A new route to annulated oligothiophenes

[reaction: see text] A new convenient method for the construction of thiophene-annulated thieno[2,3-b]thiophenes has been proposed. The key step of the method is ring closure of 10H-bisthienodithiocin-10-one by strong bases. The syntheses of two previously unknown annulated oligothiophenes, thieno[2,3-b]thieno[3',2':4,5]thieno[3,2-d]thiophene (1a) and thieno[3,2-b]thieno[2',3':4,5]thieno[3,2-d]thiophene (1b), have been described to illustrate the success of the method.     

Photochromic oligothienoacene derivatives with photo-switchable luminescence properties and computational studies

Photochromic thieno[3,2-b]thiophenes and dithieno[3,2-b:2',3'-d]thiophene with photo-switchable luminescence properties have been synthesized using a Suzuki cross-coupling reaction; their electronic structures, and photochromic and luminescence behaviour have also been studied.     

New approaches to the synthesis of functionally substituted pyrido[3′,2′:4,5]thieno[3,2-b]pyridines and the structure of the products obtained

Substituted pyrido,[3',2':4,5]thieno[3,2-b]pyndines were obtained by the reaction of 3-amino-2-benzoylthieno [2,3-b]pyridines with malononitrile and the reaction of 3-cyanopyridine-2(IH)-thiones with 2-aryl-3-bromo-I,I-dicyanopropene. 2-Amino-4-(4-bromophenyl)-7, 9-dimethyl-3-cyanopyrido [3',2':4,5]thieno[3, 2-b]-pyridine was used for the synthesis of a derivative of pyrido[3",2":4', 5']thieno[2',3':5,6]pyrido[2,3-d]-pyrimidine. The structure of these compounds was confirmed by spectral data and x-ray diffraction structural analysis.Deceased.     

Planar beta-linked oligothiophenes based on thieno[3,2-b]thiophene and dithieno[3,2-b:2',3'-d]thiophene fused units

A series of planar beta-linked oligothiophenes based on thieno[3,2-b]thiophene and dithieno[3,2-b:2',3'-d]thiophene fused units were synthesized. The optical data indicate a blue shift of the absorption maximum in comparison to the alpha-linked analogues due to cross-conjugation between fused rings. The crystal structures of 3,3'-bi(thieno[3,2-b]thiophene) and 3,3';6',3"-ter(thieno-[3,2-b]thiophene) reveal edge-to-face pi-stacked dimer motifs, whereas the crystal structure of 3,3'-bis(dithieno[3,2-b:2',3'-d]thiophene) consists of face-to-face pi-stacked molecules. [structure: see text]     

二氰基乙烯基并三噻吩的光谱行为

本文设计合成了两种二氰基乙烯基并三噻吩化合物,即2-二氰基乙烯基二噻吩并[3,2-b:2’,3-’d]噻吩(DCTT)与2-二氰基乙烯基二噻吩并[2,3-b:3’,2-’d]噻吩(DCST).研究了介质极性对吸收与发射光谱行为的影响,考察了化合物的分子结构与其发光能力的关系.溶剂效应显示化合物DCST随介质的极性增加,分子内电荷转移态(ICT)的荧光发射峰位红移现象更为明显,展示出较大的Stokes位移.化合物DCTT随介质的极性增加,发光行为表现出负的溶致变色效应,与"能级邻近效应"有关.溶剂效应说明了DCTT分子中并三噻吩部分给出电子的能力较弱,而DCST分子中的并三噻吩部分给出电子的能力较强,是导致二者ICT态的发光能力的差异的主要原因.     

Synthesis of new condensed derivatives of pyrano[4,3-<Emphasis Type="Italic">b</Emphasis>]thieno[3,2-<Emphasis Type="Italic">e</Emphasis>]pyridine and pyrido[3',2':4,5]thieno[3,2-<Emphasis Type="Italic">d</Emphasis>]pyrimidine

The reactions of 2-methyl (propyl) substituted 8,8-dimethyl-7,10-dihydro-4H,8H-pyrano[3",4":5',6']pyrido[3',2':4,5]thieno[3,2-d][1,3]oxazines with primary amines give 2-methyl (propyl) substituted 8,8-di- methyl-7,10-dihydro-8H-pyrano[3",4":5',6']pyrido[3',2':4,5]thieno[3,2-d][1,3]pyrimidin-4(3H)-ones or 3-acetyl-N-alkyl- and N-alkyl-3-butyrylamino-7,7-dimethyl-7,8-dihydro-5H-pyrano[4,3-b]thieno[3,2-e]- pyridine-2-carboxamides depending on steric hindrance in the amines.     

Synthesis, structures, and properties of disubstituted heteroacenes on one side containing both pyrrole and thiophene rings

A new series of ladder-type heteroacenes containing both pyrrole and furan rings, 5,6-disubstituted diindolo[3,2-b:4,5-b']thiophenes (DITs), were effectively synthesized from N-functionalized 3,3'-dibromo-2,2'-biindoles undergoing intramolecular cyclization with bis(phenylsulfonyl) sulfide and organolithium. Single-crystal X-ray results demonstrate that 5,6-dipropyldiindolo[3,2-b:4,5-b']thiophene (4b) forms a herringbone-type of packing motif and 5,6-di(p-tolyl)diindolo[3,2-b:4,5-b']thiophene (4d) forms a parallel packing motif. Both of them have S-S contacts, enhancing the electronic transport between molecules. Their photophysical properties suggest that the skeleton of diindolo[3,2- b:4,5-b']thiophene is more favorable to aggregate in solid than that of indolo[3,2-b]carbazole. The large band gaps and low-lying HOMO energy levels could result in much better stability.     

Synthesis of 3-Substituted Pyrido[4′,3′:4,5]thieno[2,3-d]pyrimidines and Related Fused Thiazolo Derivatives

New ethyl 3-(substituted)-4-oxo-2-thioxo-1,2,3,4,5,6,7,8-octahydropyrido[4',3':4,5]thieno-[2,3-d]pyrimidine-7-carboxylates ( 3a , b ), ( 6 ),( 11-13 ), ethyl 3-methyl-5-oxo-2,3,6,9-tetrahydro 5 H -pyrido[4',3':4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]pyrimidine-8(7H)-carboxylate ( 4 ), and ethyl 2-methyl-5-oxo-2,3,6,9-tetrahydro-5 H -pyrido[4',3':4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]-pyrimidine-8(7H)-carboxylate ( 8 ) have been synthesized from diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6-dicarboxylate 1. The structure of these compounds as well as their intermediates have been established by their spectral data.     

Synthesis of heterocyclic compounds possessing the 4H-thieno[3,2-b]pyrrole moiety

A series of novel heterocyclic combinatorial libraries containing 4H-thieno[3,2-b]pyrrole, thieno[2',3':4,5]-pyrrol[1,2-d][1,2,4]triazine and thieno[2',3':4,5]pyrrolo[1,2-a]pyrazine heterocyclic moieties were obtained by parallel solution-phase synthesis. Key steps include different reactions of initial alkyl 4H-thieno[3,2-b]-pyrrole-5-carboxylates, such as alkylation with alkylating agents; transformation of the carboxylate group into different reactive functionalities, followed by reactions with electrophilic species; intramolecular cyclizations; and amide bond formation. Simple manual techniques for parallel reactions were coupled with easy purification procedures to give high-purity final products.     

A CONVENIENT SYNTHESIS OF NEW PYRIDOTHIENOPYRIMIDIN-4 (3H) ONES AND PYRIDOTHIENOPYRIMIDIN-2, 4(1H, 3H) DIONES

New derivatives of 2-substituted pyrido[3′,2′:4,5]thieno[3,2-d]pyri-midin-4(3H) ones and 3-substituted pyrido[3′,2′:4,5]thieno[3,2-d]pyri-midin-2,4(1H,3H) diones have been prepared by base catalyzed cyclocondensation of ethyl-3-aminothieno[3,2-b]pyridine-2-carboxylate with aryl nitriles and aryl- or alkyl isocyanates respectively.     

Synthesis of 2-methylthie no [3,2-b]thieno-[2,3-d]thiazole

A new heterocyclic base — 2-methylthieno[3,2-b]thieno[2,3-d]thiazole — was synthesized by heating 2-acetamido-3-hydroxythieno[3,2-b]thiophene with phosphorus pentasulfide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1039–1041, August, 1976.     

Dianthra[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DATT): synthesis, characterization, and FET characteristics of new π-extended heteroarene with eight fused aromatic rings

A novel highly π-extended heteroarene with eight fused aromatic rings, dianthra[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DATT), was selectively synthesized via a newly developed synthetic strategy, fully characterized by means of single crystal X-ray structural analysis, and examined as an organic semiconductor in thin film transistors. Even with its highly extended acene-like π-system, DATT is a fairly air-stable compound with IP of 5.1 eV. Single crystal X-ray structural analysis revealed its planar molecular structure and the lamella-like layered structure with typical herringbone packing. Theoretical calculations of the solid state electronic structure based on the bulk single crystal structure suggest that DATT affords almost comparable intermolecular orbital couplings between HOMOs (t(HOMO)) with those of dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT), implying its good potential as an organic semiconductor for organic field-effect transistors. In fact, field-effect mobilities as high as 3.0 cm(2) V(-1) s(-1) were achieved with vapor-processed DATT-based devices, which is comparable with that of DNTT-based devices. The molecular ordering of DATT in the thin film state, however, turned out to be not completely uniform; as elucidated by in-plane and out-of-plane XRD measurements, the face-on molecular orientation was contaminated in the edge-on orientation, the former of which is not optimal for efficient carrier transport and thus could limit the mobility.     

1,3-Disubstitutedpyrazole-4-caboxaldehyde in Heterocyclic Synthesis: A Novel Synthesis of Pyridine-2(1H)-thione and Fused Nitrogen and/or Sulfur Heterocyclic Derivatives

Pyridine-2(1H)-thione 5 was synthesized from the reaction of 3-[3-(4-chlorophenyl)-1-phenyl-1H-pyrazol-4-yl]-1-phenylpropenone (3) and cynothioacetamide (4). Compound 5 reacted with halogented compounds 6a–e to give 2-S-alkylpyridine derivatives 7a–e, which could be in turn cyclized into the corresponding thieno[2,3-b]-pyridine derivatives 8a–e. Compound 8a reacted with hydrazine hydrate to give 9. The latter compound reacted with acetic anhydride (10a), formic acid (10b), acetic acid, ethyl acetoacetate, and pentane-2,4-dione to give the corresponding pyrido[3′,2′:4,5]thieno-[3,2-d]pyrimidine 13a,b, pyrazolo[3′,4′:4,5]thieno[3,2-d]pyridine 14 and thieno[2,3-b]-pyridine derivatives 18 and 20, respectively. Alternatively, 8c reacted with 10a,b and nitrous acid to afford the corresponding pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine 24a,b and pyrido[3′,2′:4,5]thieno[3,2-d][1,2,3]triazine 26 derivatives, respectively. Finally compound 5 reacted with methyl iodide to give 2-methylthiopyridine derivative 27, which could be reacted with hydrazine hydrate to yield the corresponding pyrazolo[3,4-b]-pyridine derivative 29.     

A NOVEL SYNTHESIS OF 2-SUBSTITUTED-4H-THIENO [2,3-d][1,3] OXAZIN-4-ONE AND 2,3-DISUBSTITUTED THIENO [2,3-d]PYRIMIDIN-4(3H)-ONE DERIVATIVES

Abstract

The synthesis of acetic 2-{[1-methyl-2-(4-oxo-5,6,7,8-tetrahydro-4H-benzo [4,5]-thieno [2,3-d] [1,3-oxazin-2-yl)ethylidene]amino}-4,5,6,7-tetrahydrohenzo[b]thiophene ?3-carboxylic acid anhydride 5 and 2-(oxopropyl)-5,6,7,8-tetrahydro-4H-benzo-[4,5] thieno[2,3-d][1,3]oxazin-4-one 7, has been achieved in three steps from ethyl 2-amino-4,5,6,7-tetrahydrobenzo(b]thiophene-3-carboxlate 1 via the reaction with ethyl acetoacetate followed by hydrolysis and acetic anhydride-induced cyclization. The 2-substituent in compound 5 has two functional groups i.e. active methylene and acid anhydride which are suitably located for intramolecular transformation. Thermal and/or base catalyzed intramolecular cyclization of 5 afforded 2-(4-acetoxy-(hydroxyl)-2-methyl-5,6,7,8-tetrahydrobenzo[4,5] thieno[2,3-b]pyridin-3-yl)-5,6,7,8- tetrahydro-4H-benzo[4,5]thieno[2,3-d] [1,3]oxazin-4-one 10 and 9 respectively. Treatment of 5 with hydrazine hydrate, aromatic and/or heterocyclic amines induced the same intramolecular cyclization with a concomitant oxazine-pyrimidine interconversion to give 3-amino(aryl or heteryl)-2-(4-hydroxy-5,6,7,8-tetrdhydrobenzo-[4,5]thieno[2,3-b]pyridin-3-yl)-3,4,5,6,7,8-hexahydrobenzo[4,5] thieno[2,3-d] pyrimid in-4-one 11–14 respectively.     

两种非对称芳基二噻吩并[2,3-b:3',2'-d]噻吩的合成与光谱特性

合成了两种非对称芳基取代的并三噻吩化合物.以2-溴-5-三甲基硅-二噻吩并[2,3-b:3',2'-d]噻吩为原料,经脱除四甲基硅烷(TMS)和Suzuki偶联两步反应制备了2-噻吩基二噻吩并[2,3-b:3',2'-d]噻吩,总产率为67.4%;以2-苯基二噻吩并[2,3-b:3',2'-d]噻吩为原料,经N-溴代琥...     

Luminescent digold ethynyl thienothiophene and dithienothiophene complexes; their synthesis and structural characterisation

A series of protected and terminal dialkynes with extended pi-conjugation through the fused oligothienyl linker unit in the backbone, 2,5-bis(trimethylsilylethynyl)thieno[3,2-b]thiophene 1a, 5,5'-bis(trimethylsilylethynyl)dithieno[3,2-b:2',3'-d]thiophene 1b, 2,5-bis(ethynyl)thieno[3,2-b]thiophene 2a, 5,5'-bis(ethynyl)dithieno[3,2-b:2',3'-d]thiophene 2b, has been synthesized and characterised. The digold alkynyl complexes [(Ph3P)Au(C[triple bond]C)(C6H2S2)(C[triple bond]C)Au(PPh3)] 3a and [(Ph3P)Au(C[triple bond]C)(C8H2S3)(C[triple bond]C)Au(PPh3)] 3b have then been prepared by the reaction of two equivalents of Ph3PAuCl and a methanolic KOH solution of 1a and 1b, respectively. The complexes have been characterised spectroscopically. The crystal structures show that the gold centres adopt a linear two-coordinate geometry appropriate for Au(i) complexes. Within the crystals adjacent molecules are linked by Au...S intermolecular interactions in the range 3.48-3.89 A, but there are no short Au...Au contacts. The absence of Au...Au interactions in solution is confirmed by UV/visible absorption and emission spectroscopy, the spectra being dominated by ligand-centred pi-pi* interactions.     

Functional derivatives of thiophene

A method is proposed for the synthesis of 5-acylamino-2,3-dimethylthiophene-4-carbaldehydes and 5-acylamino-2,3-tetramethylenethiophene-4-carbaldehydes by the formylation of the corresponding thiophenes using the Vilsmeier reaction. From the formyl derivatives obtained, previously unaccessible derivatives of thieno[2,3-b]pyridine, thieno[2,3-d]pyrimidine, and thieno[3′,2′∶5,6]pyrido[2,3-d]-pyrimidine have been synthesized.     

Synthesis and Reactions of Some New Heterocyclic Compounds Containing Cycloalka[e]thieno[2,3‐b]pyridine Moiety

Hydrolysis of ethyl 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxylates ( 3a-d) gave the corresponding o-aminocarboxylic acids 4a-d . Heating the latter compounds ( 4a-d) with acetic anhydride furnished the oxazinone derivatives 5a-d which, in turn, underwent recyclization reaction to give the corresponding pyrimidinones 6a-d upon treatment with ammonium acetate in acetic acid. Reaction of 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides ( 3f,h ) with triethyl orthoformate gave pyrimidinone derivatives 7a,b . Reaction of 3-amino-4-phenyl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides 3e,h with aromatic aldehydes furnished tetrahydropyridothienopyrimidinones 8a-d . Chlorination of 7a,b and 6a-d by using phosphorous oxychloride produced 4-chlorocycloalka[5′,6′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine derivatives 9a-f which were used as key intermediates in the synthesis of several new cycloalkapyrido-thienopyrimidines 10a-f ˜ 14a-f . Moreover, some cycloalkapyridothienotriazinones 15a,b-17a,b were synthesized.     

An efficient synthesis of novel pyridothieno-fused thiazolo[3,2-a]pyrimidinones via Pictet–Spengler reaction

An efficient method for the synthesis of novel pyrido[3',2':4',5']thieno[3',2':2,3]pyrido [4,5:d][1,3]thiazolo[3,2-a]pyrimidine-4-one derivatives (5) has been developed using a Pictet-Spengler reaction between 2-(3-aminothieno[2,3-b]pyridin-2-yl)thiazolo[3,2-a] pyrimidin-5-one (3), which could be obtained from the condensation of 7-(chloromethyl)-5H-thiazolo[3,2-a]pyrimidin-5-one (1) with 3-cyanopyridine-2-thione (2) via Thorpe-Ziegler isomerization, and aromatic aldehydes under NH₂SO₃H as catalysis in good yields.     

A Convenient Synthesis for Some New Pyrido[4′,3′:4,5]thieno[2,3-d]pyrimidines and Related Fused 1,2,4-Triazolo and 1,3,4-Thiadiazolo-derivatives

Diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6 dicarboxylate 1 is a convenient and useful starting matrial for the constructions of heterocyclic systems. It was utilized to synthesize derivatives of the novel heterocyclic systems pyrido[4',3':4,5]thieno[2,3-d]pyrimidine 4 , 10 , pyrido[4',3':4,5]thieno[2,3-d]-[1,2,4]triazolo[1,5-a]pyrimidine 7 , 11a-e and pyrido[4',3':4,5]thieno[2,3-d][1,3,4]thiadiazolo[3,2-a]pyrimidine 12-14 .