Phenol derivatives were trifluoromethylated using copper/Togni reagent. Reaction in DMF selectively gave benzylic trifluoromethylation products, whereas aromatic trifluoromethylation products were obtained in t-BuOH.
Reactivity of a 10-I-3 Hypervalent Iodine Trifluoromethylation Reagent With Phenols
作者:Kyrill Stanek、Raffael Koller、Antonio Togni
DOI:10.1021/jo8014825
日期:2008.10.3
The reaction of the 10-I-3hypervalent iodine electrophilictrifluoromethylation reagent 1-trifluoromethyl-1,2-benziodoxol-3-(1H)-one (2) with 2,4,6-trimethylphenol, after deprotonation with NaH and in the presence of 18-crown-6 in a polar, nonprotic solvent, affords 1,3,5-trimethyl-2-(trifluoromethoxy)benzene (4) only as a byproduct. Trifluoromethylation occurs preferentially at the ortho- and para-positions