Noritaka Kasai, Ryoko Maeda, H. Furuno
Sep 27, 2012
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Influential Citations
21
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Journal
Synthesis
Abstract
Abstract (E)-Diphenyl-β-(trifluoromethyl)vinylsulfonium triflate, readily prepared from 2-bromo-3,3,3-trifluoroprop-1-ene in two steps, undergoes double alkylation with active methylene compounds in dimethyl sulfoxide or ethyl acetate, in an open vessel at room temperature, to provide the corresponding trifluoromethylated cyclopropane derivatives in excellent yields. The cyclopropane, ethyl 1-cyano-2-(trifluoromethyl)cyclopropanecarboxylate is subjected to a ring-opening reaction followed by cyclization to afford a trifluoromethylated dihydroaminothiophene, which on oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone furnishes the corresponding trifluoromethylated aminothiophene in a high 88% yield.