title: Preparation of o-Fluorophenols from Nonaromatic Precursors: Mechanistic Considerations for Adaptation to Fluorine-18 Radiolabeling.
abstract: The preparation of fluorine-18 labeled o-fluorophenols at high specific activity is challenging and requires use of [(18)F]fluoride ion as the radioisotope source. As a novel, alternative approach, we found that treatment of α-diazocyclohexenones with Selectfluor and Et3N·3HF followed by HF elimination and tautomerization afforded o-fluorophenols regioselectively and rapidly. To adapt this chemistry to (18)F radiolabeling, using bromine electrophiles in place of Selectfluor gave the o-fluorophenol via an α-bromo-α-fluoroketone intermediate in lower but still reasonable yields.
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.
authors.forename: Norio
authors.initials: N
authors.lastname: Yasui
authors.affiliation: Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign , 405 North Mathews Avenue, Urbana, Illinois 61801, United States.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Mayne
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.
authors.forename: John A
authors.initials: JA
authors.lastname: Katzenellenbogen
mesh_terms: D020650:Combinatorial Chemistry Techniques; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D005462:Fluorine Radioisotopes; D006845:Hydrocarbons, Fluorinated; D010636:Phenols; C487839:2-fluorophenol