摘要
介绍了一种烯烃在电催化条件下和三氟甲基亚磺酸钠盐反应生成α-三氟甲基酮的方法.三氟甲基亚磺酸钠盐通过在阳极氧化产生三氟甲基自由基进攻烯烃双键,再在空气氛围下氧化得到目标产物.该反应底物适用性良好,反应条件温和,和传统方法相比,利用电催化实现这一过程避免了过氧化剂或昂贵的光催化剂的使用.此外,用二氟甲基亚磺酸钠盐作为试剂时,还可以将该反应应用到α-二氟甲基酮的合成上.
The fluorine-containing group has a significant effect on properties such as lipophilicity,permeability,and meta-bolic stability of compounds.Therefore,the efficient introduction of fluorine-containing groups into pharmaceutical and ag-rochemical compounds,as well as functional organic materials,has become an important research field of chemistry.Un-doubtedly,new methodologies for the efficient and highly selective incorporation of fluorinated substituents into diverse mo-lecular structures continue to be in strong demand.During the past few years,electrosynthesis has been considered to be a practical and environmentally friendly synthetic tool.The application of electrochemical anodic oxidation in synthetic organ-ic chemistry has drawn increasing attention.Electrochemistry utilizes direct interaction of electrons from the anode and cathode with the nucleus,avoids using strong oxidants,and minimizes byproduct formation.Herein we describe an electro-chemical synthesis ofα-trifluoromethylated ketones from alkenes based on sodium trifluoromethanesulfinate.Sodium tri-fluoromethanesulfinate generates trifluoromethyl radicals through anodic oxidation to attack the carbon-carbon double bonds of alkenes,and then oxidized in air atmosphere to obtain the target compounds.The optimized reaction conditions of electro-chemical synthesis ofα-trifluoromethylated ketones are as follows:1 equiv.of alkenes,2 equiv.of sodium trifluoro-methanesulfinate,a mixture of CH_(3)CN/H_(2)O(V∶V=2∶1)as the solvent,2 equiv.of lithium perchlorate as electrolyte,CF3COOH as the sacrificial oxidant,graphite as the anode and platinum as the cathode,react at room temperature for 6 h under a constant current of 20 mA and air atmosphere,giving the correspondingα-trifluoromethyl-substituted ketones in 66%~84%yields.The reaction substrate has good applicability,and the reaction conditions are mild.Compared with the traditional methods,the electrocatalytic process avoids the use of peroxidants or expensive photocatalysts.In addition,this reaction can be applied to the synthesis ofα-difluoromethylated ketones when using sodium difluoromethanesulfinate instead of sodium trifluoromethanesulfinate.
作者
李珊
路俊欣
刘杰
蒋绿齐
易文斌
Li Shan;Lu Junxin;Liu Jie;Jiang Lvqi;Yi Wenbin(School of Chemistry and Chemical Engineering,Nanjing University of Science and Technology,Nanjing 210094;Shazhou Professional Institute of Technology,Zhangjiagang 215600)
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2024年第2期110-114,共5页
Acta Chimica Sinica
基金
国家自然科学基金(Nos.22078161,22108124)
中央高校基本科研业务费专项资金(Nos.30918011314,30922010403)
江苏省青蓝工程[苏教师函(2022)29号]
六大高峰人才资助。
关键词
电催化
自由基
三氟甲基亚磺酸钠
三氟甲基酮
electrocatalysis
free radical
sodium trifluoromethanesulfinate
trifluoromethy lated ketone
