Pyridinium Salt Forming Rh(III)-Catalyzed Annulation Reaction of Secondary Allylamines with Internal Alkynes and Its Application to Surface Modification of a Mesoporous Material

A Rh­(III)-catalyzed C–H activation reaction has been developed for the preparation of pyridinium salts from secondary allylamines and internal alkynes. The pyridinium salts formed by this N-annulation reaction have interesting fluorescence properties. This protocol has been applied to the surface modification of mesoporous silica materials to generate functionalized silica that can be used for the detection of nitrobenzene.