Addition of phenols to perfluorovinyl ethers. Protonation and halogenation of carbanionic intermediates
摘要:
Fluorinated ethers ArOCF2CFHORf are obtained in good yield by base-catalyzed addition of phenols to perfluoroalkyl vinyl ethers, CF2=CFORf (Rf = C3F7, C3F7OCF(CF3)CF2, CH3O2CCF2CF2OCF(CF3)CF2). Reaction of sodium phenoxides with fluorinated vinyl ethers and hexachloroethane affords chlorinated ethers ArOCF2CFClORf. Treatment of BrCF2CFBrOC3F, with sodium phenoxide in the presence of CF2=CFOC3F7 gives PhOCF2CFBrOC3F7 in high yield at room temperature, probably by an anionic chain mechanism. Sodium phenoxide reacts cleanly with CF2=CFOC3F7 in the absence of an electrophile to give a 1:1 cis-trans mixture of olefins PhOCF=CFOC3F7. NMR chemical shifts of the OCF2CFHORf group proton shows an unusually large solvent dependence.
Addition of phenols to perfluorovinyl ethers. Protonation and halogenation of carbanionic intermediates
作者:Andrew E. Feiring、Edward R. Wonchoba
DOI:10.1021/jo00052a008
日期:1992.12
Fluorinated ethers ArOCF2CFHORf are obtained in good yield by base-catalyzed addition of phenols to perfluoroalkyl vinyl ethers, CF2=CFORf (Rf = C3F7, C3F7OCF(CF3)CF2, CH3O2CCF2CF2OCF(CF3)CF2). Reaction of sodium phenoxides with fluorinated vinyl ethers and hexachloroethane affords chlorinated ethers ArOCF2CFClORf. Treatment of BrCF2CFBrOC3F, with sodium phenoxide in the presence of CF2=CFOC3F7 gives PhOCF2CFBrOC3F7 in high yield at room temperature, probably by an anionic chain mechanism. Sodium phenoxide reacts cleanly with CF2=CFOC3F7 in the absence of an electrophile to give a 1:1 cis-trans mixture of olefins PhOCF=CFOC3F7. NMR chemical shifts of the OCF2CFHORf group proton shows an unusually large solvent dependence.