用原位变温^(19)FNMR研究三氟甲磺酸根在苯乙烯不对称环丙烷化反应中的作用  

Study on the Role of Trifluoromethanesulfonate Ion in Asymmetric Cyclopropanation of Styrene by in Situ Variable Temperature 19 F NMR

作　　者：李琛[1] 张维萍[1] 刘秀梅[1] 姚小泉[1] 陆世维[1] 韩秀文[1] 包信和[1] 

机构地区：[1]中国科学院大连化学物理研究所催化基础国家重点实验室,大连116023

出　　处：《催化学报》2001年第2期154-156,共3页

摘　　要：The role of trifluoromethanesulfonate ion (OTf -) in asymmetric cyclopropanation of styrene catalyzed by ruthenium complex of chiral N, P ligand is investigated by in situ variable temperature 19 F NMR. The temperature of NMR experiment varies from 243 K to 283 K. After ethyl diazoacetate and styrene are added into the catalytic system, the process that the OTf - leaves from the central metal is observed from the change of the 19 F NMR spectra. Owing to the weakly coordinating behavior, trifluoromethanesulfonate ion can be easily removed from the central metal and replaced by substrates to form the reactive intermediate during the reaction. So that the catalytic reactivity can be improved greatly when the silver trifluoromethanesulfonate is added to the catalytic system.The role of trifluoromethanesulfonate ion (OTf -) in asymmetric cyclopropanation of styrene catalyzed by ruthenium complex of chiral N, P ligand is investigated by in situ variable temperature 19 F NMR. The temperature of NMR experiment varies from 243 K to 283 K. After ethyl diazoacetate and styrene are added into the catalytic system, the process that the OTf - leaves from the central metal is observed from the change of the 19 F NMR spectra. Owing to the weakly coordinating behavior, trifluoromethanesulfonate ion can be easily removed from the central metal and replaced by substrates to form the reactive intermediate during the reaction. So that the catalytic reactivity can be improved greatly when the silver trifluoromethanesulfonate is added to the catalytic system.

关 键 词：弱配位阴离子 三氟甲磺酸根 苯乙烯 环丙烷化反应 不对称催化 钌配合物 催化剂 原位变温氟19核磁共振 

分 类 号：O643[理学—物理化学] O657.2[理学—化学]