title: Metal- and reagent-free highly selective anodic cross-coupling reaction of phenols.
abstract: The direct oxidative cross-coupling of phenols is a very challenging transformation, as homo-coupling is usually strongly preferred. Electrochemical methods circumvent the use of oxidizing reagents or metal catalysts and are therefore highly attractive. Employing electrolytes with a high capacity for hydrogen bonding, such as methanol with formic acid or 1,1,1,3,3,3-hexafluoro-2-propanol, a direct electrolysis in an undivided cell provides mixed 2,2'-biphenols with high selectivity. This mild method tolerates a variety of moieties, for example, tert-butyl groups, which are not compatible with other strong electrophilic media but vital for later catalytic applications of the formed products.
authors.affiliation: Institut für Organische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz (Germany) http//www.chemie.uni-mainz.de/OC/AK-Waldvogel/
authors.forename: Bernd
authors.initials: B
authors.lastname: Elsler
authors.forename: Dieter
authors.initials: D
authors.lastname: Schollmeyer
authors.forename: Katrin Marie
authors.initials: KM
authors.lastname: Dyballa
authors.forename: Robert
authors.initials: R
authors.lastname: Franke
authors.forename: Siegfried R
authors.initials: SR
authors.lastname: Waldvogel
mesh_terms: D004566:Electrodes; D007202:Indicators and Reagents / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D010636:Phenols / Q000737:chemistry*
chemical_list: D007202:Indicators and Reagents; D008670:Metals; D010636:Phenols
keywords: CC coupling; anodic biaryl synthesis; green chemistry; oxidative coupling; phenol cross-coupling