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Regioselective Monobromination of Free and Protected Phenols
Author(s) -
Pla Daniel,
Albericio Fernando,
Álvarez Mercedes
Publication year - 2007
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200600971
Subject(s) - chemistry , regioselectivity , reagent , halogenation , electrophilic substitution , electrophile , phenols , organic chemistry , electrophilic aromatic substitution , n bromosuccinimide , solvent , reaction conditions , substitution reaction , medicinal chemistry , catalysis
A comparative study of the advantages of using THF compared with DMF in regioselective monobromination reactions of highly activated polyphenols, their ethers, and their tert ‐butyl carbonate derivatives under mild conditions is described. Bromination with the common reagent N ‐bromosuccinimide in polar solvents provided an easy and fast approach to aromatic electrophilic substitution at the most electronically favored positions with respect to O ‐substituents. Tight control of the reaction temperature as well as short reaction times afforded better isolated yields (from 70 % to quantitative) of bromides when THF was used as the solvent instead of the classically used DMF. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)