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Radical Arylation of Phenols, Phenyl Ethers, and Furans
Author(s) -
Wetzel Alexander,
Pratsch Gerald,
Kolb Roman,
Heinrich Markus R.
Publication year - 2010
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200902927
Subject(s) - chemistry , regioselectivity , phenols , alkoxy group , organic chemistry , phenethylamines , aryl , biphenyl , solvent , chloride , catalysis , stereochemistry , alkyl
Radical arylations of para ‐substituted phenols and phenyl ethers proceeded with good regioselectivity at the ortho position with respect to the hydroxy or alkoxy group. The reactions were conducted with arenediazonium salts as the aryl radical source, titanium(III) chloride as the reductant, and diluted hydrochloric acid as the solvent. Substituted biaryls were obtained from hydroxy‐ and alkoxy‐substituted benzylamines, phenethylamines, and aromatic amino acids. The methodology described offers a fast, efficient, and cost‐effective new access to diversely functionalized biphenyl alcohols and ethers. Free phenolic hydroxy groups, aromatic and aliphatic amines, as well as amino acid substructures, are well tolerated. Two examples for the applicability of the methodology are the partial synthesis of a β‐secretase inhibitor and the synthesis of a calcium‐channel modulator.