Nucleophilic trifluoromethylation with CF_(3)H/LiHMDS: probing the nucleophilic reactivity of LiCF_(3) species  

作　　者：Yangfan Liu Xiu Wang Chuanfa Ni Jinbo Hu 

机构地区：[1]College of Chemistry,Central China Normal University,Wuhan 430079,China [2]Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials,Shanghai Institute of Organic Chemistry,University of Chinese Academy of Sciences,Chinese Academy of Sciences,Shanghai 200032,China

出　　处：《Science China Chemistry》2025年第2期505-512,共8页中国科学(化学英文版)

基　　金：support of this work by the National Key Research and Development Program of China(2021YFF0701700);the National Natural Science Foundation of China(22271299,22261132514 and 22301308);the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0590000);the Natural Science Foundation of Shandong Province(ZR2021LFG006 and ZR2023LFG003);the Shandong Dongyue Polymer Material Co.Ltd.is gratefully acknowledged。

摘　　要：The nucleophilic trifluoromethylation involving trifluoromethyllithium(LiCF_(3))species has been an open question since Haszeldine attempted to prepare LiCF_(3) in 1949.Indeed,LiCF_(3) has been used for electrophilic difluoromethylene transfer processes(via elimination of fluoride ions)since 2010.Herein,we demonstrated that by using a polar solvent such as dimethylformamide(DMF)or hexamethylphosphoramide(HMPA)as the lithium chelator,the in situ deprotonation of fluoroform(HCF_(3))with lithium hexamethyldisilazide(LiHMDS)could generate a tamed LiCF_(3) species that is sufficiently persistent to undergo nucleophilic trifluoromethylation reaction.The nucleophilic reactivity of LiCF_(3) species was probed with several electrophiles,including arylsulfonyl fluorides,diaryl ketones,and silyl chlorides.The synthetic utility of this method is demonstrated with the efficient synthesis of highly valuable triflones that are otherwise difficult to synthesize from HCF_(3) using potassium or sodium bases.This work not only showcases a new protocol for the utilization of fluoroform(an industrial waste with high global warming potential)as the trifluoromethylation reagent,but also provides intriguing insights into the harnessing of nucleophilic reactivity of the transient LiCF_(3) species.

关 键 词：nucleophilic trifluoromethylation trifluoromethy llithium fluorinated carbanion negative fluorine effect fluorinated carbenoid 

分 类 号：O62[理学—有机化学]