Synthesis of Indolizidine Derivatives Trifluoromethylated at Bridgehead Position via Acyl Iminium Ion Intermediates Derived from Ring-Chain Tautomerism of 5,5,5-Trifluoro-4-oxopentanoyl Arylethylamides
A variety of cyclic five-membered imides was trifluoromethylated in good to excellent chemical yields using (trifluoromethyl)trimethylsilane CF3SiMe3 under fluoride ion catalysis. The method was successfully applied to the stereoselective synthesis of trifluoromethylated bi- and tricyclic lactams which could serve as precursors for designed thrombin inhibitors.
Synthesis of Indolizidine Derivatives Trifluoromethylated at Bridgehead Position via Acyl Iminium Ion Intermediates Derived from Ring-Chain Tautomerism of 5,5,5-Trifluoro-4-oxopentanoyl Arylethylamides