201221-71-8Relevant academic research and scientific papers
A facile one-pot synthesis of α-fluoro-α,β-unsaturated esters from alkoxycarbonylmethyltriphenylphosphonium bromides
Suzuki, Yumiko,Sato, Masayuki
, p. 1679 - 1681 (2007/10/03)
A convenient one-pot synthesis of α-fluoro-α, β-unsaturated esters from ethoxy- and tert- butoxycarbonylmethyltriphenylphosphonium bromide was developed. The fluorinated phosphoranes, generated in situ from alkoxycarbonylmethyltriphenylphosphonium bromides and 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor), undergo a Wittig reaction with aldehydes to yield α-fluoro-α,β-unsaturated esters with (Z)-selectivity.
Alkylation of (Fluorocarbethoxymethylene)-tri-n-butylphosphorane: A Facile Entry to α-Fluoroalkanoates
Thenappan, Alagappan,Burton, Donald J.
, p. 2311 - 2317 (2007/10/02)
(Fluorocarbethoxymethyl)trialkylphosphonium bromides 6, prepared from ethyl bromofluoroacetate and tertiary phosphines, react with n-butyllithium in THF to give the corresponding phosphoranes 7.Reaction of the pregenerated (fluorocarbethoxymethylene)tri-n-butylphosphorane 7a with primary alkyl iodides and activated alkyl bromides followed by in situ hydrolysis of the alkylated salts provides the fluoroalkanoates 9 in a one-pot reaction.In the case of secondary alkyl halides, no substitution was observed, the main reaction being decomposition of the phosphorane.However, the anion obtained from diisopropyl (fluorocarbethoxymethyl)phosphonate 10 b reacts with CH3CH(Ph)Br and (CH3)2CHI to afford the corresponding alkylated phosphonates in good yields.Displacement of the phosphonate moiety either by base-induced hydrolysis or by reduction was unsuccessful.
