Facile generation of polyfluoro-1-(tosyloxy)prop-1-enyllithiums and their reaction with electrophiles. A new, efficient and convenient access to (Z)-1,1-di- and 1,1,1-tri-fluoro-3-(tosyloxy)alk-3-en-2-ones [Review]

摘要

Polyfluoro-1-(tosyloxy)prop-1-enyllithiums, generated by the reaction of polyfluoropropyl toluene-p-sulfonates or polyfluoroprop-1-enyl toluene-p-sulfonates with n-butyllithium, readily react with a variety of electrophiles, such as aldehydes, ketones, methyl trifluoromethanesulfonate, chlorotrimethylsilane and chlorotributylstannane, to give the corresponding coupling products in good yields. In particular, polyfluoro-2-(tosyloxy)but-2-enyl alcohols, obtained from the vinyllithiums and carbonyl compounds, undergo hydrolysis with concentrated sulfuric acid at-room temperature or 70 degrees C to afford the corresponding (Z)-1,1-di- or 1,1,1-tri-fluoro-3-(tosyloxy)alk-3-en-2-ones in good to excellent yields. [References: 127]