Synthesis of CF<sub>3</sub>-Substituted Olefins by Julia-Kocienski Olefination Using 2-[(2,2,2-Trifluoroethyl)sulfonyl]benzo[<i>d</i>]thiazole as Trifluoromethylation Agent
作者:Andreas Hafner、Tobias S. Fischer、Stefan Bräse
DOI:10.1002/ejoc.201301070
日期:2013.12
A modified Julia–Kocienski protocol was investigated for the synthesis of CF3-substituted terminal olefins. By employing a simple one-step procedure, aldehydes were converted into the corresponding CF3-substituted olefins using 2-[(2,2,2-trifluoroethyl)sulfonyl]benzo[d]thiazole as the trifluoromethylation agent. This sulfone was prepared on a gram scale in two steps from inexpensive and commercially
研究了一种改进的 Julia-Kocienski 方案,用于合成 CF3 取代的末端烯烃。通过采用简单的一步法,使用 2-[(2,2,2-三氟乙基)磺酰基]苯并[d]噻唑作为三氟甲基化试剂,将醛转化为相应的 CF3 取代烯烃。这种砜是从廉价的市售三氟乙醇中分两步以克级规模制备的。Julia-Kocienski 烯化可耐受各种官能团,并以良好的收率获得三氟甲基化烯烃。然而,E/Z 选择性强烈依赖于底物,并且只能实现中等选择性。