A “Green” Route to Perylene Dyes:  Direct Coupling Reactions of 1,8-Naphthalimide and Related Compounds under Mild Conditions Using a “New” Base Complex Reagent, <i>t</i>-BuOK/DBN

Abstract

The direct coupling reactions of 1,8-naphthalimide compounds efficiently occurred at 130 or 170 °C without the intervention of the leuco form dyes in the presence of base complex reagent, t-BuOK/1,5-diazabicyclo[4.3.0]non-5-ene (DBN), to give the corresponding perylene dyes in good yields with >95% purities. A possible mechanistic speculation for these oxidative coupling reactions is briefly discussed