups.     

Regiospecificity in the synthesis of diaryl sulfones

The addition of arylsulfinic acids to 2-methyl-1,4-benzoquinone provides high yields of sulfones in a wide variety of solvents. The distribution of isomeric products obtained is strongly influenced by either (1) the acidity of aqueous solvents or (2) the water content of alcohol solvents. The distribution of isomeric products does not change in the various anhydrous, aprotic solvents examined.     

Copper-mediated cleavage of disulfides by tertiary phosphines: a new route to As-S anions

The synthesis of [(PhAs)2(micro-S2)(micro-S)] and its reactions to form novel Cu(I) complexes are reported, together with a new cleavage reaction of disulfides by Cu(I) thiolates and tertiary phosphines.     

Solution-phase synthesis of diaryl selenides using polymer-supported borohydride

[reaction: see text] A new series of selenium-containing diaryl retinoids have been prepared by a new direct nickel(II)-catalyzed coupling of a diselenide with an iodoaryl in the presence of polymer-supported borohydride.     

An efficient Cu-catalyzed microwave-assisted synthesis of diaryl sulfones

An efficient and microwave-assisted simple protocol for the synthesis of symmetrical/asymmetrical diaryl sulfones through the Cu(II)-catalyzed reaction of sodium salt of sulfinic acid with aryl boronic acid has been described. Various diaryl sulfones have been synthesized in very short reaction times with moderate to very good yields. Additionally, the method is also useful for the synthesis of aryl vinyl sulfones.     

相转移催化法合成已二酰基二芳基双硫脲化合物

酰基硫脲类化合物具有广泛的生物活性,可用作杀虫剂、杀菌剂、抗病毒剂和植物生长调节剂等,但关于双酰基硫脲化合物的研究较少。根据活性子叠加原理,为了寻找高生物活性的新化合物,我们从已二酸出发,经酰化得到已二酰氯,然后以PEG-400为相转移催化剂,与硫氰酸铵作用后不经分离直接与芳胺反应,一锅法合成了9种新的已二酰基二芳基双硫脲化合物。其结构经元素分析、IR及^1HNMR确证。合成路线如下。     

Microwave-assisted synthesis of diaryl or aryl-alkyl sulfones without catalyst

The microwave-assisted coupling reaction of electrondeficient aryl halides with sulfmic acid salts through SNAr-based addition reactions within 5-30 min. No catalysts were required under our conditions.     

A general and mild Ullmann-type synthesis of diaryl ethers

[reaction: see text] An efficient method for the synthesis of diaryl ethers under particularly mild conditions is described. Inexpensive ligands were found to greatly accelerate the Ullmann-type coupling of aryl bromides or iodides with phenols. A series of diaryl ethers were obtained with excellent yields in acetonitrile in the presence of Cs(2)CO(3) and catalytic copper(I) oxide. The reaction tolerates substrates with unfavorable substitution patterns, such as sterically hindered coupling partners or electron-rich aryl halides.     

Copper-mediated synthesis of N-vinyl ynamides from N-vinyl carbamates

Ynamides are versatile 3-atoms building blocks for organic synthesis as they participate in a variety of ionic, radical and pericyclic processes. Converting ynamides into 5-atom building blocks, such as the yet unreported N-vinyl ynamides, would open new avenues in this fascinating chemistry. We describe herein our efforts towards such goal and demonstrate that the cross-coupling between N-vinyl carbamates and bromo-alkynes using copper(I) thiophene carboxylate, 1,10-phenanthroline and tBuOK in DMSO is a reactive system with an improved profile compared to the classical ynamides syntheses. The advantages and limitations of this copper-mediated reaction are discussed.     

A catalyst-free synthesis of asymmetric diaryl ketones from aryltins

A series of diaryl ketones have been synthesized in good yields (40-78%) through the catalyst-free reaction of trimethylarylstannanes with aroyl chlorides in chlorobenzene as solvent. In addition, an attractive feature is that these reactions are completely regioselective making possible the synthesis of diarylketones which are not usually available under the influence of the directing forces of the substituents present in the aromatic ring. Also, the reaction conditions are mild enough to be applied to acid sensitive molecules.