936734-95-1Relevant academic research and scientific papers
Regioselective Direct C2 Arylation of Indole, Benzothiophene and Benzofuran: Utilization of Reusable Pd NPs and NHC-Pd@MNPs Catalyst for C–H Activation Reaction
Hegde, Rajeev V.,Ong, Tiow-Gan,Ambre, Ram,Jadhav, Arvind H.,Patil, Siddappa A.,Dateer, Ramesh B.
, p. 1397 - 1405 (2020/10/02)
Abstract: A regioselective C2 arylation of indoles, benzothiophene and benzofuran without directing group has been accomplished using economically cheap Pd NPs and NHC-Pd@MNPs catalyst. The reusable catalyst is efficiently employed to access C2 arylated heterocycles in good to excellent yield. The reusability of the catalyst is studied up to five cycles and a gram-scale synthesis has been achieved. The reaction mechanism is well supported by control experiments and literature precedents. Grapic Abstract: [Figure not available: see fulltext.]
Synthesis of 2-substituted benzo[: B] thiophenes via gold(i)-NHC-catalyzed cyclization of 2-alkynyl thioanisoles
Dillon, Christopher C.,Keophimphone, Bagieng,Sanchez, Melissa,Kaur, Parveen,Muchalski, Hubert
supporting information, p. 9279 - 9284 (2019/01/03)
Benzo[b]thiophene heterocycles are important components of many important small molecule pharmaceuticals and drug candidates as well as organic semiconducting materials. Many methods have been developed for the construction of a benzo[b]thiophene core via cyclization reaction of alkynes. Although few catalytic reactions were disclosed, most methods rely on stoichiometric activation of alkynes. Here we report an efficient method for the synthesis of 2-substituted benzo[b]thiophenes from 2-alkynyl thioanisoles catalyzed by a gold(i)-IPr hydroxide that is applicable to a wide range of substrates with diverse electronic and steric properties. Additionally, we demonstrate experimentally that the acid additive and its conjugate base are essential to catalyst turnover.
Ag(I)-C-H Activation Enables Near-Room-Temperature Direct α-Arylation of Benzo[ b]thiophenes
Colletto, Chiara,Panigrahi, Adyasha,Fernández-Casado, Jaime,Larrosa, Igor
supporting information, p. 9638 - 9643 (2018/07/21)
The first example of near-room-temperature α-arylation of benzo[b]thiophenes is reported. The discovery rests on the observation of a switch in α-/β-regioselectivity at different loadings of Pd2(dba)3·CHCl3 in the coupling between benzo[b]thiophene and 4-iodotoluene. We show that this unprecedented regioselectivity switch is driven by a Ag(I)-mediated C-H activation at the α-C-H position, which becomes the dominant mode of reactivity at low concentrations of Pd. Competition experiments, kinetic studies, KIE, and D/H scrambling experiments have been carried out supporting this mechanism.
Method for synthesizing benzothiophene derivative by catalysis of dihalogenated aromatics by copper
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Paragraph 0026; 0059, (2018/08/28)
The invention discloses a method for synthesizing a benzothiophene derivative by catalysis of dihalogenated aromatics by copper. According to the invention, a catalyst cuprous iodide with a catalysisamount, a ligand 8-hydroxyquinoline, an auxiliary catalyst cesium carbonate and 1-bromine-2-iodobenzene or its derivative, sulfur powder, and phenylacetylene or its derivative are added in a flask andsubjected to a reaction in pure water at certain temperature, after a certain time, vacuum concentration is carried out, and a product is purified through column chromatography. The method has the advantages of novel raw material and simple operation, and can be used for efficiently preparing the benzothiophene derivative. Compared with the prior art, the method has the advantages of mild reaction condition, simple operation, high yield, safety, low cost, and environmental protection.
Method for synthesizing benzothiophene derivatives from dihaloarene under microwave irradiation under catalysis of copper
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Paragraph 0030; 0073, (2018/09/08)
The invention discloses a method for synthesizing benzothiophene derivatives from dihaloarene under microwave irradiation under the catalysis of copper. The method comprises the following steps: adding a catalytic amount of a catalyst copper chloride, a ligand 1,10-phenanthroline (1,10-Phen), a cocatalyst potassium hydroxide, 1-bromo-2-iodobenzene and its derivatives, KSCN (potassium thiocyanate),phenylacetylene and pure water, performing a reaction in a microwave reactor at a certain temperature under a certain power for a certain time, performing reduced pressure concentrating, and performing column chromatography purification on the obtained product. The method disclosed in the invention is a method having novel raw materials, being simple to operate and used for efficiently preparingthe benzothiophene derivatives. Compared with the prior art, the method has an obvious faster reaction speed than convectional heating, and has the advantages of mild reaction conditions, simplicity in operation, high yield, safety, low cost and environmental protection.
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 (2016/04/26)
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.
General method for functionalized polyaryl synthesis via aryne intermediates
Truong, Thanh,Mesgar, Milad,Le, Ky Khac Anh,Daugulis, Olafs
, p. 8568 - 8576 (2014/07/07)
A method for base-promoted arylation of arenes and heterocycles by aryl halides and aryl triflates is described. Additionally, in situ electrophilic trapping of ArLi intermediates generated in the reaction of benzyne with deprotonated arenes or heterocycles has been developed, providing rapid and easy access to a wide range of highly functionalized polyaryls. Base-promoted arylation methodology complements transition-metal-catalyzed direct arylation and allows access to structures that are not easily accessible via other direct arylation methods. The reactions are highly functional-group tolerant, with alkene, ether, dimethylamino, trifluoromethyl, ester, cyano, halide, hydroxyl, and silyl functionalities compatible with reaction conditions.
Selective palladium-catalysed ipso arylation of α,α- disubstituted benzo[b]thien-2-ylmethanols with aryl bromides using PCy 3 as ligand
Biro, A. Beatrix,Kotschy, Andras
, p. 1364 - 1368 (2008/09/18)
α,α-Diphenylbenzo[b]thien-2-ylmethanol was treated with a series of aryl bromides in the presence of palladium(II) acetate and tricyclohexylphosphane to give the appropriate 2-aryl-benzo[b]thiophenes in good to excellent yield with concomitant formation o
