Directly Fused Highly Substituted Naphthalenes via Pd-Catalyzed Dehydrogenative Annulation of N,N-Dimethylaminomethyl Ferrocene Using a Redox Process with a Substrate

N,N-Dimethylaminomethyl ferrocenium could be generated in situ and served as a terminal oxidant for Pd-catalyzed directly dehydrogenative annulations of N,N-dimethylaminomethyl ferrocene and internal alkynes. This procedure utilized the redox activity of ferrocene and avoided adding an oxidant. A series of highly arylated naphthalenes functionalized by ferrocene were obtained in 53-81% yields.