Regio- and Diastereo-Controlled (5 + 2) Cycloaddition of gem -Difluorocyclopropenes and Oxidopyridinium Ions

Abstract A method for the direct synthesis of 3,3-difluoro-9-azatricyclo[3.3.1.02,4]nonanes via a (5 + 2) cycloaddition between a gem-difluorocyclopropene and an oxidopyridinium ion is reported. This approach furnishes the products in moderate to good yields, with exclusive exo-selectivity and broad substrate compatibility. Its synthetic utility is further demonstrated by a gram-scale reaction and derivatization studies.