18761-36-9Relevant academic research and scientific papers
Transition Metal-Free Synthesis of Halobenzo[b]furans from O-Aryl Carbamates via o-Lithiation Reactions
Feberero, Claudia,Renedo, Lorena,Sanz, Roberto,Sedano, Carlos,Suárez-Pantiga, Samuel,Virumbrales, Cintia
, (2022/01/24)
A straightforward and transition metal-free one-pot protocol to synthesize halobenzo[b]furans has been developed employing simple and easily available starting materials such as O-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involved was key to achieving a successful one-pot procedure. Initially, a directed ortho-lithiation process, which uses the carbamate as the directed metalation group, was crucial in providing access to O-2-alkynylaryl N,N-diethyl carbamates by a direct alkynylation of the o-lithiated carbamate, with arylsulfonylalkynes as electrophilic reagents. Cyclization of the generated o-alkynylaryl carbamates was successfully accomplished through a strategy involving in situ carbamate alkaline hydrolysis under conventional heating or microwave irradiation, coupled with a subsequent heterocyclization step delivering the desired benzo[b]furans. A wide variety of new halobenzo[b]furans has been synthesized and their utility has been demonstrated by their further transformation.
Highly Efficient Synthesis of 2-Substituted Benzo[ b ]furan Derivatives from the Cross-Coupling Reactions of 2-Halobenzo[ b ]furans with Organoalane Reagents
Wen, Chang,Wu, Chuan,Luo, Ruiqiang,Li, Qinghan,Chen, Feng
supporting information, p. 3847 - 3861 (2021/07/02)
A highly efficient and simple route for the synthesis of 2-substituted benzo[ b ]furans has been developed by palladium-catalyzed cross-coupling reaction of 2-halobenzo[ b ]furans with aryl, alkynyl, and alkylaluminum reagents. Various 2-aryl-, 2-alkynyl-, and 2-alkyl-substituted benzo[ b ]furan derivatives can be obtained in 23-97% isolated yields using 2-3 mol% PdCl 2/4-6 mol% XantPhos as the catalyst under mild reaction conditions. The aryls bearing electron-donating or electron-withdrawing groups in 2-halobenzo[ b ]furans gave products in 40-97% isolated yields. In addition, aluminum reagents containing thienyl, furanyl, trimethylsilanyl, and benzyl groups worked efficiently with 2-halobenzo[ b ]furans as well, and three bioactive molecules with 2-substituted benzo[ b ]furan skeleton were synthesized. Furthermore, the broad substrates scope and the typical maintenance of vigorous efficiency on gram scale make this protocol a potentially practical method to synthesize 2-substituted benzo[ b ]furan derivatives. On the basis of the experimental results, a possible catalytic cycle has been proposed.
Catalyst-Free Synthesis of Benzofuran Derivatives from Cascade Reactions between Nitroepoxides and Salicylaldehydes
Ranjbari, Mohammad A.,Tavakol, Hossein
, p. 4756 - 4762 (2021/04/02)
Different benzofuran derivatives are synthesized via a catalyst-free reaction between nitroepoxides and salicylaldehydes. In the employed methodology, K2CO3 and DMF have been used at 110 °C, and the reactions were completed after 12 h in 33-84% yields. Th
Acid-promoted selective synthesis of trifluoromethylselenolated benzofurans with Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate
Liu, Juyan,Tian, Miaomiao,Li, Ankun,Ji, Liangshuo,Qiu, Di,Zhao, Xia
supporting information, (2021/02/01)
A Br?nsted acid-promoted trifluoromethylselenolation of benzofurans was disclosed by using Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate as a stable and easily prepared electrophilic trifluoromethylselenolating reagent. A wide range of SeCF3-substituted benzofuran derivatives were obtained in moderate to good yields with excellent regioselectivity. The tandem cyclization/trifluoromethylselenolation procedure of 1-methoxy-2-(arylethynyl)benzenes were also realized by engaging FeCl3 as the catalyst.
Synthesis of benzofurans from terminal alkynes and iodophenols catalyzed by recyclable palladium nanoparticles supported on N,O-dual doped hierarchical porous carbon under copper- and ligand-free conditions
Ji, Guijie,Duan, Yanan,Zhang, Shaochun,Yang, Yong
, p. 101 - 108 (2018/05/05)
We herein report that a stable and recyclable heterogeneous catalyst, consisting of Pd nanoparticles supported on N,O-dual doped hierarchical porous carbon derived from naturally available and renewable biomass-bamboo shoots, which allows for highly efficient one-pot tandem reaction of o-iodophenols with terminal alkynes to synthesize biologically active 2-benzofuran derivatives under copper- and ligand-free conditions. The catalyst performed superior catalytic performance compared with the analogous Pd/C and supported on other metal oxides under otherwise identical conditions. A broad set of aryl and alkyl terminal alkynes can be effectively coupled /cyclized with various o-iodophenols to afford their corresponding 2-benzofurans in good to high yields with good tolerance of multiple functional groups. Moreover, the catalyst showed good stability and could be reused several times without significant loss of activity.
CuI catalyzed domino coupling–cyclization of 2-iodo-phenols and 1-alkynes to the synthesis of 2-substituted benzo[b]furans/furo-pyridines
Chen, Ze-Pin,Zhou, Yi,Shui, Meng-Zhu,Liu, Feng
supporting information, p. 133 - 136 (2018/12/11)
CuI/proline-catalyzed coupling reaction of 2-iodo-phenols with terminal alkynes and the following cyclization process is carried out successively in DMSO at 80 °C. Under this tandem process, 2-substituted benzo[b]furans/furo-pyridines were synthesized in good to excellent yields with a great diversity.
Method for synthesizing benzofuran derivatives by copper-free ligand-free palladium catalyst
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Paragraph 0007; 0094-0101, (2019/11/13)
The invention relates to a synthesis method of benzofuran derivatives, in particular to a method for synthesizing the benzofuran derivatives by a copper-free ligand-free palladium catalyst. In the presence of K3PO4 solid and a DMF solvent, a compound 1 an
Transition-metal-free base catalyzed intramolecular cyclization of 2-ynylphenols for efficient and facile synthesis of 2-substituted benzo[b]furans
Liu, Yong,Lu, Tao,Tang, Wei-Fang,Gao, Jian
, p. 28637 - 28641 (2018/08/29)
A transition-metal-free base catalyzed intramolecular cyclization of 2-ynylphenols was developed for the facile synthesis of 2-substituted benzo[b]furans. Various 2-aryl and 2-alkyl substituted benzo[b]furans can be obtained with good to excellent yields
Arylation synthesis method for novel five-membered aromatic heterocycle and aromatic-ring five-membered aromatic heterocycle
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Paragraph 0112-0115; 0156-0159, (2018/07/07)
The invention belongs to the technical field of organic synthesis and in particular relates to an arylation synthesis method for a five-membered aromatic heterocycle or an aromatic-ring five-memberedaromatic heterocycle under the participation of an arylhydrazine derivative serving as a novel arylation reagent. The method comprises the steps: adding a raw material and aroyl hydrazine into a reactor, and carrying out a reaction at 60-100 DEG C for 8-24h under the condition that an oxidant and a transition metal catalyst are added; after the reaction is ended, carrying out suction filtration, extracting a filtrate by using ethyl acetate, carrying out drying to obtain a crude product of a target compound, and carrying out column chromatography on silica gel to obtain a pure product of the target compound. The arylation synthesis method for the five-membered aromatic heterocycle or the aromatic-ring five-membered aromatic heterocycle is scientific and reasonable and has the advantages such as simplicity and convenience in operation, relatively high yield and simplicity in amplification and purification.
Method for synthesizing benzofuranol derivative by nickel-catalysis of phenethynyl phenol under microwave irradiation
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Paragraph 0025; 0031, (2018/09/11)
The invention discloses a method for synthesizing a benzofuranol derivative by nickel-catalysis of phenethynyl phenol under microwave irradiation; a catalytic amount of catalyst nickel chloride, ligand 1,10-phenanthroline(1,10-Phen), auxiliary catalyst po
