- Direct Access to S-Heterocycles by Scandium(III) Triflate Catalyzed Cyclization of Aromatic Thiols and Diols
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A simple and environmentally friendly method to prepare S-heterocycles by cyclization of aromatic thiols and diols with H2O as a byproduct is described. The Sc(OTf)3-catalyzed dehydrative cyclizations of aromatic thiols and diols provided the corresponding thiopyran and thiophene derivatives. Control experiments were also performed to obtain insights into the reaction pathway.
- Minakawa, Maki,Minami, Keisuke,Sato, Yuya
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p. 1869 - 1873
(2021/07/31)
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- Insight into Regioselective Control in Aerobic Oxidative C-H/C-H Coupling for C3-Arylation of Benzothiophenes: Toward Structurally Nontraditional OLED Materials
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The installation of (benzo)thiophene-containing biaryls via coupling reactions has become a staple in designing photoelectric materials. Undeniably, C-H/C-H cross-coupling reactions between two (hetero)aromatics would be a shortcut toward these structural fragments. While more reliable cross-coupling technologies are well-established to provide C2-arylated (benzo)thiophenes, efficient methods that arylate the C3-position remain underdeveloped. Herein we provide insight into the factors that determine regioselectivity switching for these cross-coupling reactions. X-ray crystallographic analysis gives solid evidence for the key roles of triflate in regioselective dearomatization and acetate in base-assisted anti-β-deprotonated rearomatization. The first isolation and X-ray characterization of a medium-sized dearomatized cyclometalated adduct involving both substrates provide extra insight into aerobic oxidative Ar-H/Ar-H cross-coupling reactions. The mechanistic breakthrough incubates the first example, enabling C-H/C-H-type C3-arylation of benzothiophenes. Finally, this chemistry is used to design blue-emitting thermally activated delayed fluorescence (TADF) materials with a helicene conformation that exhibit a high maximum external quantum efficiency of 25.4% in OLED.
- Bin, Zhengyang,Liao, Xingrong,Liu, Jiahui,Shen, Boming,Shi, Yang,Yan, Lipeng,Yang, Feng,Yang, Ge,Yang, Yudong,You, Jingsong,Yu, Peiyuan
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- Pd-Catalyzed C—S Cyclization via C—H Functionalization Strategy: Access to Sulfur-containing Benzoheterocyclics
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A C—H sulfurated cyclization protocol starting from thioacetates is developed for straightforward construction of sulfur-containing benzoheterocyclics. The diversiform functional dihydrobenzothiophenes and thiochromans were comprehensively achieved through the Pd-catalyzed carbon- sulfur cyclization. Mechanistic studies indicated that C—H bond cleavage was involved in the rate-determining step. [1]Benzothieno-[3,2-b]- [1]benzothiophene (BTBT) and benzo[b]thieno[2,3-d]thiophene (BTT) were efficiently established as the well-known organic field-effect transistor (OFET) material molecules through this methodology.
- Chen, Shihao,Wang, Ming,Jiang, Xuefeng
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supporting information
p. 921 - 924
(2018/09/22)
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- Further insight into the photochemical behavior of 3-aryl-N-(arylsulfonyl)propiolamides: tunable synthetic route to phenanthrenes
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Reported herein is further insight into the photochemical behaviour of 3-aryl-N-(arylsulfonyl)-propiolamides, which provides a straightforward way to access meaningful phenanthrenes. Mechanistic investigation indicated that aryl migration, C-C coupling, 1,3-hydrogen shift, desulfonylation and elimination were involved in the process. Moreover, this protocol allowed for scale-up using a flow reactor.
- Chen, Ming,Zhao, Xinxin,Yang, Chao,Wang, Yanpei,Xia, Wujiong
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p. 12022 - 12026
(2017/03/01)
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- Air-Driven Potassium Iodide-Mediated Oxidative Photocyclization of Stilbene Derivatives
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A new method has been developed for the potassium iodide-mediated oxidative photocyclization of stilbene derivatives. Compared with conventional iodine-mediated oxidative photocyclization reactions, this new method requires shorter reaction times and affords cyclized products in yields of 45-97%. This reaction proceeds with a catalytic amount of potassium iodide and works in an air-driven manner without the addition of an external scavenger. The radical-mediated oxidative photocyclization of stilbene derivatives using TEMPO was also investigated.
- Matsushima, Tomoya,Kobayashi, Sayaka,Watanabe, Soichiro
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p. 7799 - 7806
(2016/09/09)
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- Base-Promoted/Gold-Catalyzed Intramolecular Highly Selective and Controllable Detosylative Cyclization
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A highly selective, controllable and synthetically useful base-promoted intramolecular detosylative cyclization of bis-N-tosylhydrazones has been achieved, affording N-containing heterocycles and cyclic olefins under transition-metal-free or gold-catalyzed procedures, respectively. Moreover, an effective and practical metal-free or gold-catalyzed approach to synthesize polycyclic aromatic compounds is also reported. Basic cyclizations: A highly selective, controllable, and synthetically useful base-promoted intramolecular detosylative cyclization of bis-N-tosylhydrazones affords N-containing heterocycles and cyclic olefins under transition-metal-free or gold-catalyzed procedures, respectively. Moreover, an effective and practical metal-free or gold-catalyzed approach to synthesize polycyclic aromatic compounds is also reported.
- Zhu, Chenghao,Qiu, Lin,Xu, Guangyang,Li, Jian,Sun, Jiangtao
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supporting information
p. 12871 - 12875
(2015/09/07)
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- Bismuth-catalyzed synthesis of polycyclic aromatic hydrocarbons (PAHs) with a phenanthrene backbone via cyclization and aromatization of 2-(2-arylphenyl)vinyl ethers
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The reaction of 2-(2-arylphenyl)vinyl ethers in the presence of a catalytic amount of bismuth(III) triflate gave substituted phenanthrenes in excellent yields under mild reaction conditions. The reaction was also applied to the construction of other polycyclic aromatic hydrocarbons (PAHs), such as chrysene, helicene, and pyrene having a phenanthrene backbone, via regioselective cyclization. This method has the advantages of easy availability of the cyclization precursors, operational simplicity, and high reaction efficiency.
- Murai, Masahito,Hosokawa, Naoki,Roy, David,Takai, Kazuhiko
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supporting information
p. 4134 - 4137
(2014/09/30)
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- Rhodium(II)-catalyzed cyclization of bis(N-tosylhydrazone)s: An efficient approach towards polycyclic aromatic compounds
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Ahead of the PAC: Polycyclic aromatic compounds (PACs) can be easily accessed by the combination of Suzuki-Miyaura cross-coupling and a [Rh 2(OAc)4]-catalyzed carbene reaction using easily available bis(N-tosylhydrazone)s as intermediates (see scheme; Ts=4-toluenesulfonyl). Copyright
- Xia, Ying,Liu, Zhenxing,Xiao, Qing,Qu, Peiyuan,Ge, Rui,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 5714 - 5717
(2012/07/28)
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- A facile two-step synthesis of thiophene end-capped aromatic systems
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Thiophene end-capped aromatic analogues, that is, naphthothiophenes, naphthodithiophenes, pyrenothiophene, and benzotrithiophene, can be prepared from commercially available hydroxyarenes in two steps, including (1) a consecutive acid-mediated nucleophilic aromatic substitution of hydroxyarenes with 2-mercaptoethanol, followed by cyclization to form an arene-fused dihydrothiophene, and (2) oxidation of the dihydrothiophene unit to thiophene.
- Rungtaweevoranit, Bunyarat,Butsuri, Akkarapol,Wongma, Krittaphat,Sadorn, Karoon,Neranon, Kitjanit,Nerungsi, Chakkrapan,Thongpanchang, Tienthong
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p. 1816 - 1818
(2012/05/05)
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- One-pot synthesis using the supported reagent system Na2CO 3/SiO2-PPA/SiO2: Synthesis of Benzo[b]thiophenes and naphthothiophenes
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A simple and efficient method has been developed for the synthesis of benzo[b]thiophenes and naphtho[2,l-6]thiophenes from arenethiols and α-halo ketones using Na2CO3/SiO2-PPA/ SiO2. Reaction of a-halo ketones with arenethiols is promoted by Na2CO3/SiO2 to afford α-sulfanyl ketones, which cyclize in the presence of PPA/SiO2 to give the corresponding thiophene-fused arenes in one-pot. The reaction using α-bromo acetals instead of α-halo ketones also gave the corresponding naphtho[2,l-b] thiophenes via a three-step reaction in one-pot. Thieme Stuttgart.
- Aoyama, Tadashi,Orito, Mami,Takido, Toshio,Kodomari, Mitsuo
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body text
p. 2089 - 2099
(2009/04/03)
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- Flash vacuum pyrolysis of 3-aroylcinnolines: Interesting routes toward polynuclear aromatic compounds
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Flash vacuum pyrolysis of 3-aroylcinnolines 3 at 900°C and 0.02 Torr yielded phenanthrene and arylacetylene derivatives as the major products beside anthracene and diarylacetylene derivatives as minor products. Also, FVP of 3-(2-thienoyl)-cinnoline gave three isomeric naphthothiophenes, phenyl-2-thienylacetylene and phenylacetylene. On the other hand, 3-(2-furoyl)-cinoline gave dibenzofuran as a major product besides naphtho[1,2-b]furan and phenylacetylene.
- Ibrahim, Yehia A,Al-Awadi, Nouria A,Kaul, Kamini
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p. 7377 - 7381
(2007/10/03)
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- Application of flash vacuum pyrolysis to the synthesis of sulfur- containing heteroaromatic systems
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The FVP method of ethynyl and chlorovinyl materials is applied to the ready formation of sulfur-containing fused heteroaromatic systems. The pyrolysis of the chlorovinyl materials is assumed to involve a mechanism different from that of the ethynyl materials.
- Imamura, Koichi,Hirayama, Daigo,Yoshimura, Hitoshi,Takimiya, Kazuo,Yoshio, Aso,Otsubo, Tetsuo
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p. 2789 - 2792
(2007/10/03)
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- Regiospecific Functionalization of Dimetalated (1-Naphthyl)acetylene. Efficient Synthetic Procedures for Naphthochalcophenes
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Treatment of (1-naphthyl)acetylene (1) with two mol equivalents of the BuLi-t-BuOK reagent in tetrahydrofuran/hexane, followed by successive addition of anhydrous lithium bromide, sulfur, selenium, or tellurium and t-butylalcohol gives naphthothiophene, -selenophene and -tellurophene in good yields.Reactions of dimetalated 1 with iodine or dimethyldisulfide afforded 2-iodo-, and 2-thiomethyl(1-ethynyl)naphthalene.
- Hanecamp, Jaap C.,Klusener, Peter A. A.,Brandsma, Lambert
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p. 2691 - 2702
(2007/10/02)
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- SYNTHESIS AND CHEMICAL TRANSFORMATIONS OF ISOMERIC NAPHTHOTHIOPHENES
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A new method for the preparation of naphtho- and naphthothiophene structures by arylation of acrylic acid with α- and β-iodonaphthalene and subsequent oxidation of the resulting trans-naphthylacrylic acids with thionyl chloride in the presence of triethylbenzylammonium chloride is proposed.
- Sidorenko, T. N.,Terent'eva, G. A.,Andrienko, O. S.,Savinykh, Yu. V.,Aksenov, V. S.
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p. 156 - 160
(2007/10/02)
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- The Synthesis of Dinaphthothiophenes
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The synthesis of dinaphthothiophene (6), dinaphthothiophene (15), dinaphthothiophene (20), dinaphthothiophene (26), dinaphthothiophene (37) and dinaphthothiophene (45) has been accomplished.
- Tedjamulia, Marvin L.,Tominaga, Yoshinori,Castle, Raymond N.,Lee, Milton L.
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p. 1143 - 1148
(2007/10/02)
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