Synthesis of 2,5-bis[(3,4-ethylenedioxy)thien-2-yl]- 3-substituted thiophenes

[reaction: see text] Synthesis of 2,5-bis[(3,4-ethylenedioxy)thien-2-yl]-3-substituted thiophene monomers afforded compounds with blue emission characteristics and having a quantum yield of 3-5%. Cyclic voltammetry was employed to investigate the electrochemical behavior of the four monomers reported here. Polymer films were deposited by repeated potential cycling. These materials are considered for use in tailoring properties in optoelectronic device applications.     

Synthesis of 1,3-Bis[(3-aryl)-S-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]benzenes

1,3-bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]benzenes 2 were synthesized in high yields by the reaction of 3-aryl 4-amino-5-mercapto-1,2,4-triazole 1 with m-phthalic acid.     

Synthesis and antitumor activity of 3-[(methyl)bis(5-trialkylsilyl-furan-2-yl)silyl]propylamines

Novel 3-[(methyl)bis(5-trialkylsilylfuran-2-yl)silyl]propylamines have been synthesized by a hydrosilylation reaction of aliphatic and heterocyclic N-allylamines in the presence of the Speier's catalyst. The effects of the structure of the amine and the alkyl substituent at the silicon atom on the cytotoxicity of the compounds have been studied.     

Tuning the band gap of easily oxidized bis(2-thienyl)– and bis(2-(3,4-ethylenedioxythiophene))–phenylene polymers

The synthesis, characterization and electrochemical polymerization, along with redox switching behavior of the resultant polymers, of 1,4-bis(2-(3,4-ethylenedioxy)thienyl)–2,5-difluorobenzene ( 1 ) and 1,4-bis(2-thienyl)–2,5-difluorobenzene ( 2 ) is presented. Compounds 1 and 2 were synthesized by a Pd°-catalyzed cross-coupling and in good yields (85% and 84%, respectively). Both monomers electropolymerize to form electroactive redox switchable films, with the more electron-rich 3,4-ethylenedioxythiophene derivative polymerizing and switching at lower potentials. The electronic band gaps were determined to be 1.9 eV for P1 and 2.3 eV for P2. Thin films of P1 and P2 were found to be electrochromic and exhibit color changes of red-to-blue/black for P1 and yellow-to-black for P2. These results are compared with various substituted bis(heterocycle)benzene derivatives in order to present a series of structure to property relationships. © 1998 John Wiley & Sons, Ltd.     

Synthesis and properties of novel organosoluble polyimides derived from bis[3-(4-amino-2-trifluoromethylphenoxy) phenyl] ether

A new aromatic ether diamine, bis[3-(4-amino-2-trifluoromethylphenoxy) phenyl] ether, was successfully synthesized via nucleophilic substitution reaction of 3,3′-oxydiphenol and 2-chloro-5-nitrotrifluoromethylbenzene, followed by a catalytic reduction. A series of new polyimides were synthesized from the diamine with various commercially available aromatic dianhydrides via a conventional two-stage process, i.e. ring-opening polyaddition forming the poly(amic acid)s and further thermal or chemical imidization forming polyimides. The resulting polyimides exhibited good solubility in polar solvents, such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidinone and common solvents such as chloroform, tetrahydrofuran upon heating and possessed the inherent viscosities of 0.51-0.68 dL/g. The resulting strong and flexible films exhibited excellent thermal stability with the temperature at 10% weight loss is above 502 °C and the glass transition temperature in the range of 191-232 °C. The polyimides also were found to possess high optical transparency.     

Synthesis of volatile bis[bis(trimethylsilyl)amide]-substituted boron derivatives

Russian Journal of General Chemistry - General strategy for the synthesis of organoboron compounds containing bis(trimethylsilyl)amide substituents has been suggested.     

Synthesis of 2-diphenylphosphinoyl-3,5-diaryl-3,4-dihydro-2H-telluropyrans by reaction of chalcones with bis[(diphenylphosphinoyl)methyl]telluride

The NaH-promoted tandem Michael addition/intramolecular Wittig-Horner reaction of bis[(diphenylphosphinoyl) methyl]telluride with chalcones stereoselectively afforded trans-2-diphenylphosphinoyl-3,5-diaryl-3,4-dihydro-2H-telluropyran derivatives in 51-72% yield, under mild conditions.     

Synthesis of 4-[(3,3-Dimethyl-3,4-dihydroisoquinolin-1-yl)sulfanyl]anilines by the Ritter Reaction

Russian Journal of Organic Chemistry - The Ritter cyclocondensation of 2-methyl-3-phenylpropan-2-ol with 4-isocyanatoaniline, 2-methyl-4-thiocyanatoaniline, and ethyl 4-amino-3-thiocyanatobenzoate...     

Synthesis,crystal structure and physicochemical properties of copper(II) complexes containing bis[(benzimidazol-2-yl)methyl] ether derivatives

A new benzimidazoyl ligand bis[(N-ethylbenzimidazol-2-yl)methyl]ether (EDGB) and Cu^II complexes [Cu(L¹) (L²)](ClO₄)·mEt₂O·nH₂O [L¹ = bis[(benzimidazol-2-yl)methyl]ether (DGB) or EDGB, L² = 2,2-bipyridine (bipy) or 1,10-phenanthroline (phen)] have been synthesized and characterized by elemental analyses and i.r. spectra. The single-crystal structure of the [Cu(phen)(DGB)(OClO₃)]ClO₄·Et₂O·0.5H₂O complex was determined by X-ray diffraction. The geometry around Cu is best described as a distorted octahedron with four nitrogen atoms from phen and DGB ligands forming the equatorial plane. The oxygen atoms of DGB and one perchlorate group are in the axial positions with semi-coordinated bonding modes. The electrochemical behavior of the complexes is described.     

Synthesis of 2-substituted 3,4-bis(diethoxyphosphorylmethyl)furans

Bromination of ethyl 4-(diethoxyphosphorylmethyl)-5-methylfuran-2-carboxylate and 4-(diethoxyphosphorylmethyl)-5-methylfuran-2-carbonitrile with N-bromosuccinimide followed by phosphorylation via the Arbuzov reaction have yielded the corresponding 2-substituted 4,5-bis(diethoxyphosphorylmethyl)furans. Synthesis and transformations of bisphosphorylated 2-furoic acid and its derivatives are described.

     

Synthesis of 4-(thien-2-yl)-substituted coumarins through Lewis acid catalyzed Michael addition of thiophenes to 3-benzoylcoumarins followed by oxidation

3-Benzoyl-4-(thien-2-yl)coumarins have been obtained in good yields according to the S_N^H addition–oxidation protocol, involving the diastereoselective addition of thiophenes at C-4 of 3-benzoylcoumarins under BBr₃ catalysis, followed by oxidation of the intermediate 3,4-trans-3-benzoyl-4-(thien-2-yl)-3,4-dihydrocoumarins with DDQ. This two-step procedure can be regarded as nucleophilic substitution of hydrogen (S_N^H) on the heterocyclic ring of coumarins.     

Simple one-step synthesis of 3,4-dimethoxythiophene and its conversion into 3,4-ethylenedioxythiophene (EDOT)

3,4-Dimethoxythiophene (2) was synthesized in one-step from readily available bulk chemicals via a ring closure reaction, and was then trans-etherified with ethylene glycol to give 3,4-ethylenedioxythiophene (3) (EDOT).     

Synthesis of mono- and bis-arylated 3,4-(ethylenedioxythiophenes) via direct palladium catalyzed arylation reactions

The synthesis of arylated/heteroarylated 3,4-ethylenedioxythiophene derivatives is reported using a straightforward palladium mediated Heck coupling of 3,4-ethylenedioxythiophene with various aryl/heteroaryl halides.     

2-芳基-5-[(4-芳基噻唑-2-基)甲基]-1,3,4-噁二唑的合成

以硫代酰胺和α-溴代酮为原料,经4步反应合成了N,N′-二酰基肼(6),6在POCl3作用下脱水环化,合成了7个未见文献报道的2-芳基-5-[(4-芳基噻唑-2-基)甲基]-1,3,4-噁二唑类化合物,其结构经1H NMR,IR,MS和元素分析表征。     

Acid-induced dimerisation of 1,2-di(thien-2-yl)ethanone

Treatment of 1,2-di(thien-2-yl)ethanone with aqueous 75% (v/v) sulfuric acid gives a dimer in which the units are linked head-to-head via a thiophene-tetrahydrothiophene bond.     

Synthesis of (purin-6-yl)methylphosphonate bases and nucleosides

Three approaches to the synthesis of the title (purin-6-yl)methylphosphonates were investigated and compared. While, the Arbuzov reaction of 6-(iodomethyl)purines with triethyl phosphite did not work, Michaelis-Becker alkylation of the sodium salt of diethyl phosphonate with 6-(mesyloxymethyl)purines gave the desired products in good yields. The best method was based on Rh- or Pd-catalyzed cross-coupling reactions of 6-iodopurines with (diisopropoxyphosphorylmethyl)zinc bromide. In this way a small series of 6-(diisopropoxyphosphorylmethyl)purine bases and nucleosides was prepared in high yields.