2,4-Diaryl-1,1,1-trifluorobut-3-en-2-oles and their TMS-ethers in H2SO4 at room temperature in just 2 min are quantitatively cyclized into 1-aryl-3-trifluoromethyl-1H-indenes. The reaction proceeds through an intermediate formation of the corresponding CF3-allyl cations, which are cyclized regioselectively at the allyl carbon atom most remote from the CF3-group. The obtained CF3-indenes in solution
在室温下仅2分钟的时间内,将2,4-二芳基-1,1,1-三
氟丁-3-烯-2-烯烃及其TMS-醚在H 2 SO 4中定量环化成1-芳基-3-三
氟甲基- 1 H-
茚。该反应通过中间形成相应的CF 3-烯丙基阳离子进行,该中间体在最远离CF 3-基团的烯丙基碳原子上区域选择性地环化。将得到的CF 3-
茚在EtOAc溶液中,在
硅胶存在下,在室温下于4小时内定量异构化成3-芳基-1-三
氟甲基-1 H-
茚。