1186369-07-2Relevant academic research and scientific papers
Solvent-free palladium-catalyzed direct arylation of heteroaromatics with aryl bromides
Bensaid, Souhila,Doucet, Henri
experimental part, p. 1559 - 1567 (2012/10/08)
Solvent is one of the major sources of waste in the course of catalyzed direct arylations. Some palladium-catalyzed direct arylations of heteroaromatics can be advantageously performed without any solvent. In the presence of palladium catalysts (1 mol%) and potassium acetate as the base, the direct 5-arylation of some thiazoles, thiophenes, furans, or pyrroles with aryl bromides as coupling partners proceeds highly regioselectively and in moderate to high yields. However, the use of these solvent-free conditions is limited to electron-deficient aryl bromides. Copyright
Ligand-less palladium-catalyzed direct 5-arylation of thiophenes at low catalyst loadings
Roger, Julien,Pozgan, Franc,Doucet, Henri
experimental part, p. 425 - 432 (2010/04/22)
Ligand-less Pd(OAc)2 provides a very efficient catalyst for the direct 5-arylation of thiophene derivatives. With this catalyst, a low palladium concentration (0.1-0.001 mol%) should be employed in order to obtain high yields of coupling products. At higher concentrations a fast formation of inactive "Pd black" generally occurs. Substrates/catalysts ratios up to 100000 can be employed with the most reactive aryl bromides. A very wide variety of functional groups is tolerated on both coupling partners. The major waste of this reaction is HBr associated with KOAc. Therefore this procedure is more economically and environmentally attractive than the traditional cross-coupling procedures employing organometallic derivatives.
