912762-95-9Relevant academic research and scientific papers
Direct Arylations of Heteroarenes with Benzenesulfonyl Chlorides Using Pd/C Catalyst
Mao, Shuxin,Shi, Xinzhe,Soulé, Jean-Fran?ois,Doucet, Henri
, p. 91 - 97 (2019/12/30)
The reactivity of heteroaromatics in direct arylation with benzenesulfonyl chlorides using 10 % Pd/C as catalyst was explored. With (benzo)thiophenes, (benzo)furans, pyrroles and selenophenes, high yields in arylated heteroarenes were obtained. These arylations were performed using only 5 mol-% Pd/C and Li2CO3 as inexpensive base. The regioselectivities are similar to those observed with homogeneous palladium catalysts. Better yields were obtained with electron-deficient benzenesulfonyl chlorides than with the electron-rich ones. Notably, useful substituents such as bromo or iodo on the benzenesulfonyl chloride were tolerated, as no cleavage of the C–Br or C–I bonds was observed under these conditions. The use of Pd/C presents several advantages compared to the previously employed homogeneous palladium catalysts, as it can be easily removed by filtration at the end of the reaction. The major side-products of the reaction are HBr associated to Li2CO3. Therefore, this new protocol affords a very attractive synthetic scheme in terms of cost, simplicity and low environmental impact for the access to arylated heteroaromatics.
A case of chain propagation: α-aminoalkyl radicals as initiators for aryl radical chemistry
Constantin, Timothée,Juliá, Fabio,Leonori, Daniele,Sheikh, Nadeem S.
, p. 12822 - 12828 (2020/12/29)
The generation of aryl radicals from the corresponding halides by redox chemistry is generally considered a difficult task due to their highly negative reduction potentials. Here we demonstrate that α-aminoalkyl radicals can be used as both initiators and chain-carriers for the radical coupling of aryl halides with pyrrole derivatives, a transformation often employed to evaluate new highly reducing photocatalysts. This mode of reactivity obviates for the use of strong reducing species and was also competent in the formation of sp2 C-P bonds. Mechanistic studies have delineated some of the key features operating that trigger aryl radical generation and also propagate the chain process.
Visible-light photocatalyzed synthesis of 2-aryl N-methylpyrroles, furans and thiophenes utilizing arylsulfonyl chlorides as a coupling partner
Natarajan, Palani,Bala, Anu,Mehta,Bhasin
, p. 2521 - 2526 (2016/04/26)
Visible-light (Blue LED lamp: hν=425±15 nm) photocatalyzed cross-coupling reactions of arylsulfonyl chloride with N-methylpyrrole, furan, thiophene and their derivatives have been achieved in moderate to good yields at room temperature. A plausible mechan
Chromoselective Photocatalysis: Controlled Bond Activation through Light-Color Regulation of Redox Potentials
Ghosh, Indrajit,K?nig, Burkhard
supporting information, p. 7676 - 7679 (2016/07/07)
Catalysts that can be regulated in terms of activity and selectivity by external stimuli may allow the efficient multistep synthesis of complex molecules and pharmaceuticals. Herein, we report the light-color regulation of the redox potential of a photocatalyst to control the activation of chemical bonds. Light-color control of the redox power of a photocatalyst introduces a new selectivity parameter to photoredox catalysis: Instead of changing the catalyst or ligand, alteration of the color of the visible-light irradiation adjusts the selectivity in catalytic transformations. By using this principle, the selective activation of aryl–halide bonds for C?H arylation and the sequential conversion of functional groups with different reduction potentials is possible by simply applying different colors of light for excitation of the photocatalyst.
Pd-Catalysed Direct Arylation of Heteroaromatics Using (Poly)halobenzenesulfonyl Chlorides as Coupling Partners: One Step Access to (Poly)halo-Substituted Bi(hetero)aryls
Skhiri, Aymen,Beladhria, Anissa,Yuan, Kedong,Soulé, Jean-Francois,Ben Salem, Ridha,Doucet, Henri
, p. 4428 - 4436 (2015/07/27)
The reactivity of (poly)halo-substituted benzenesulfonyl chlorides for Pd-catalysed desulfitative arylation was investigated. 2-, 3- and 4-bromobenzenesulfonyl chlorides react nicely to afford arylated heteroarenes in moderate to high yields without cleav
AgONO-Assisted Direct C-H Arylation of Heteroarenes with Anilines
Gowrisankar, Saravanan,Seayad, Jayasree
supporting information, p. 12754 - 12758 (2015/03/30)
A novel copper-catalyzed C-H arylation of heteroarenes with anilines by an in situ diazonium reaction is established by using silver nitrite (AgONO) as an unconventional nitrosating reagent under acid-free conditions. It provides a complementary approach for the C-H arylation of electron-rich heteroarenes with aromatic amines affording a variety of heterobiaryls in moderate to good yields.
Room-temperature arylation of arenes and heteroarenes with diaryliodonium salts by photoredox catalysis
Liu, Yu-Xia,Xue, Dong,Wang, Jia-Di,Zhao, Cong-Jun,Zou, Qing-Zhu,Wang, Chao,Xiao, Jianliang
supporting information, p. 507 - 513 (2013/04/10)
Aryl radicals produced by irradiation of diaryliodonium salts with visible light under the catalysis of [Ru(bpy)3]2+ undergo coupling with a wide range of arenes and heteroarenes, affording various biaryls through direct C-H arylation at room temperature. Georg Thieme Verlag Stuttgart · New York.
Synthesis and structure-activity relationship studies of 3-biaryl-8-oxabicyclo[3.2.1]octane-2-carboxylic acid methyl esters
Torun, Lokman,Madras, Bertha K.,Meltzer, Peter C.
experimental part, p. 2762 - 2772 (2012/05/20)
Stille cross coupling protocols were utilized for the synthesis of 3-(biaryl)-8-oxabicyclo[3.2.1]oct-2-ene-2-carboxylic acid methyl esters, which furnished products in high yields where in some cases Suzuki coupling under the conditions utilized provided complex reaction mixture. Samarium iodide reduction of the resulting coupling products produced both of the 2β-carbomethoxy-3- biaryl-8-oxabicyclo[3.2.1]octane diastereomers and the 2α-carbomethoxy-3- biaryl-8-oxabicyclo[3.2.1]octane diastereomers. Among the series synthesized, the benzothiophene substituted compounds demonstrated significant binding profiles of inhibition of WIN 35,438 with 177-fold selectivity for DAT versus SERT.
