钯催化的芳基C—H键三氟甲硫基化反应  

Palladium-Catalyzed Trifluoromethylthiolation of Arenes via C—H Activation

作　　者：徐佳斌[1] 陈品红[2] 叶金星[1] 刘国生[2] 

机构地区：[1]制药工程与过程化学研究中心华东理工大学药学院,上海200237 [2]金属有机化学国家重点实验室中国科学院上海有机化学研究所,上海200032

出　　处：《化学学报》2015年第12期1294-1297,共4页Acta Chimica Sinica

基　　金：科技部(No.973-2015CB856600);国家自然科学基金(Nos.21225210;21421091;21472219);上海市科学技术委员会(No.12ZR1453400)资助~~

摘　　要：报道了二价钯催化的高选择性芳基C—H键的三氟甲硫基化反应,其中稳定的三氟甲硫基苯胺2a作为三氟甲硫基试剂,醋酸钯作为催化剂,苯甲酰氯和醋酸银作为添加剂,反应在DMF中120℃条件下实现的.各种取代的吡啶都可以作为该反应的导向基团.反应中苯甲酰氯的添加对活化三氟甲硫基苯胺2a起着关键作用.该反应为合成邻位三氟甲硫基取代苯类衍生物提供了高效方便的方法.Fluorinated organic compounds are widely used as pharmaceuticals, agrochemicals and materials. Among them, the trifluoromethylthio（-SCF3） compounds has attracted much attention owning to its strong electron-withdrawing nature and high lipophilicity. Therefore, the development of new trifluoromethylthiolation methods has attracted great interest in synthetic organic chemistry. Traditional approaches for the synthesis of trifluoromethylthiolated arenes include halogen-fluorine exchange and the trifluoromethylation of sulfur-containing compounds such as disulfides, thiols, which suffer from poor functional compatibility and yield. Recent progress on the transition metal-catalyzed directing trifluoromethylthiolation using SCF3 reagents provided an efficient approach to the target. Herein, we reported a Pd（II）-catalyzed highly selective C—H trifluoromethylthiolation of arenes. Different type of pyridines could be used as efficient directing groups for this reaction. In this reaction, benzoyl chloride was found to be crucial to activate the trifluoromethanesulfanamide 2a. It provides an efficient way for the synthesis of ortho-SCF3 substituted arenes in high yields. A representative procedure for this reaction is as following： To a 10 m L glass tube, Pd（OAc）2（4.4 mg, 0.02 mmol）, Ag OAc（33 mg, 0.2 mmol）, Ph NHSCF3（50 μL, 0.5 mmol）, substrate（0.2 mmol） and Ph COCl（58 μL, 0.5 mmol） were dissolved in dry DMF（1 m L） under N2 atmosphere. The tube was sealed and the mixture was stirred at 120 ℃ for 12 h, and then cooled to room temperature. The mixture was concentrated and purified by column chromatography on silica gel with a gradient eluent of petroleum ether and ethyl acetate（range from 15∶1 to 4∶1） to provide the products in 62%~91% yields.

关 键 词：钯催化 C—H键活化 三氟甲硫基化 三氟甲硫基胺 

分 类 号：O621.251[理学—有机化学]