24257-29-2Relevant 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.
Room-Temperature Direct β-Arylation of Thiophenes and Benzo[b]thiophenes and Kinetic Evidence for a Heck-type Pathway
Colletto, Chiara,Islam, Saidul,Juliá-Hernández, Francisco,Larrosa, Igor
supporting information, p. 1677 - 1683 (2016/02/20)
The first example of a regioselective β-arylation of benzo[b]thiophenes and thiophenes at room temperature with aryl iodides as coupling partners is reported. This methodology stands out for its operational simplicity: no prefunctionalization of either st
Eco-friendly solvents for palladium-catalyzed desulfitative C-H bond arylation of heteroarenes
Hfaiedh, Anoir,Yuan, Kedong,Ben Ammar, Hamed,Ben Hassine, Bechir,Soulé, Jean-Fran?ois,Doucet, Henri
, p. 1794 - 1804 (2015/06/02)
Herein, we report the Pd-catalyzed regioselective direct arylation of heteroarenes in which benzenesulfonyl chlorides are used as coupling partners through a desulfitative cross-coupling that can be performed in diethyl carbonate (DEC) or cyclopentyl methyl ether (CPME) as green and renewable solvents or even in neat conditions instead of dioxane or dimethylacetamide (DMA). Under these solvent conditions, the reaction proceeds with a wide range of heteroarenes. C2- or C5-arylated products were obtained with furan and pyrrole derivatives. Benzofuran was also arylated regioselectively at the C2-position, whereas the reaction proceeds selectively at the C3- or C4-positions if thiophenes and benzothiophenes are used. Moreover, in some cases, especially with 1-methylindole, solvent-free conditions afforded better regioselectivities and/or yields than the reaction performed in the presence of solvents.
Pyridylidene ligand facilitates gold-catalyzed oxidative C-H arylation of heterocycles
Hata, Kazuhiro,Ito, Hideto,Segawa, Yasutomo,Itami, Kenichiro
supporting information, p. 2737 - 2746 (2016/04/01)
Triaryl-2-pyridylidene effectively facilitates the gold-catalyzed oxidative C-H arylation of heteroarenes with arylsilanes as a unique electron-donating ligand on gold. The employment of the 2-pyridylidene ligand, which is one of the strongest electron-donating N-heterocyclic carbenes, resulted in the rate acceleration of the C-H arylation reaction of heterocycles over conventional ligands such as triphenylphosphine and a classical N-heterocyclic carbene. In situ observation and isolation of the 2-pyridylidene-gold(III) species, as well as a DFT study, indicated unusual stability of gold(III) species stabilized by strong electron donation from the 2-pyridylidene ligand. Thus, the gold(I)-to-gold(III) oxidation process is thought to be facilitated by the highly electron-donating 2-pyridylidene ligand.
Benzenesulfonyl chlorides: New reagents for access to alternative regioisomers in palladium-catalysed direct arylations of thiophenes
Yuan, Kedong,Doucet, Henri
, p. 392 - 396 (2014/01/06)
The palladium-catalysed coupling of benzenesulfonyl chlorides with thiophene derivatives allows regioselective access to β-arylated thiophenes. The reaction proceeds with easily accessible catalyst, base and substrates, without oxidant or ligand and tolerates a variety of substituents on both the benzene and thiophene moieties.
Pd-catalyzed β-selective direct C-H bond arylation of thiophenes with aryltrimethylsilanes
Funaki, Kenji,Sato, Tetsuo,Oi, Shuichi
supporting information, p. 6186 - 6189 (2013/02/23)
Direct arylation of thiophenes and benzothiophenes with aryltrimethylsilanes was effectively catalyzed by PdCl2(MeCN) 2 in the presence of CuCl2 as an oxidant. The reaction preferentially occurred at the β-position of both
5-HYDROXYPYRIMIDINE-4-CARBOXAMIDE COMPOUND
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Page/Page column 62, (2011/05/16)
The present invention provides compounds which promote erythropoietin production. Compounds represented by the following general formula (1) or pharmacologically acceptable salts thereof are provided: [wherein, R1 represents a group —X-Q1, X-Q1-Y-Q2 or X-Q1-Y-Q2-Z-Q3, X represents a single bond, —CH2— or the like, Q1 represents a monocyclic or bicyclic heterocyclic group which may have substituent(s), Y represents a single bond, —CH2—, or the like, Q2 represents a monocyclic or bicyclic hydrocarbon ring group which may have substituent(s) or a monocyclic or bicyclic heterocyclic group which may have substituent(s), Z represents a single bond, —CR11R12— or the like, R11 and R12 each independently represents a hydrogen atom, a halogen atom or the like, Q3 represents a phenyl group which may have substituent(s), a C3-C7 cycloalkyl group which may have substituent(s), a C3-C7 cycloalkenyl group which may have substituent(s) or a monocyclic or bicyclic heterocyclic group which may have substituent(s), R2 represents a C1-C3 alkyl group or the like, and R3 represents a hydrogen atom or a methyl group].
