- Tetrafluorine-containing ketones and acetoacetates: Synthesis and mechanistic study
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Addition of trimethylsilyl trifluoroacetate to the carbanions of α-fluorobenzyl-phosphonate (3) or diisopropyl(fluorocarbethoxymethyl) phosphonate (9) formed the corresponding intermediates [CF3C(O)CFPh] -Li+ (10) and [CF3C(O)CFCO2Et] -Li+ (11), respectively. Subsequent protonation, alkylation or allylation of 10 and 11 afforded trifluoromethyl fluorobenzyl ketones 12 and ethyl 2,4,4,4-tetra-fluoroacetoacetates 13. Based on the results obtained, a plausible mechanism was proposed.
- Tsai, Hou-Jen,Hsieh, Chi-Wei
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p. 749 - 757
(2008/03/11)
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- Application of fluorocarbethoxy-substituted phosphonate: A facile entry to substituted 2-fluoro-3-oxoesters
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Diethyl(fluorocarbethoxymethyl)phosphonate 1a or diisopropyl(fluorocarbethoxymethyl)phosphonate 1b, prepared from triethyl phosphite or triisopropyl phosphite with ethyl bromofluoroacetate, react with n-butyllithium in THF to give the corresponding phosphonate carbanions [(RO)2P(O)CFCO2Et]-Li+ 2a (R = Et) and 2b (R = i-Pr). Addition of trimethylsilyltrifluoroacetate CF3C(O)OSiMe3 to a THF solution of phosphonate carbanions formed the enolate of ethyl trifluoroacetylfluoroacetate [CF3C(O)CFCO2Et]-Li+ 3. Subsequent protonation, alkylation or allylation of the enolate afforded substituted 2,4,4,4-tetrafluoro-3-oxoesters CF3C(O)CFR1CO2Et 10.
- Tsai, Hou-Jen
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