Reassembly and functionalization of N-CF3 pyridinium salts: synthesis of nicotinaldehydes

Abstract

Reassembly and functionalization of N-CF₃ pyridinium salts are reported. The cascade is initiated by hydrolytic ring-opening of N-CF₃ pyridinium salts, followed by defluorination, intramolecular nucleophilic addition, intermolecular nucleophilic substitution, and dehydrofluorination. The reaction exhibits tolerance to various O/N/S nucleophiles and provides a novel and efficient method for the construction of 2-functionalized nicotinaldehydes.