Progress Towards the Synthesis of Fluorescent Tröger’s bases With a Chiral Bridge

Abstract

Julius Tröger first synthesized Tröger’s base in 1887. The compound is obtained by the reaction between formalin and p-toluidine in the presence of concentrated hydrochloric acid. The synthesis of the first fluorescent Tröger’s bases based on the highly fluorescent 4-amino-1,8-naphthalimide fluorophore was reported in 2005. Tröger’s bases are ^-shaped chiral molecules that comprise two possible enantiomers. The molecules are C2 symmetric, and have well defined exo (convex) and endo (concave) surfaces. The cavity of the molecule provides an ideal location for the construction of the chiral host molecule.