ChemInform Abstract: Reactions of Perfluorocycloimines with (Polyfluoroalkoxy)trimethylsilanes and Polyfluoroalkyltrifluoromethanesulfonates

The reactions of F -(5,6-dihydro-2 H -1,4-oxazine) and F -(3,4-dihydro-2 H -pyrrole) were investigated using two series of reagents: one is the polyfluoroalkylating agent RfOSO 2 CF 3 and the other is the (polyfluoroalkoxy)trimethylsilane RfOSi(CH 3 ) 3 . Systematic study with polyfluoroalkyl groups such as CF 3 CH 2 , C 2 F 5 CH 2 , CHF 2 CH 2 , and (CF 3 ) 2 CH revealed that the regio-chemistry, isomer distribution, product distribution between mono-, di-, and tri-substituted products and even the reaction pathways were subtly changed by the structure of these fluoro substituents as well as by the reagent stoichiometry. A notable substitution effect was found in the reaction of F -(5,6-dihydro-2 H -1,4-oxazine): substitution at the 3-position prevented the N -polyfluoroalkylation by CF 3 CH 2 OSO 2 CF 3 . No particular difference was found between the two different heterocyclic systems in contrast with the reaction of these heterocyclic systems with C 6 F 5 Si(CH 3 ) 3 . The discussion about the reaction mechanisms for both reagents are included.