作者:Paolo Ricci、Tanatorn Khotavivattana、Lukas Pfeifer、Maurice Médebielle、John Richard Morphy、Véronique Gouverneur
DOI:10.1039/c6sc02790c
日期:——
catalyst is not required as the thiourea acts as a reductant, as well as serving as an S-source capable of adding to a C-centered radical. Mechanistic work comparing the reactivity of thiourea, urea, thioamide and thiol in the context of alkene trifluoromethylation demonstrates that in this series, the thiourea is unique for its ability to release CF3 radical from the Togni reagent, and to orchestrate trifluoromethylation
被硫脲取代的烯烃在室温下发生 C-CF 3反应,然后与 Togni 试剂和三氟乙酸 (TFA) 形成分子内 C-S 键;硫醇和硫代酰胺不适合该反应的硫源。这种反加成过程涉及 CF 3自由基,并提供 CF 3取代的噻唑啉和噻嗪用于医药应用。不需要金属或光氧化还原催化剂,因为硫脲充当还原剂,以及充当能够添加到以 C 为中心的自由基的 S 源。比较硫脲、脲、硫代酰胺和硫醇在烯烃三氟甲基化背景下的反应性的机理研究表明,在该系列中,硫脲的独特之处在于其释放 CF 3的能力从 Togni 试剂中提取自由基,并协调三氟甲基化,然后与活化和未活化的烯烃进行S-环化。