On the syntheses and some reactions of bis- and tris(methylthio)thiophenes

Reaction between various thienyllithium derivatives and dimethyl disulfide has been used for the preparation of 2,5-, 2,3-, and 3,4-bis(methylthio)thiophenes, as well as 2,3,4- and 2,3,5-tris(methylthio)thiophenes. Bromination of (methylthio)thiophenes with N-bromosuccinimide was found to be most convenient for the preparation of brominated (methylthio)thiophenes such as 3-bromo-2,5-bis(methylthio)- and 5-bromo-2,3-bis(methylthio)thiophene, 3,4-dibromo-2,5-bis(methylthio)-, 2,5-dibromo-3,4-bis(methylthio)- and 2,3-dibromo-4,5-bis(methylthio)thiophene as well as 3-bromo-2,4,5-tris(methylthio)thiophene. The reaction of methylthio substituted thienyllithium derivatives with methyl chloroformate was used for the syntheses of methyl methylthio substituted thiophenecarboxylates and using 1/3 of an equivalent for the direct preparation of methylthio substituted 3-thienylcarbinols as tris[2,4,5-tris(methylthio)-3-thienyl]carbinol.     

Electrochemical preparation of polythiophene via 2,5-bis(trimethylsilyl)thiophene

Electrochemical polymerization of 2,5-bis(trimethylsilyl) thiophene produced highly conducting films which showed infrared spectra, visible-near infrared absorption spectra, and cyclic voltammograms identical to films prepared from thiophene. Elemental analysis indicated that almost all silicon atoms were eliminated during the electrochemical polymerization. However, scanning electron microscopy showed a morphological difference between the films from 2,5-bis(trimethylsilyl)thiophene and from thiophene. The electrochemical polymerization of bis(2-thienyl)dimethylsilane, 1,2-bis(2-thienyl)tetramethyldisilane, and bis(2-thienyl)diphenylsilane also produced polythiophene films having unique morphologies quite different from the conventional ones. These findings indicate that these electrochemical procedures must be useful for preparation of new conjugated polymers. © 1992 John Wiley & Sons, Inc.     

Synthesis and Crystal Structure of 2,5—Bis（morpholino）—3,4—bis（p—chlorophenyl）thiophene

1 INTRODUCTION -Thiocarbonylthioformamide synthesized in 1980[1, 2] is a class of stable and almost unexplored compounds[3]. We have reported the reaction of - thiocarbonylthioformamides in our previous paper[4]. Here, we will report a novel synthesis of 2 by the reaction of 1 and trimethyl phosphite in refluxing xylene. In order to determine the structure of 2, X- ray crystallographic study was carried out. 2 EXPERIMENTAL 2. 1 Preparation of the title compound Trimethyl phosph…     

Synthesis of 2,5 -Bis(4-methyl-2-thienyl)thiophene and 2,5-Bis(4-methyl-2-thienyl)pyrrole

Syntheses of 2,5-bis(4-methyl-2-thienyl)thiophene 3 and 2,5-bis(4-methyl-2-thienyl)pyrrole 4 are described. The key step involves Stetter reaction between 4-methyl-2-thiophenecarboxaldehyde and divinyl sulfone. Cyclizaton of the resulting 1,4-bis-(4-methyl-2-thienyl)-1,4-butanedione 2 with Lawesson's reagent gives 2,5-bis(4-methyl-2-thienyl)thiophene 3, whereas condensation with ammonium acetate provides the 2,5-bis(4-methyl-2-thienyl)pyrrole 4.     

Synthesis of 3-Cyano-4,6-bis(methylthio)pyrazolo[3,4-d]pyrimidine 1-riboside

3-Cyano-4,6-bis(methylthio)pyrazolo[3,4-d]pyrimidine was synthesized by cyclization of 3,4-dicyano-5-aminopyrazole with CS₂ in pyridine with subsequent Dimroth rearrangement and methylation of the resulting 3-cyano-4,6-dimercaptopyrazolo[3,4-d]-pyrimidine with methyl iodide. Glycosylation of the product by fusion with 1,2,3,5-tetra-O-acetyl--D-ribofuranose in the presence of iodine gave 1-(2,3,5-tri-O-acetyl--D-ribofuranosyl)-3-cyano-4,6-bis(methylthio)pyrazolo[3,4-d]pyrimidine, the deacetylation of which with a 1% solution of hydrogen chloride in methanol led to 3-cyano-4,6-bis(methylthio)pyrazolo[3,4-d]pyrimidine 1-fiboside. The structures of the compounds were established by IR, UV, circular dichroism, PMR, and ¹³NMR spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1687–1692, December, 1979.Original article submitted March 29, 1979.     

Synthesis, structures and comparative electrochemical study of 2,5-bis(trimethylsilylethynyl)thiophene coordinated cobalt carbonyl units

The reaction between 2,5-bis(trimethylsilylethynyl)thiophene and Co₂(CO)₈ or Co₂(CO)₆(X), (X = dppa, dppm), gave rise to the formation of substituted ethynylcobalt complexes containing one or two Co₂(CO)₆ or Co₂(CO)₄(X) units, 2-[Co₂(CO)₄(X){μ₂-η²-(SiMe₃)C₂}]-5-(Me₃SiCC)C₄H₂S (X = 2CO (1), dppa (3) or dppm (4)) and 2,5-[Co₂(CO)₄(X){μ₂-η²-SiMe₃C₂}]₂C₄H₂S (X = 2CO (2), dppa (5) or dppm (6)). Desilylation of the non-metallated and metallated alkynes in 3, 4 and 6 occurred on treatment with KOH and tetrabutylammonium fluoride to give 2-[Co₂(CO)₄(μ-X){μ₂-η²-SiMe₃C₂}]-5-(CCH)C₄H₂S (X = dppa (7), dppm (8)) and 2,5-[Co₂(CO)₄(μ-dppm){μ₂-η²-HC₂}]₂C₄H₂S (9), respectively. Crystals of 6 suitable for single-crystal X-ray diffraction were grown and the molecular structure of this compound is discussed. A comparative electrochemical study of all these complexes is presented by means of the cyclic and square-wave voltammetry techniques.     

Applications of 2,5-bis(trimethylstannyl)thiophene. Synthesis of 3-methoxy-17α,-(5-iodothien-2-yl)-estra-1,3,5(10)trien-17β-ol

Monotransmetallation of 2,5-bis(trimethylstannyl)thiophene followed by the addition of estrone 3-methyl ether and iodine yields 3-methoxy-17α,-(5-iodothien-2-yl)estra-1,3,5(10)trien-17β-ol.     

Synthesis and transformation of sulfides of the thiophene series. 34. Quantum-chemical studies of the specificity of electrophilic attack and isomerization under C-protonation conditions in the alkylmercaptothiophene series

2-Methoxy-5-methylthiothiophene, 2,5-bis(methylthio)thiophene, and all of their possible C-protonated forms ( complexes) were subjected to calculations by the self-consistent-field (SCF) MO LCAO method within the CNDO/2 (complete neglect of differential overlap/2) valence approximation. The results obtained were used to explain the peculiarities of the behavior of these compounds in electrophilic-substitution reactions (Vilsmeier formylation and acetylation). It is shown that the most preferred sites of electrophilic attack in both compounds are the 3 and 5 positions, while the least active site is the 2 position in 2-methoxy-5-methylthiophene, as a result of which one should not observe either migration or splitting out of an OCH₃ group, in agreement with the available experimental data. The energetics of the secondary transformations of the complexes formed in the reaction, viz., isomerization and elimination of the SCH₃ ⁺ group, were estimated.See [1] for Communication 33.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1035–1039, August, 1981.     

Reaction of arylsulfonyl compounds with excess organolithium reagent 10. Opening of the thiophene ring inβ-lithium derivatives of 2,5-bis(tert-butylsulfonyl)thiophene

Conclusions Opening of the thiophene ring is observed in the lithium derivatives of 2,5-bis(t-butylsulfonyl)thiophene, resulting in the formation of functionally substituted dienes of their transformation products.See [1] for communication 9.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1367–1370, June, 1977.     

Synthesis of benzoates of 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis-(2,5-dimethyl-4-hydroxypiperidino)-2-butyne

1,4-Bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butyne (II and III) were obtained by the action of 1,4-dibromo-2-butene and 1,4-dibromo-2-butyne on the form of 2,5-dimethyl-4-piperidol (I). The benzoates (IV and V) were obtained by acylation of II and III with benzoyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 352–353, March, 1971.     

Polyhydrazides based on 2,5-bis(4-carboxymethylene phenyl)-3,4-diphenyl thiophene

A series of polyhydrazides was synthesized from a novel dicarboxylic acid, 2,5-bis(4-carboxymethylene phenyl)-3,4-diphenyl thiophene (V) and or terephthalic acid and isophthaloyl or terephthaloyl dihydrazide by Yamazaki’s phosphorylation method using triphenyl phosphite as condensing agent. Polyhydrazides were characterized by IR spectroscopy solubility, viscosity, thermogravimetric analysis and X-ray diffraction studies.The polymers were obtained in quantitative yields. Polyhydrazides had viscosities in the range of 0.25-0.70 dL/g. The polymers derived from novel diacid (V) showed enhanced solubility than the polymers derived from terephthalic acid, which may be attributed to the presence to bulky pendant phenyl group and methylene spacer group in the polymer backbone. Polymers were soluble in most of the common aprotic polar solvents. Polyhydrazides showed considerable weight loss in the temperature range of 300-400 °C which is due to the cyclodehydration, leading to the formation of corresponding polyoxadiazoles. They showed T_max in between 500 and 600 °C which is essentially the decomposition of the polyoxadiazoles. X-ray diffraction studies showed that polyhydrazides were amorphous in nature.     

Synthesis and properties of 4′,5′-bis(methylthio)-4,5-bis(2-pyridylethynyl)tetrathiafulvalene and its copper complexes

Synthesis of redox-active bis-pyridine ligand, 4′,5′-bis(methylthio)-4,5-bis(2-pyridylethynyl)tetrathiafulvalene (1) has been carried out in moderate yield starting from the corresponding diiodide. Bis(pyridylethynyl)-TTF 1 forms 1:1 complexes with Cu(I) and Cu(II) salts. Occurrence of the charge transfer from the TTF moiety to the copper atom was found to depend on the environment of copper atom.     

25,27-dithiasapphyrin and pyrrole-inverted isomer of 21,23-dithiaporphyrin from condensation of pyrrole and 2,5-bis(p-tolylhydroxymethyl)thiophene

[see structure]. A novel aromatic isomer of 5,10,15,20-tetra(p-tolyl)-21,23-dithiaporphyrin (S2TTP) with an inverted pyrrole ring, 5,10,15,20-tetra(p-tolyl)-2-aza-21-carba-22,24-dithiaporphyrin (S2CTTP), and 5,10,15,20-tetra(p-tolyl)-25,27-dithiasapphyrin (25,27-S2TTSH), have been obtained by a condensation of 2,5-bis((p-tolyl)hydroxymethyl)thiophene and pyrrole. A conformational equilibrium, unique in a sapphyrin class, between two S(27)-thiophene-flipped and planar structures of neutral 25,27-S2TTSH was detected by 1H NMR.     

2,5-Bis-(butyltelluro) thiophene as a convenient precursor for the synthesis of 2,5-bis-(acetylenic) thiophenes

Both symmetrically and unsymmetrically substituted 2,5-bis-(acetylenic) thiophene derivatives were obtained in good yields under mild conditions through palladium-catalyzed cross coupling reaction of 2,5-bis-(butyltelluro) thiophene 2 and terminal alkynes. The methodology represents a general and efficient protocol for carrying out the synthesis of thiophene derivatives with potential biological activities.     

Synthesis and polymerization of 2,5-dimethylene-2,5-dihydrothieno[3,2-b]thiophene derivatives: The structure and reactivity of quinonoid monomers

Novel 2,5-dimethylene-2,5-dihydrothieno[3,2-b]thiophene derivatives such as 2,5-bis[di(ethylthio)methylene]-2,5-dihydrothieno[3,2-b]thiophene ( 4b ) and 2,5-bis[cyano(ethylthio)methylene]-2,5-dihydrothieno[3,2-b]thiophene ( 4c ) were successfully synthesized as isolable crystals. Polymerization behavior of 2,5-bis(dicyanomethylene)-2,5-dihydrothieno[3,2-b]thiophene ( 4a ), 4b , and 4c was investigated. 4a , 4b , and 4c are not homopolymerizable with any initiators and also not copolymerizable with vinyl monomers such as styrene (St), methyl methacrylate, and acryronitrile except for an alternating copolymerization of 4a with St. 4a , 4b , and 4c did not copolymerize with 7,8-bis(butoxycarbonyl)-7,8-dicyanoquinodimethane (BCQ) as a highly conjugated comonomer and instead only homopolymer of BCQ was obtained, indicating that they are much less reactive than BCQ. To obtain the relative reactivity among 1c , 2c , and 4c , the rate of addition reaction of 2,2′-azobis(isobutyronitrile) (AIBN) with 4c was compared with those of AIBN with 7,8-bis(ethylthio)-7,8-dicyanoquinodimethane ( 1c ) and with 2,5-bis[cyano(ethylthio)methylene]-2,5-dihydrothiophene ( 2c ) by NMR spectroscopy and analyzed with the first-order kinetics. The relative reactivity among 1c , 2c , and 4c was found to be as follows: 1c > 4c > 2c . The relationship between structure and reactivity for the quinonoid compounds was discussed. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3027–3039, 1999     

Photochromic dihetarylethenes. 10. Photochromic 1,2-bis[2-(benzothiazol-2-yl)-3-thienyl]- and 1,2-bis[2-(benzothiazol-2-yl)benzothiophen-3-yl]ethenes

Dithienylethenes containing the thiophene rings with benzothiazolyl substituents in position 2 were synthesized. 1,2-Bis[2-(benzothiazol-2-yl)benzothiophen-3-yl]hexafluorocyclopentene and 1,2-bis[2,5-di(benzothiazol-2-yl)-3-thienyl]hexafluorocyclopentene possess photochromic properties. The open forms of 1,2-bis(2-benzothiazolylhetaryl)ethenes fluoresce, but introduction of the benzothiazole rings into dihetarylethenes significantly lowers the fatigue resistance of photochromes and favors thermal reversibility.     

Spectral and quantum-chemical study of some heteroanalogs of 1,4-bis(5-phenyl-2-azolyl)benzenes

The effect of structural changes in the molecules of thiophene and furan analogs of 1,4-bis(5-phenyl-2-azolyl)benzenes on their electronic spectra was studied by the MO LCAO method within the -electron approximation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 817–821, June, 1991.     

Metallation reactions. XXXVI. A study on the metallation of (methylthio)‐ and (methylsulfonyl)thiophenes

Methylthio‐ and methylsulfonyl thiophenes were polymetallated by n‐buthyllithium and superbase (LICKOR) in one‐step. 2 ‐(Methylthio)thiophene was bimetallated in 5 and in alpha to the methylthio sulfur atom by superbase. 3‐(Methylthio)thiophene was bimetallated in both 2 and 5 positions by the organolithium and trimetallated in these two positions and in alpha to the thioethereal sulfur atom by superbase. 3‐(Methylsulfonyl)thiophene was bimetallated in 2 and in alpha to the sulfonyl sulfur atom by the organolithium while the 2 ‐(methylsulfonyl)thiophene underwent degradation in the same 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--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.     

2,5-Dimethyl-3,4-bis[(2R,5R)-2,5-dimethylphospholano]thiophene: first member of the hetero-DuPHOS family

[reaction: see text] The 2,5-dimethyl-3,4-bis[(2R,5R)-2,5-dimethylphospholano]thiophene (UlluPHOS), a new thiophene-based analogue of (R,R)-1,2-bis(phospholano)benzene (Me-DuPHOS), was synthesized, geometrically and electronically characterized, and employed as ligand of Rh and Ru in some standard hydrogenation reactions of prostereogenic functionalized carbon-carbon and carbon-oxygen double bonds. The synthesis of UlluPHOS is much easier than that provided for Me-DuPHOS. UlluPHOS and Me-DuPHOS display very similar geometries, while the electronic availability of the former is higher than that exhibited by the latter. The Rh and Ru complexes of UlluPHOS produced excellent enantiomeric excesses (98.9-99.5%) in the hydrogenation of N-acetyl-alpha-enamino acids and reaction rates higher than those found when employing the analogous complexes of Me-DuPHOS.