King of the ring: S‐(trifluoromethyl)benzo[b]thiophenium salts 1, as analogues of Yagupolskii–Umemoto type reagents, were synthesized by novel triflic acid catalyzed intramolecular cyclization of ortho‐ethynylaryltrifluoromethylsulfanes 2. 1 j is especially useful for the electrophilic trifluoromethylation of β‐ketoesters and dicyanoalkylidenes.
环中之王:S-(三
氟甲基)苯并[b]
噻吩盐1作为Yagupolskii–Umemoto型试剂的类似物,是通过新颖的
三氟甲磺酸催化的邻
乙炔基芳基三
氟甲基
硫烷2的分子内环化反应合成的。1 j对于亲电性特别有用β-
酮酸酯和二
氰基亚烷基的三
氟甲基化。