10371-50-3Relevant articles and documents
Potassium Hydroxide/Dimethyl Sulfoxide Superbase-Promoted Transition Metal-Free Synthesis of 2-Substituted Benzothiophenes under Visible Light
Gao, Li,Chang, Bin,Qiu, Wenzhao,Wang, Lele,Fu, Xianzhi,Yuan, Rusheng
, p. 1202 - 1207 (2016)
A potassium hydroxide/dimethyl sulfoxide (KOH/DMSO) superbase-promoted method for the synthesis of 2-substituted benzothiophenes has been developed via photoinduced intermolecular annulation of 2-halothioanisoles with terminal alkynes at ambient temperature. The present protocol uses commercially available 2-halothioanisoles as substrates and visible light as energy force, which offers a wide range of benzothiophenes regioselectively in moderate to good yields. Such a facile and effective transformation will provide an environment-friendly approach to the synthesis of benzothiophene derivatives.
Phenyl migration to thiophene ring in photolysis of 1-phenylbenzo[b]thiophenium salts
Kitamura, Tsugio,Morizane, Kunihiko,Taniguchi, Hiroshi,Fujiwara, Yuzo
, p. 5157 - 5160 (1997)
Photolysis of 1-phenylbenzo[b]thiophenium salts was conducted by use of a Pyrex-filtered high pressure Hg lamp. The major products in most cases were the phenyl-migrated ones, i.e., 2-phenylbenzo[b]thiophenes and 3-phenylbenzo[b]thiophenes, together with the dephenylated benzo[b]thiophenes. This photochemical behavior is quite different from the thermal ones that provide the ring-opened olefins. The selective phenyl migration to the thiophene ring and the absence of the ionic products are characteristic of benzothiophenium systems.
Nickel-catalyzed and Li-mediated regiospecific C-H arylation of benzothiophenes
Canivet, Jér?me,Grousset, Léonie,Hisler, Ga?lle,Mohr, Yorck,Quadrelli, Elsje Alessandra,Roux, Yoann,Wisser, Florian M.
, p. 3155 - 3161 (2020/06/19)
A nickel-based catalytic system for the regiospecific C2-H arylation of benzothiophene has been established. NiCl2(bpy) is used as a catalyst in combination with LiHMDS as a base in dioxane. The catalytic system is applicable to a variety of functionalized benzothiophenes, as well as other heteroarenes including thiophene, benzodithiophene, benzofuran and selenophene in combination with iodo aryl electrophiles. The role of LiHMDS as a uniquely potent base and a postulated mechanism are discussed. The applicability of this system is finally demonstrated for the synthesis of an intermediate of an active pharmaceutical ingredient.
Integration of a Four-Step Reaction into One-Pot under the Coexistence of Silica-Gel-Supported Acid and Base Reagents: Synthesis of Benzo- and Naphthothiophenes Using NaHSO 4 /SiO 2 and Na 2 CO 3 /SiO 2
Aoyama, Tadashi,Hayakawa, Mamiko,Kosuge, Masayuki,Nakaoka, Kyohei,Ouchi, Akihiko
supporting information, p. 2572 - 2578 (2019/06/08)
A four-step synthesis of benzo- and naphthothiophenes that have biological importance and application in material science was integrated into a one-pot reaction by using silica gel-supported acid and base reagents, NaHSO 4 /SiO 2 and Na 2 CO 3 /SiO 2. The supported reagents provided acid and base environments on the surface of the supports without neutralization and worked separately in the same medium. The four-step reaction comprises (i) deacetylation of 3-halo-2,4-pentanediones to α-halo ketones, (ii) deacetylation of S -aryl thioacetates to arenethiols, (iii) coupling of α-halo ketones and arenethiols to give α-sulfanyl ketones, and (iv) cyclization of sulfanyl ketones to benzo- and naphthothiophenes. The steps (i) and (iii) proceeded by Na 2 CO 3 /SiO 2, and (ii) and (iv) by NaHSO 4 /SiO 2. The four-step reaction proceeded efficiently by introduction of starting materials and reagents in a single reaction vessel. The starting materials were very easy to handle and unpleasant smell of aryl thiols that were used in conventional methods could be avoided. Novel thirty-nine benzo- and naphthothiophenes were synthesized by this method in excellent to fair yields.
