title: Environmentally-Safe Conditions for a Palladium-Catalyzed Direct C3-Arylation with High Turn Over Frequency of Imidazo[1,2-b]pyridazines Using Aryl Bromides and Chlorides.
abstract: Pd(OAc)2 was found to catalyze very efficiently the direct arylation of imidazo[1,2-b]pyridazine at C3-position under a very low catalyst loading and phosphine-free conditions. The reaction can be performed in very high TOFs and TONs employing as little as 0.1-0.05 mol % catalyst using a wide range of aryl bromides. In addition, some electron-deficient aryl chlorides were also found to be suitable substrates. Moreover, 31 examples of the cross couplings were reported using green, safe, and renewable solvents, such as pentan-1-ol, diethylcarbonate or cyclopentyl methyl ether, without loss of efficiency.
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 263 avenue du Général Leclerc, 35042, Rennes Cedex, France.|Laboratoire d'hydrométallurgie et chimie inorganique moléculaire Faculté de Chimie U.S.T.H.B., Bab-Ezzouar, 16042, Alger, Algeria)16042.
authors.forename: Sabah
authors.initials: S
authors.lastname: Chikhi
authors.affiliation: Laboratoire d'hydrométallurgie et chimie inorganique moléculaire Faculté de Chimie U.S.T.H.B., Bab-Ezzouar, 16042, Alger, Algeria)16042.
authors.forename: Safia
authors.initials: S
authors.lastname: Djebbar
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 263 avenue du Général Leclerc, 35042, Rennes Cedex, France. jean-francois.soule@univ-rennes1.fr.
authors.forename: Jean-François
authors.identifier: http://orcid.org/0000-0002-6593-1995
authors.initials: JF
authors.lastname: Soulé
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 263 avenue du Général Leclerc, 35042, Rennes Cedex, France. henri.doucet@univ-rennes1.fr.
authors.forename: Henri
authors.initials: H
authors.lastname: Doucet
keywords: aryl halides; green solvents; heterocycles; palladium; phosphine-free