Palladium-Catalyzed C-H Bond Functionalization of Benzo[1,2-b : 4,5-b′]dithiophene-4,8-dione: A One Step Access to 2-Arylbenzo[1,2-b : 4,5-b′]dithiophene-4,8-diones

The reactivity of benzo[1,2-b : 4,5-b′]dithiophene-4,8-dione in Pd-catalyzed C−H arylation was investigated. Using aryl bromides as aryl source in the presence of carbonate bases in 1,4-dioxane, the mono-C2-arylated benzo[1,2-b : 4,5-b′]dithiophene-4,8-diones were regioselectively obtained. This procedure allowed to introduce both electron-rich and electron-poor aryl substituents on the benzo[1,2-b : 4,5-b′]dithiophene-4,8-dione unit. These conditions were also effective for the coupling with 1-bromonaphthalene, 9-bromophenanthrene as well as aryl bromides bearing synthetically useful nitrile, chloro and methoxy substituents. The photophysical properties of representative arylated compounds have been performed by joint experimental and theoretical studies.     

Synthesis of substituted 4-hydroxy-1H-thieno[2,3-b;4,5-b′]dipyridin-2-ones

Substituted 4-hydroxy-1H-thieno[2,3-b;4,5-b′]dipyridin-2-ones were prepared by the reactions of 3-cyanopyridine-2(1H)-thiones with alkyl 4-chloroacetoacetates and by intramolecular cyclization of alkyl 4-(2-pyridylthio)acetoacetates or alkyl 3-(3-aminothieno[2,3-b]pyridin-2-yl)-3-oxopropionates under the action of bases.     

A Near-infrared Non-fullerene Acceptor with Thienopyrrole-expanded Benzo[1,2-b:4,5-b′]dithiophene Core for Polymer Solar Cells

A near-infrared non-fullerene acceptor(NFA) BDTIC, based on thienopyrrole-expanded benzo[1,2-b:4,5-b′]dithiophene unit(heptacyclic S,N-heteroacene) as core, is designed and synthesized. The aromatic pyrrole ring with strong electron-donating ability in the core enhances the intramolecular charge transfer effect, finely tunes the optical bandgap and absorption profile of BDTIC, and thus results in a narrowed optical bandgap(E_g~(opt)) of 1.38 eV and a near-infrared absorption to 900 nm. When BDTIC is paired with donor polymer PBDB-T to fabricate organic solar cells, the optimized device achieves a best power conversion efficiency of 12.1% with a short-circuit current density of 20.0 mA·cm~(-2) and an open-circuit voltage of 0.88 V. The photovoltaic performance benefits from the broad absorption, weak bimolecular recombination, efficient charge separation and collection, and favorable blend morphology. This work demonstrates that thienopyrroleexpanded benzo[1,2-b:4,5-b′]dithiophene unit(heptacyclic S,N-heteroacene) is a promising building unit to construct high-performance NFAs by enhancing the intramolecular charge transfer effect, broadening absorption as well as maintaining good intermolecular stacking property.     

Synthesis and characterization of NLO chromophore with benzo [1,2-b:4,5-b′]dithiophene unit as π-electron bridge

A novel chromophore BDT–TCF with benzo[1,2-b:4,5-b′]dithiophene (BDT) unit as electron bridge was synthesized and characterized by UV–vis, NMR spectroscopy, and thermal analysis. It is the first time that BDT unit was introduced into NLO materials. The chromophore showed excellent solubility in most common solvents, and good thermal stability for practical applications. The second order nonlinear optical effect was measured by hyper Rayleigh scattering method. The diagonal hyperpolarizability β_zzz of BDT–TCF was 8.2 × 10^?28 and 9.3 × 10^?29 esu in THF solvent and in PMMA polymer matrices, respectively. The potential NLO response indicates that BDT unit is a promising π-electron bridge and an excellent candidate for nonlinear optical devices.     

3,7-DICHLORO-2,6-DI-(4,4′-BUTYL-AMIDINO)BENZO[2,1-b:4,5-b′]DITHIO-PHENE DIHYDROCHLORIDE AS POTENTIAL ANTI-HIV AGENT

The multistep synthesis of substituted diamidine of benzodithiophene structure as soluble salt is described. On this way was prepared the compound in title; 3,7-dichloro-2,6-di-(4,4′-n-butyl-amidino)benzo[2,1-b:4,5-b′]dithiophene dihydrochloride 6a. Prepared compound could serve as new intercalator on DNA in the HIV infection.     

Near-Infrared Nonfullerene Acceptors Based on 4H-Cyclopenta[1,2-b:5,4-b′]dithiophene for Organic Solar Cells and Organic Field-Effect Transistors

The development of nonfullerene small molecular acceptors (NF-SMAs) has dominated the improvement of efficiencies for organic solar cells and the near-infrared (NIR) absorption is the primary feature of NF-SMAs compared with fullerene derivatives. In this article, a series of acceptor-donor-acceptor-structured NF-SMAs (named CPICs ) containing 4H-cyclopenta[1,2-b : 5,4-b′]dithiophene (CPDT) electron donor and F-substituted 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (2FIC) as electron acceptor were designed and synthesized. With the increase of CPDT units, the elongated conjugations broadened the absorption range of the acceptors and tuned their energy levels sequentially. Therefore, their charge-transporting polarities switched from electron-only type to bipolar mode in organic field-effect transistors. Moreover, these changes also influenced the voltages, current densities, and eventual PCEs of their corresponding cells. When blending with PBDB-T, a champion efficiency of 10.01% was achieved in CPIC-2 based cells. This work demonstrated the importance of absorptions, suitable energy levels and charge transports in improving the efficiencies of organic solar cells.     

苯并咪唑并[2,1-b]噻唑衍生物的合成

以2-巯基咪唑类化合物为原料,室温下与含有端基炔的二芳基高碘盐反应,一步合成苯并咪唑并[2,1-b]噻唑衍生物,其结构经¹H NMR、¹³C NMR、 单晶X-衍射和HR-MS表征。在最佳反应条件［n(2-巯基苯并咪唑)/n(二芳基高碘盐)=1/1,二氯甲烷为溶剂,反应12 h］下,目标化合物的产率最高为84%。同时对该反应的机理进行了详细探讨,并采用MTT法研究了目标化合物对人肝癌细胞（HepG2）生长情况的影响。结果表明：当浓度为4 μg/mL时,化合物3b具有较强的抑制HepG2细胞增殖的活性,抑制率为52%。     

顺式-四氢环丁烷[1,2-b:3,4-b′]骈二吡啶-四羧酸乙酯的合成及晶体结构

研究了由3,5-二羧酸乙酯-1,4-二氢吡啶光二聚合成顺式二聚体的反应,培养出了顺式二聚体的单晶,并表征了单晶的晶体结构.结果表明,合成的顺式二聚体晶体为单斜晶系,空间群P2(1)/c,晶胞参数为:a=1.193 7(2)nm,b=2.091 3(4)nm,c=0.976 3(2)nm,α=90.00°,β=108.46(3)°,γ=90.00°,V=2.311 9(8)nm3,Z=4,μ=0.099mm-1.     

A new phenanthro [2,3-b] furan from Pleione bulbocodioides

A novel phenanthro[2,3-b]furan 1,named(3-hydroxy-9-(4′-hydroxy-3′-methoxypheny1)-11-methoxy-5,6,9,10-tetrahydro- phenanthro[2,3-b]furan-10-yl)methyl acetate,and two known phenolic compounds were isolated from the tubers of Pleione bulbocodioides(Franch.)Rolfe.Their structures were elucidated by spectroscopic methods.     

异色满并[4,3-b]喹啉衍生物的合成

早在1931年,Hetherington等从念珠状曲菌(Aspergillus Cand inin)和土曲菌(Asperillus tereus)等菌类中分离出带有异色满(Isochroman)环系结构的左旋抗菌素橘霉素(C itrinin),后来又相继发现诸多带有异色满环系的天然产物[1-3],新近在软木木质素中也发现了多种具有异色满结构的     

Synthesis of Bisindolylindeno[1,2-b]quinoxaline and Bisindolylindeno[3,4-b]pyrazine with Poly(N,N′-dibromo-N-ethylnaphthyl-2,7-disulfonamide)

Poly(N,N′-dibromo-N-ethylnaphthyl-2,7-disulfonamide) (PBNS) as novel reagent was synthesized. Bisindolylindeno[1,2-b]quinoxaline and bisindolylindeno[3,4-b]pyrazine derivatives were synthesized in a simple and efficient method from the three-component condensation reaction of indole, indane-1,2,3-trione, and diamine aromatic compounds by PBNS under solvent-free conditions at 80 °C in good to excellent yields, short reaction times, and a simple procedure for new derivatives.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications^® for the following free supplemental resource(s): Full experimental and spectral details.]     

Synthesis of new conjugated copolymers containing 4,8-bis(dodecyloxy)benzo[1,2-b:4,5-b′]dithiophene/5,7-bis(3,4-diethylthien-2-yl)-2,3-diphenylthieno[3,4-b]pyrazine and 4,8-bis(dodecyloxy)benzo[1,2-b:4,5-b′]dithiophene/4,6-di(3,4-diethylthien-2-yl)-thieno[3,4-c][1,2,5]thiadiazole derivatives for photovoltaic applications

Two new donor-acceptor narrow-band-gap photovoltaic copolymers containing various electron-acceptor functional groups, such as thienopyrazine and thienodithiazole derivatives, are synthesized under the conditions of the Suzuki polycondensation reaction and characterized via ¹H NMR spectroscopy and GPC. The optical, electrochemical, and photovoltaic properties of the polymers are examined in detail. Both copolymers have good solubilities, high thermal stabilities, broad absorption regions (350–950 nm), relatively low levels of the highest occupied molecular orbital (?5.01 and ?5.02 eV for polymers I and II, respectively), and narrow band gaps (1.31 and 1.41 eV, respectively). Photovoltaic devices based on a polymer-II-PC₆₀BM (1: 3, wt/wt) mixture under AM 1.5 irradiation of 100 mV/cm² exhibit a power-conversion efficiency of ～0.29%, a short-circuit current of 1.45 mA/cm², an open-circuit voltage of V _oc = 0.67 V, and a fill factor of 0.30. These results are evidence that thienopyrazine functional groups are attractive as electron-acceptor building blocks in organic electronics.     

含有异噁唑的S-三唑[3,4-b]-1,3,4-噻二嗪、咪唑[2,1-b]-1,3,4-噻二唑和咪唑[2,1-b]-1,3,4-噁二唑衍生物的合成

异噁唑衍生物作为一类重要的生物活性物质,其合成一直受到人们的关注,其中德国HMR公司开发研制的新型抗内风湿性关节炎药来氟米特(Leftunomide)已于1998年在美国率先上市,该药还具有很好的免疫调节作用．7H-均三唑[3,4-b]-1,3,4-噻二嗪、咪唑并[2,1-b]噻唑和咪唑并[2,1-b]-1,3,4-噻二唑衍生物均表现出广谱的生物活性．     

呋喃[2,3-b]喹啉衍生物的合成及其生物活性研究进展

呋喃[2,3-b]喹啉骨架作为目前发现数目最为庞大的一类天然呋喃喹啉结构,因其丰富的结构与良好的生物活性,吸引了大量研究者的关注。近年来,不仅许多新的天然呋喃[2,3-b]喹啉不断从自然界中被发现,而且基于生物活性研究的衍生物制备也得到蓬勃发展。为了充分利用这一宝贵天然资源,为活性天然产物的结构改造提供一定指导与参考,本文对近二十年来呋喃[2,3-b]喹啉衍生物的合成以及相关生物活性研究进行了总结,并展望其前景。     

噻吩并[2,3-b]吡啶类化合物的合成及生物活性

用邻氨基噻吩腈与不同结构的二羰基化合物反应,合成了新的多取代噻吩并吡啶类衍生物4-氨基-5-取代羰基噻吩并[2,3-b]吡啶-6-酮。用元素分析、红外光谱、核磁共振氢谱和质谱等测试技术对所合成化合物的结构进行了表征。初步生物活性测试表明,该类化合物有较好的杀菌活性和一定的除草活性。     

噻吩并[2,3-b]吡啶化合物的合成及应用

噻吩并[2;3-b]吡啶;生物活性;医药;农药;合成     

Mild and efficient Winterfeldt oxidation of 1,2,3,4-tetrahydro-γ-carbolines for the synthesis of dihydropyrrolo[3,2-b]-quinolones and pyrrolo[3,2-b]quinolones

The Winterfeldt oxidation (NaOH, DMF, air, rt) of substituted 1,2,3,4-tetrahydro-γ-carbolines has been developed, which provides a convenient and efficient method for the synthesis of the corresponding dihydropyrrolo[3,2-b]quinolones in moderate to excellent yields (38-94%). The generality and substrate scope of this reaction are explored and a possible mechanism is proposed. The results imply that electron-withdrawing groups on N2 of tetrahydro-γ-carbolines and N5-H are necessary. The synthesis of 5 or 7-substituted pyrrolo[3,2-b]quinolones in near quantitative yields was also achieved through deprotection and aromatization of N1-Boc-dihydropyrrolo[3,2-b]quinolones.     

A useful ring transformation route to novel thiazepino[7,6-b]indoles from monochloro-β-lactam-fused 1,3-thiazino[6,5-b]indoles,analogues of cyclobrassinin

The Staudinger ketene-imine cycloaddition reactions of cyclobrassinin phytoalexin analogues 2-aryl-4,9-dihydro-1,3-thiazino[6,5-b]indoles with chloroacetyl chloride as a ketene source were investigated under different conditions. Both β-lactam ring formation and the N-chloroacetylation of the indole moiety took place. The indole N-chloroacetyl group can be easily removed by treatment in the presence of silica gel in methanol at reflux temperature. The selective β-lactam formation can be also achieved in certain cases under milder Staudinger conditions. The treatment of azeto[2,1-b]thiazino[6,5-b]indole-1-one derivatives with sodium ethoxide in ethanol provided the novel thiazepino[7,6-b]indole ring systems in a one-step ring transformation. The structures of the new ring systems were determined by means of IR and NMR spectroscopy.     

Angular-shaped naphthodifurans, naphtho[1,2-b;5,6-b']- and naphtho[2,1-b;6,5-b']-difuran: are they isoelectronic with chrysene?

Although angular-shaped naphthodifurans, naphtho[1,2-b;5,6-b']- and naphtho[2,1-b;6,5-b']-difuran, are formally isoelectronic with chrysene as their thiophene counterparts, naphtho[1,2-b;5,6-b']- and naphtho[2,1-b;6,5-b']-dithiophene, the HOMO energy level of naphthodifurans is much higher than those of naphthodithiophenes and chrysene. The difference in electronic structure in the ground state can be explained by distinct electronic perturbation from the outermost aromatic rings.