Low-temperature 19F NMR spectroscopy of 1-fluoro-1-lithioethenes - Stability, shifts and unexpected coupling constants
Half-lives and fluorine atom shifts of stabilized 1-fluoro-l-lithioethenes bearing hydrogen, fluorine, phenyl, and/or dimethylphenylsilyl groups in the β-positions have been determined by a low-temperature 19F NMR spectroscopy. Some 1-fluoro-1-lithioethenes displayed an exceptionally low value of the trans-3JFF coupling constant. Stereoselectivity of carbenoid formation, as well as an effect of configuration on the stability is discussed.
Kvicala, Jaroslav,Hrabal, Richard,Czernek, Jiri,Bartosova, Ivana,Paleta, Oldrich,Pelter, Andrew
p. 211 - 218
(2007/10/03)
Toward (Z)-selective Horner-Wadsworth-Emmons reaction of aldehydes with 2-fluoro-2-diethylphosphonoacetic acid
The stereoselective Horner-Wadsworth-Emmons reaction of aldehydes with 2-fluoro-2-diethylphosphonoacetic acid utilizing i-PrMgBr afforded (Z)-α-fluoro-α,β-unsaturated carboxylic acids as the major products.