title: Source of Selectivity in Oxidative Cross-Coupling of Aryls by Solvent Effect of 1,1,1,3,3,3-Hexafluoropropan-2-ol.
abstract: Solvents such as 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) with a high capacity for donating hydrogen bonds generate solvates that enter into selective cross-coupling reactions of aryls upon oxidation. When electric current is employed for oxidation, reagent effects can be excluded and a decoupling of nucleophilicity from oxidation potential can be achieved. The addition of water or methanol to the electrolyte allows a shift of oxidation potentials in a specific range, creating suitable systems for selective anodic cross-coupling reactions. The shift in the redox potentials depends on the substitution pattern of the substrate employed. The concept has been expanded from arene-phenol to phenol-phenol as well as phenol-aniline cross-coupling. This driving force for selectivity in oxidative coupling might also explain previous findings using HFIP and hypervalent iodine reagents.
authors.affiliation: Institut für Organische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz (Germany).
authors.forename: Bernd
authors.initials: B
authors.lastname: Elsler
authors.affiliation: Institut für Organische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz (Germany).
authors.forename: Anton
authors.initials: A
authors.lastname: Wiebe
authors.affiliation: Institut für Organische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz (Germany).
authors.forename: Dieter
authors.initials: D
authors.lastname: Schollmeyer
authors.affiliation: Evonik Industries AG, Paul-Baumann-Straße 1, 45772 Marl (Germany).
authors.forename: Katrin M
authors.initials: KM
authors.lastname: Dyballa
authors.affiliation: Evonik Industries AG, Paul-Baumann-Straße 1, 45772 Marl (Germany).|Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum (Germany).
authors.forename: Robert
authors.initials: R
authors.lastname: Franke
authors.affiliation: Institut für Organische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz (Germany). waldvogel@uni-mainz.de.
authors.forename: Siegfried R
authors.initials: SR
authors.lastname: Waldvogel
keywords: biaryls; cross-coupling; electrolysis; hydrogen bonds; solvent effects