Facile synthetic procedure for and electrochemical properties of hexa(2-thienyl)benzenes directed toward electroactive materials

In the presence of RhCl₃·3H₂O and i-Pr₂NEt, the cyclotrimerization of di(2-thienyl)acetylenes proceeded smoothly to afford hexa(2-thienyl)benzenes. CV analysis of the hexa(2-thienyl)benzenes showed that they may be useful as electroactive materials.     

X-Ray structure analyses of diphosphinidenecyclobutene and its chelate type tetracarbonylmolybdenum(O) complex

The structure of [(E,E)-3,4-bis(2,4,6-tri-t-butylphenylphosphinidene)-1,2-bis(trimethylsilyl)cyclobutene]tetracarbonylmolybdenum(O) has been analyzed by X-ray crystallography. The structure of the free ligand, diphosphinidenecyclobutene, has also been analyzed and compared with that of the metal carbonyl complex.     

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.     

Synthesis and properties of 2-(2-furyl)-and 2-(2-Thienyl)-1,3-benzoxazoles

Condensation of o-aminophenol with furoyl and thenoyl chlorides in 1-methylpyrrolidin-2-one gave, respectively, 2-(2-furyl)- and 2-(2-thienyl)-1,3-benzoxazoles in which the furan and thiophene rings showed no acidophobic properties. Reactions of 2-(2-furyl)- and 2-(2-thienyl)-1,3-benzoxazoles with electrophilic reagents (acylation, bromination, nitration, and sulfonation) afforded products of hydrogen replacement in both hetaryl and benzene rings, depending on the conditions.     

Chloromethylation of substituted di(2-thienyl)methanes and the reductive desulfuration of some diamines of the thiopene series

The action of chloromethyl ether on di(2-thienyl)methane, 1, 1-di-(2-thienyl)ethane, 2, 2-di(2-thienyl)propane, 2, 5-bis(dimethyl-2-thienylmethyl)thiophene, and 1, 1, 1-tri(2-thienyl)ethane has given, respectively: 5-chloromethyl -2 -thienylthiophene, 1, 1-bis(5-chloro-methyl-2-thienyl)ethane, 2, 2-bis(5-chloromethyl-2-thienyl)propane, 2, 5-bis(dimethyl-5-chloromethyl-2-thienylmethyl)thiophene, 1-(2-thienyl)-1, 1-bis(5-chloromethyl-2-thienyl)-ethane, and the corresponding amines: 5-diethylaminomethyl-2-thienylthiophene, 1,1-Bis(5-diethylaminomethyl-2-thienyl)ethane, 2, 2-bis(5-aminomethyl-2 -thienyl)propane, 2, 2-bis(5-methylaminomethyl-2-thienyl)propane, 2, 5-bis(dimethyl-5-dimethylaminomethyl-2-thienylmethyl)thiophene, and 2, 8, 8, 14, 20, 20-hexamethyl-2, 14-diaza-3, 2, 3, 2-α-cyclotetrathiene. The reductive desulfonation over Raney nickel of the diacetyl derivatives of 2, 2-bis(5-aminomethyl-2-thienyl)propane and 2, 2-bis(5-methylaminomethyl-2-thienyl)propane has given the diacetyl derivatives of aliphatic amines.     

Préparation de dithiényl-2-éthène-1,2, de dithiényl-2-pyrimidine-2,4 et de dithiényl-2-pyridazine-3,6

The condensation of 2-thienylmagnesium bromide with (Z)-1,2-dichloroethene 2,4-dichloropyrimidne, 3,6-dichloropyridazine and with a transition metal catalyst is described. The yields of these reactions are very good; 1,2-bis(2-thienyl)ethene and two new heterocyclic compounds 2,4-bis92-thientyl)pyrimidine and 3,6-bis(2-thienyl)pyridazine were obtained in one step from commercial products.     

Interaction of (z)-4-bromo-1,3-di(2-thienyl)- 2-buten-1-one with amines,synthesis of di(2-thienyl)azolo[<Emphasis Type="Italic">a</Emphasis>]pyridines

(Z)-4-Bromo-1,3-di(2-thienyl)-2-buten-1-one was obtained by the bromination of 1,3-di(2-thienyl)-2-buten-1-one by NBS in anhydrous CCl₄. The starting butanone was obtained by the condensation of 1-(2-thienyl)-1-ethanone by the action of SOCl₂. The reaction of (Z)-4-bromo-1,3-di(2-thienyl)-2-buten-1-one with tertiary amines such as Et₃N, pyridine, 1-alkyl-1,3-diazole, 1-alkylbenzimidazole, and 1-alkyl-1,2,4-triazole leads to quaternary salts. The azolium salts cyclize by the action of base to give di(2-thienyl)azolo[a]pyridinium derivatives. 3-Methyl-6,8-di(2-thienyl)[1,3]thiazolo[3,2-a]pyridin-4-ium and 2,4-di(2-thienyl)pyrido[2,1-b]benzothiazol-10-ium bromides were obtained by the same procedure but without separating the intermediate quaternary salts.     

Synthesis and characterization of β-diketiminate germanium(II) compounds

Reactions of LGeCl (L = CH[C(Me)N(Ar)](2); Ar = 2,6-iPr(2)C(6)H(3)) with KOtBu or LiR (R = 2-thienyl, N(H)Ar, PPh(2)) yielded the germanium(II) compounds LGeR [R = OtBu (1), 2-thienyl (2), N(H)Ar (3), PPh(2) (4)]. The reduction of (2-thienyl)(2)PCl with lithium afforded the diphosphane [(2-thienyl)(2)P](2) (5). The treatment of (2-thienyl)(2)PCl with LiAlH(4) or KHBtBu(3) led to the formation of (2-thienyl)(2)PH (6). The NHC-assisted reaction of LGeCl and 6 resulted in the isolation of LGeP(2-thienyl)(2) (7). This is the first example where NHC is used for eliminating HCl from compounds with P-H and Ge-Cl bonds. All solid products were characterized by elemental analysis, NMR and IR spectroscopy, and single-crystal X-ray structure determination.     

Reactions of (1R,2S)-1,2-di(2-furyl)-1,2-di(3-guaiazulenyl)ethane and (1R,2S)-1,2-di(3-guaiazulenyl)-1,2-di(2-thienyl)ethane with tetracyanoethylene (TCNE) in benzene: comparative studies on the products and their spectroscopic properties

Reactions of the title meso forms, (1R,2S)-1,2-di(2-furyl)-1,2-di(3-guaiazulenyl)ethane (1) and (1R,2S)-1,2-di(3-guaiazulenyl)-1,2-di(2-thienyl)ethane (2), with a two molar amount of TCNE in benzene at 25 °C for 5 h (for 1) and 48 h (for 2) under oxygen give new compounds, 2,2,3,3-tetracyano-4-(2-furyl)-8-isopropyl-6-methyl-1,4-dihydrocyclohepta[c,d]azulene (3) and 2,2,3,3-tetracyano-8-isopropyl-6-methyl-4-(2-thienyl)-1,4-dihydrocyclohepta[c,d]azulene (4), respectively, in 74 and 21% isolated yields. Comparative studies on the above reactions as well as the spectroscopic properties of the unique products 3 and 4, possessing interesting molecular structures, are reported and, further, a plausible reaction pathway for the formation of these products is described.     

Base cleavage of substituted [phenyl(2-thienyl)methyl]- and [phenyl(2-furyl)methyl]-trimethylsilane. Stabilization of carbanionic centres by 2-thienyl and 2-furyl groups

Rates of cleavage by NaOMEMeOH at 25°C have been determined for (2-thienyl)₂CHSiMe₃ and for the compounds Ph(2-thienyl)CHSiMe₃ and Ph(2-furyl)CHSiMe₃ and some of their derivatives with a substituent in the m- or p-position of the phenyl group or the 5-position of the heterocyclic group. The results indicate that the 2-thienyl and 2-furyl groups stabilize a carbanionic centre more effectively than a phenyl group, and the following approximate pK_a values can be derived: Ph₂CH₂, 33.4; Ph(2-thienyl)CH₂, 30.0; Ph(2-furyl)CH₂, 29.6; (2-thienyl)₂CH₂, 27.1. The effect of the 2-Cl substituent in the thiophen ring is close to that of the p-Cl substituent in the benzene ring, and the effects of the p-Me substituents on the benzene ring are very close to those of the 2-Me substituents on the thiophen or furan rings. The product and rate isotope effects (determined by use of MeOD) are consistent with separation of the carbanion in the rate-determining step.     

Thermal hydrothiolysis of di(2-thienyl)sulfide in the gaseous and liquid phase

At 500–600, di(2-thienyl)sulfide is converted to thiophene, thiophene thiols, dithienyls, and dithienothiophenes, and isomerized to 2,3-dithienylsulfide. Hydrogen sulfide accelerates these reactions significantly. In the liquid phase the thermal conversion of di(2-thienyl)sulfide takes place only with the participation of elemental sulfur or in the system sulfur-hydrogen sulfide. Thiophene and diethienothiophenes are not formed in this case, while isomerization occurs to a large degree. The observed thermal conversions of di(2-thienyl)-sulfide are based on the addition of thiyl radicals to the double bonds of the thiophene ring and to the sulfide sulfur atom.Communication 29 of the series High-temperature organic synthesis. For Communication 28 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1614–1619, December, 1986.     

Chloromethylation of substituted di(2-thienyl)methanes and the reductive desulfuration of some diamines of the thiopene series

The action of chloromethyl ether on di(2-thienyl)methane, 1, 1-di-(2-thienyl)ethane, 2, 2-di(2-thienyl)propane, 2, 5-bis(dimethyl-2-thienylmethyl)thiophene, and 1, 1, 1-tri(2-thienyl)ethane has given, respectively: 5-chloromethyl -2 -thienylthiophene, 1, 1-bis(5-chloro-methyl-2-thienyl)ethane, 2, 2-bis(5-chloromethyl-2-thienyl)propane, 2, 5-bis(dimethyl-5-chloromethyl-2-thienylmethyl)thiophene, 1-(2-thienyl)-1, 1-bis(5-chloromethyl-2-thienyl)-ethane, and the corresponding amines: 5-diethylaminomethyl-2-thienylthiophene, 1,1-Bis(5-diethylaminomethyl-2-thienyl)ethane, 2, 2-bis(5-aminomethyl-2 -thienyl)propane, 2, 2-bis(5-methylaminomethyl-2-thienyl)propane, 2, 5-bis(dimethyl-5-dimethylaminomethyl-2-thienylmethyl)thiophene, and 2, 8, 8, 14, 20, 20-hexamethyl-2, 14-diaza-3, 2, 3, 2--cyclotetrathiene. The reductive desulfonation over Raney nickel of the diacetyl derivatives of 2, 2-bis(5-aminomethyl-2-thienyl)propane and 2, 2-bis(5-methylaminomethyl-2-thienyl)propane has given the diacetyl derivatives of aliphatic amines.     

Convenient preparation of (4-iodophenyl)aryliodonium salts

The (4-iodophenyl)aryliodonium salts bis(4-iodophenyl)iodonium, (4-iodophenyl)(4-methoxy-phenyl)iodonium and (4-iodophenyl)(2-thienyl)iodonium, each with three different anions, were prepared using 4-iodo-1-[hydroxy(tosyloxy)iodo]benzene. These are suitable precursor molecules for electrophilic radiofluorination and other 4-iodophenylation reactions, whose products can subsequently serve as reagents for transition metal catalysed cross coupling and other metal organic reactions.     

Studies on C-heterocyclic tin compounds. The synthesis and spectral characterization of some thienyl tetraorganotin(IV) compounds

The synthesis of a series of tetraorganotin(IV) compounds containing selectively the 2-thienyl, 3-thienyl, 5-methyl-2-thienyl, 5-t-butyl-2-thienyl, 4-methyl-2-thienyl and 3-(2-pyridyl)-2-thienyl groups [L], of formula R_4-nSn[L]_n (R = Ph, p-tolyl, Me, cyclopentyl, cyclohexyl; n = 1–4) is reported. Features of structural interest deduced from ^119mSn Mössbauer and NMR (¹³C and ¹¹⁹Sn modes) spectra are considered.     

Chemical modification of poly(n-hexylsilane) - Synthesis of functional polysilanes bearing thienyl groups on the appended sila-alkyl side chains and their application in the generation and stabilization of silver nanoparticles

The linear polysilanes [{RR′₂Si(CH₂)_ySi(n-hex)}_x{HSi(n-hex)}_1−x]_n (1-4; R = 2-thienyl, R′ = H; R = Me, R′ = 2-thienyl; y = 2, 3) have been synthesized by hydrosilylation reaction between preformed poly(n-hexylsilane) and (2-thienyl)vinyldichlorosilane/allyl(2-thienyl)dichlorosilane/bis(2-thienyl)methylvinylsilane/allyl-bis(2-thienyl)methylsilane using AIBN as the free radical initiator. GPC analysis reveals a monomodal molecular weight distribution in each case with M_w = 2492-3280 and PDI = 1.18-1.44. The polysilane 1 (R = 2-thienyl, R′ = H, y = 2) acts as reducing agent towards silver tetrafluoroborate under mild conditions (cyclohexane, rt, 5 h) to afford spherical silver nanoparticles of size 8.4 ± 0.7 nm, as evident from the TEM and dynamic light scattering (DLS) studies. The silver nanoparticles in the polymer matrix exhibit surface plasmon absorption at 420 nm suggesting the donor-acceptor interaction between the thienyl group and the metal nanocluster surface. This stabilization effect provides long shelf life stability to the nanoparticles in solution with no sign of agglomeration even after three months.     

Synthesis and some transformations of 2-(2-thienyl)-1(3)H-imidazo[4,5-f] quinoline

2-(2-Thienyl)-1(3)H-imidazo{cm[4,5-f]}quinoline was synthesized by the Weidenhagen reaction of quinoline-5,6-diamine with thiophene-2-carbaldehyde. Its methylation in the system KOH-DMSO gave isomeric 1-methyl-2-(2-thienyl)-1H- and 3-methyl-2-(2-thienyl)-3H-imidazo{cm[4,5-f]}quinolines, the latter being the major product. The 3-methyl derivative was subjected to electrophilic substitution reactions (bromination, nitration, formylation, acylation, sulfonation). Depending on the conditions, electrophilic attack was directed at the thiophene or quinoline fragment or both these.     

Thermal transformations of allyl 2-thienyl sulfide and selenide

In the gas phase at 350–410C allyl 2-thienyl sulfide is converted to thiophene-2-thiol, di(2-thienyl) sulfide, and 2-methylthieno[2,3-b]thiophene. In the presence of acetylene thieno[2,3-b]thiophene is formed in addition to these products. Allyl 2-thienyl selenide is converted quantitatively to 2,3-dihydro-2-methylselenopheno[2,3-b]thiophene during fractional distillation in vacuo. Thiophene, di(2-thienyl) selenide, di(2-thienyl) diselenide, thiophene-2-selenol, and 2-methylselenopheno[2,3-b]thiophene are formed in addition to these compounds in the thermolysis of allyl thienyl selenide in the gas phase. In the presence of acetylene the thermal decomposition of allyl thienyl selenide is accompanied by the formation of selenophene.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1312–1316, October, 1991.     

Synthesis of Duloxetine Intermediate (S)-3-Chloro-1-(2-thienyl)-1-propanol with Liquid-Core Immobilized Candida pseudotropicalis 104

(S) -3-Chloro-1-(2-thienyl)-1-propanol was synthesized by the asymmetric reduction of 3-chloro-1-(2-thienyl)propanone with liquid-core immobilized Candida pseudotropicalis 104. The optimum time was 28?h for the re-cultivation of immobilized cells. The optimum film solvent for the liquid-core capsule was 0.3?% chitosan (M _w 1.0?×?10⁵). Conversion decreased with the increase of the liquid-core capsule diameter and with the addition of more substrates at the same reduction time. The immobilized cells show good reduction ability in a potassium phosphate buffer (pH 6.6~7.2). The material outside the spread speed of immobilized cells was not restricted when the shaking speed was higher than 160?r/min. Liquid-core immobilized cells can be reused 11 times. Compared with the batch reduction, the continuous reduction of 3-chloro-1-(2-thienyl)propanone in the membrane reactor with liquid-core immobilized cells as catalyst can relieve the inhibition from a high-concentration substrate. Conversion and enantiometric excess of (S)-3-chloro-1-(2-thienyl)-1-propanol reached 100?% and >99?% in a continuous reduction of 12?g/L 3-chloro-1-(2-thienyl)propanone for 10?days.     

Efficient Catalytic Activity of Transition Metal Ions in Vilsmeier–Haack Reactions with Acetophenones

Vilsmeier–Haack (VH) formylation reactions with acetophenones are sluggish in acetonitrile medium even at elevated temperatures. However, millimolar concentrations of transition metal ions such as Cu(II), Ni(II), Co(II), and Cd(II) were found to exhibit efficient catalytic activity in Vilsmeier–Haack Reactions with acetophenones. Reactions are accelerated remarkably in the presence of transition metal ions. The VH reactions followed second order kinetics and afforded acetyl derivatives under kinetic conditions also irrespective of the nature of oxychloride (POCl₃ or SOCl₂) used for the preparation of VH reagent along with DMF. On the basis of UV–vis spectroscopic studies and kinetic observations, participation of a ternary precursor [M(II) S (VHR)] in the rate‐limiting step has been proposed to explain the mechanism of the metal ion–catalyzed VH reaction.     

Synthesis and properties of novel poly(p-phenylenevinylene) copolymers for near-infrared emitting diodes

A series of novel near-infrared (NIR) electroluminescence (EL) copolymers based on a host poly(p-phenylenevinylene) (PPV) derivative of poly(2-methoxy-5-octyloxy-p-phenylenevinylene) (PMOPV) with different content of narrow band-gap (NBG) unit 4,7-bis(2-thienyl)-2,1,3-benzothiadiazolevinylene (DBTV) or 4,7-bis(2-thienyl)-2,1,3-benzoselenadiazolevinylene (TBSV) was prepared by Stille coupling reaction. All the copolymers are soluble in common organic solvents, most of which emit NIR light accompanied by gradually red-shifting with increasing the content of the NBG units. The peak EL emission of the copolymers with around 30% TBSV content is at about 800 nm.