PREPARATION OF TRIFLUOROMETHYL AND OTHER PERFLUOROALKYL COMPOUNDS WITH (PERFLUORALKYL)TRIMETHYLSILANES

The preparation of a variety of novel perfluoroalkyl-substituted compounds in high yields using easily prepared (perfluoroalkyl)trimethylsilanes (1a-c) is described. (Trifluoromethyl)-, (pentafluoroethyl)-, and (heptafluoropropyl)trimethylsilane, 1a-c, respectively, react readily with carbonyl compounds, such as aldehydes and ketones, by a fluoride-initiated catalytic process. Fluoride-initiated addition of 1 to a carbonyl group generates an oxyanionic species which then further catalyzes the reaction. Even enolizable carbonyl compounds react cleanly under the reaction conditions. A study of the scope of the reactivity of 1a toward other carbonyl groups in esters, lactones and an acid chloride was also carried out. Thus 1a reacts cleanly with five- and six-membered ring lactones. However, unactivated esters do not react under the reaction conditions. The acid chloride reacts with 1a to give a mixture of products.