NaBAr^F4-Catalyzed Oxidative Cyclization of 1,5-and 1,6-Diynes:Efficient and Divergent Synthesis of Functionalized γ-and δ-Lactams

Summary of main observation and conclusion An efficient NaBAr^F4-catalyzed oxidative cyclization of readily available 1,5-and 1,6-diynes has been developed.Importantly,this transition metal-free oxidative catalysis proceeds via a presumable Lewis acid-catalyzed SN2′pathway,which is distinct from the relevant oxidative rhodium and gold catalysis.This method leads to the facile and practical construction of a diverse range of synthetically useful γ- and δ-lactams in mostly good to excellent yields with broad substrate scope.