Tetrafluorine-containing Ketones and Acetoacetates: Synthesis and Mechanistic Study

摘要

Addition of trimethylsilyl trifluoroacetate to the carbanions of α-fluorobenzyl-phosphonate (3) or diisopropyl(fluorocarbethoxymethyl)phosphonate (9) formed the corresponding intermediates [CF_3C(O)CFPh]~-Li~+ (10) and [CF_3C(O)CFCO_2Et]~-Li~+(11), respectively. Subsequent protonation, alkyla-tion 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.