- 作者: 蔡厚仁
- 作者服務機構: Department of Applied Chemistry, Chung Cheng Institute of Technology, Taiwan, R.O.C
- 中文摘要: The anion [(EtO)2P(O)CFCO2Et]¯Li+, pregenerated from its precursor diethyl (carboethoxy-fluoromethyl)phosphonate (EtO)2P(O)CFHCO2Et and n-butyllithium, was added via syringe to a THF solution of ethyl oxalyl chloride to yield an acylated phosphonate (EtO)2P(O)CF(COCO2Et)CO2Et. In situ reaction with Grignard reagents RMgX produces the α-fluorodiesters (E,Z)-R(CO2Et)C=CFCO2Et in good yields. In contrast, addition of ethyl oxalyl chloride to a THF solution of diethyl (carboethoxy-fluoromethyl)phosphonate anion gives an isolated intermediate (EtO)2P(O)CFCO2Et(CO2Et)C=CFCO2Et. Subsequent reaction of this isolated intermediate with Grignard reagents also affords a one-pot synthesis of the α-fluorodiesters with high E-stereoselectivity. The E-stereoselectivity increases when HMPT or DMPU is used as a cosolvent in the preparation of diethyl 2-fluoro-3-phenylfumarate (E,Z)-Ph(CO2Et)C=CFCO2Et.
- 英文摘要: --
- 中文關鍵字: Fluorophosphonates; Acylation; Cosolvent; Grignard Reagent; Stereoselectivity
- 英文關鍵字: 氟化膦酸鹽;醯化;共溶劑;格林那試劑;立體選擇性