3782-00-1Relevant articles and documents
Rhodium-Catalyzed Intermolecular Cyclopropanation of Benzofurans, Indoles, and Alkenes via Cyclopropene Ring Opening
Jeyaseelan, Rubaishan,Lautens, Mark,Ross, Rachel J.
supporting information, (2020/06/29)
The generation of metal carbenoids via ring opening of cyclopropenes by transition metals offers a simple entry into highly reactive intermediates. Herein, we describe a diastereoselective intermolecular rhodium-catalyzed cyclopropanation of heterocycles and alkenes using cyclopropenes as carbene precursors with a low loading of a commercially available rhodium catalyst. The reported method is scalable and could be performed with catalyst loadings as low as 0.2 mol %, with no impact to the reaction yield or selectivity.
Method for synthesizing benzofuran derivative by taking alpha-phenoxy-ketone as raw material
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Paragraph 0025; 0026; 0027; 0028; 0073; 0074; 0075; 0076, (2019/04/26)
The invention discloses a method for synthesizing a benzofuran derivative by taking alpha-phenoxy-ketone as a raw material. Under shielding of inert gas, the alpha-phenoxy-ketone is dissolved in dry dichloromethane, then a mixed solution of TiCl4 and dichloromethane is dropwise added slowly, and after the indoor temperature reaction, the benzofuran derivative after separation and purification is obtained. The method for synthesizing the benzofuran derivative has the advantages that raw materials are easy to obtain, the cost is low, and reaction conditions are mild; operation is simple and easyto control, there are fewer side reactions, and the after-processing is simple; the yield of the derivative is higher, the production cost is greatly reduced, better economic benefits are achieved, and the method is suitable for industrial production.
Titanium tetrachloride promoted cyclodehydration of aryloxyketones: Facile synthesis of benzofurans and naphthofurans with high regioselectivity
Zhang, Qiu,Luo, Juan,Wang, Bingqiao,Xiao, Xiaoqin,Gan, Zongjie,Tang, Qiang
supporting information, p. 1337 - 1340 (2019/04/16)
An efficient and facile method for the synthesis of a broad series of benzofurans and naphthofurans is described. The direct intramolecular cyclodehydration of aryloxyketones in the presence of titanium tetrachloride affords the corresponding benzofurans and naphthofurans with good regioselectivity and yields.
In order to phenol and α - halo as raw material synthetic benzofuran derivatives (by machine translation)
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Paragraph 0060; 0061; 0062; 0063, (2019/04/14)
The present invention to provide a phenol and α - halo as raw materials, the role of titanium tetrachloride in the reaction of the next step high-efficient method for preparing benzofuran derivative, namely under protection of inert gas, adding phenol to and [...], then heating and stirring to reflux then adding titanium tetrachloride, finally dropping into the α - halo and [...] mixed solution, after the reaction is completed after the separation and purification to obtain the benzofuran derivatives. The synthesizing method of the invention, raw materials are easy, low cost, mild reaction conditions, the operation is simple and easy to control, less side reaction, after treatment is simple, and the product yield is high, production cost is greatly reduced, with better economic benefits, is suitable for the industrial large-scale production. (by machine translation)
One-step regioselective synthesis of benzofurans from phenols and α-Haloketones
Wang, Bingqiao,Zhang, Qiu,Luo, Juan,Gan, Zongjie,Jiang, Wengao,Tang, Qiang
, (2019/06/21)
Reported here is the direct synthesis of naphthofurans and benzofurans from readily available phenols and α-haloketones promoted by titanium tetrachloride which combines Friedel-Crafts-like alkylation and intramolecular cyclodehydration into one step. This simple protocol allows for the formation of a variety of high value naphthofurans and benzofurans within which a series of cyclic and acyclic groups are readily incorporated. This process demonstrates the advantages of high levels of regioselectivity, broad substrate scope, and moderate to excellent yields.
Pd-catalyzed intramolecular Heck reaction for the synthesis of 2-methylbenzofurans
Zhou,Shi, Yuxing,Zhu, Xueyan,Zhang, Peng
supporting information, p. 2005 - 2008 (2019/07/03)
A new strategy for the synthesis of 2-Methylbenzofurans via the intramolecular Heck reaction has been developed. This efficient palladium-catalyzed system showed good catalytic activity. Various substituted 2-methylbenzofurans could be afforded in good to excellent yields.
Direct Synthesis of 2-Methylbenzofurans from Calcium Carbide and Salicylaldehyde p -Tosylhydrazones
Fu, Rugang,Li, Zheng
supporting information, p. 2342 - 2345 (2018/04/30)
A new methodology for the construction of methyl-substituted benzofuran rings from the reactions of calcium carbide with salicylaldehyde p-tosylhydrazones/2-hydroxyacetophenone p-tosylhydrazones is described. Various 2-methylbenzofurans and 2,3-dimethylbenzofurans could be obtained in satisfactory yield by using a cuprous chloride catalyst. The advantages of this protocol include the use of a readily available and easy-to-handle acetylene source and simple workup procedure.
Short communication: Titanium-induced synthesis of benzofurans
Jumbam,Yedwa,Masamba
experimental part, p. 157 - 160 (2012/05/20)
Ketoesters derived from the acylation of o-hydroxyacetophenone with aliphatic as well as aromatic acid chlorides undergo intramolecular cyclization in the presence of low-valent titanium to afford benzofurans in good yields. The reduction of titanium trichloride with dry zinc powder in refluxing THF takes place in the presence of the ketoester which simultaneously cyclizes as the titanium catalyst is formed, rendering the pre-reduction of titanium trichloride in a separate step unnecessary.
Synthesis of benzo[b]furans via CuI-catalyzed ring closure
Chen, Cheng-Yi,Dormer, Peter G.
, p. 6964 - 6967 (2007/10/03)
A wide variety of benzo[6]furans were synthesized efficiently via a CuI-catalyzed ring closure of 2-haloaromatic ketones. The methodology was tolerant to various functional groups, affording benzofurans in 72-99% yields.
Method of purifying phenol
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Page 3, (2008/06/13)
A method of purifying a phenol stream that contains a concentration of a contaminating compound is provided. The phenol stream is treated or purified by contacting the stream, under suitable process conditions, with a treatment catalyst that has a low silica content but comprises alumina and a Group VIA metal.
