The reaction of fluoro-olefins (I) with hexafluoroacetone cyanohydrin (II) catalyzed by Et3N gives fluorinated 3-iminotetrahydrofurans (III), whose structures have been confirmed by spectral methods and various chemical transformations. A mechanism for the formation of products III is suggested including nucleophilic addition of an O-anion to a CC bond followed by intramolecular cyclization in the
Et 3 N催化的氟代烯烃(I)与六氟丙酮氰醇(II)的反应生成了氟化的3-亚氨基四氢呋喃(III),其结构已通过光谱法和各种化学转化得到了证实。提出了产物Ⅲ的形成机理,包括向C additionC键亲核加成O-阴离子,然后在中间的C-阴离子中通过CN基团进行分子内环化。
Electrophilic elimination of alkyl flourides from alkyl flouroalkenyl ethers
number of perfluoromethacrylic acid derivatives have been prepared by the elimination of alkyl fluoride from substituted alkoxyperfluoroisobutylenes through the action of Lewis acids. Adducts (11a,b) containing a mesomeric carbonium-cation and a tetrafluoroborate-anion were obtained by reacting aminoacetals of bis(trifluoromethyl)ketene with BF3.
A new approach to the synthesis of trifluoromethylated products of the [3,3]-sigmatropic rearrangement
作者:V. G. Andreev
DOI:10.1007/bf00698247
日期:1994.7
CH-acids of general formula CF3CH(X)CF3 (X = CF3, CO2R) react with 2,3-unsaturated alcohols in the presence of bases to give trifluoromethylated products of the [3,3]-sigmatropic rearrangement. These reactions provide a convenient method for the synthesis of 2-alkenyl-2-trifluoromethylmalonates.