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-3 hypervalent iodine electrophilic trifluoromethylation 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
NaH去质子后,在10-I-3高价碘亲电子三氟甲基化试剂1-trifluoromethyl-1,2-benziodoxol-3-(1H)-one(2)与2,4,6-三甲基苯酚的反应中在极性非质子溶剂中存在18-crown-6,仅提供1,3,5-三甲基-2-(三氟甲氧基)苯(4)作为副产物。三氟甲基化优先发生在芳族核的邻位和对位,从而得到相应的三氟甲基环己二酮5和6。如果邻位和/或对位不被取代,则可获得芳族亲电取代的相应产物以中等收率,例如从4-叔丁基苯酚(10)中得到2-三氟甲基-4-叔丁基苯酚(10a)。