233-02-3Relevant articles and documents
Direct Access to S-Heterocycles by Scandium(III) Triflate Catalyzed Cyclization of Aromatic Thiols and Diols
Minakawa, Maki,Minami, Keisuke,Sato, Yuya
, p. 1869 - 1873 (2021/07/31)
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.
Insight into Regioselective Control in Aerobic Oxidative C-H/C-H Coupling for C3-Arylation of Benzothiophenes: Toward Structurally Nontraditional OLED Materials
Bin, Zhengyang,Liao, Xingrong,Liu, Jiahui,Shen, Boming,Shi, Yang,Yan, Lipeng,Yang, Feng,Yang, Ge,Yang, Yudong,You, Jingsong,Yu, Peiyuan
, (2021/12/14)
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.
Pd-Catalyzed C—S Cyclization via C—H Functionalization Strategy: Access to Sulfur-containing Benzoheterocyclics
Chen, Shihao,Wang, Ming,Jiang, Xuefeng
supporting information, p. 921 - 924 (2018/09/22)
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.
Further insight into the photochemical behavior of 3-aryl-N-(arylsulfonyl)propiolamides: tunable synthetic route to phenanthrenes
Chen, Ming,Zhao, Xinxin,Yang, Chao,Wang, Yanpei,Xia, Wujiong
, p. 12022 - 12026 (2017/03/01)
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.
Air-Driven Potassium Iodide-Mediated Oxidative Photocyclization of Stilbene Derivatives
Matsushima, Tomoya,Kobayashi, Sayaka,Watanabe, Soichiro
, p. 7799 - 7806 (2016/09/09)
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.
Base-Promoted/Gold-Catalyzed Intramolecular Highly Selective and Controllable Detosylative Cyclization
Zhu, Chenghao,Qiu, Lin,Xu, Guangyang,Li, Jian,Sun, Jiangtao
supporting information, p. 12871 - 12875 (2015/09/07)
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.
Bismuth-catalyzed synthesis of polycyclic aromatic hydrocarbons (PAHs) with a phenanthrene backbone via cyclization and aromatization of 2-(2-arylphenyl)vinyl ethers
Murai, Masahito,Hosokawa, Naoki,Roy, David,Takai, Kazuhiko
supporting information, p. 4134 - 4137 (2014/09/30)
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.
A facile two-step synthesis of thiophene end-capped aromatic systems
Rungtaweevoranit, Bunyarat,Butsuri, Akkarapol,Wongma, Krittaphat,Sadorn, Karoon,Neranon, Kitjanit,Nerungsi, Chakkrapan,Thongpanchang, Tienthong
, p. 1816 - 1818 (2012/05/05)
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.
Rhodium(II)-catalyzed cyclization of bis(N-tosylhydrazone)s: An efficient approach towards polycyclic aromatic compounds
Xia, Ying,Liu, Zhenxing,Xiao, Qing,Qu, Peiyuan,Ge, Rui,Zhang, Yan,Wang, Jianbo
supporting information; experimental part, p. 5714 - 5717 (2012/07/28)
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
One-pot synthesis using the supported reagent system Na2CO 3/SiO2-PPA/SiO2: Synthesis of Benzo[b]thiophenes and naphthothiophenes
Aoyama, Tadashi,Orito, Mami,Takido, Toshio,Kodomari, Mitsuo
body text, p. 2089 - 2099 (2009/04/03)
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.
