141778-53-2Relevant articles and documents
Exploring Green Solvents Associated to Pd/C as Heterogeneous Catalyst for Direct Arylation of Heteroaromatics with Aryl Bromides
Mao, Shuxin,Shi, Xinzhe,Soulé, Jean-Fran?ois,Doucet, Henri
, p. 3306 - 3317 (2018/08/03)
Metal residues are certainly one of the major sources of contamination of products in metal-catalyzed direct arylation reactions. We found that the use of only 1 mol% of the heterogeneous catalyst Pd/C promotes very efficiently the direct arylations of most heteroaromatics. In the presence of this catalyst and potassium acetate as the base, the direct arylation of thiophenes, furans, pyrroles, thiazoles, imidazoles or isoxazoles, using aryl bromides as coupling partners, proceeds highly regioselectively and in moderate to very high yields. With several heteroarenes both electron-deficient and electron-rich aryl bromides were tolerated; moreover, with the most reactive heteroarenes, the Pd/C catalyst tolerated green solvents such as diethyl carbonate, 3-methylbutan-1-ol and pentan-1-ol, affording a synthetic scheme with low environmental impact. (Figure presented.).
New Liquid Crystalline Compounds Based on Thiophene
Brettle, Roger,Dunmur, David A.,Marson, Charles M.,Pinol, Milagros,Toriyama, Kazuhisa
, p. 613 - 616 (2007/10/02)
A homologous series of 2-alkyl-5-(4'-cyanophenyl)thiophenes has been prepared and shown to have improved properties for use in liquid crystal displays.The thiophene ring is prepared from a 1-(4'-bromophenyl)-1,4-dioxoalkane, constructed using the Stetter procedure, by the action of Lawessons reagent, and the cyano-group is finally introduced using a copper(I)-mediated exchange reaction.
