Synthesis and Chemiexcitation of a Distinct Chemiluminescent Luminophore based on a Curcumin Scaffold

Natural fluorogenic dyes are composed of unique molecular structures that could be harnessed for the design of new chemiluminescent luminophores. Here we demonstrated how to simply transform an emissive curcumin scaffold into a novel chemiluminescent luminophore. An appropriate bromo-curcumin intermediate was synthesized as a substrate for a Stille cross-coupling reaction with an adamantyl-stannane reagent. This late-stage functionalization afforded in one step a curcumin enolether precursor that can then be oxidized with singlet oxygen to produce a curcumin chemiluminescent luminophore. This curcumin dioxetane luminophore produced an intense light signal with an emission spectrum that correlates with its curcumin scaffold. This is the first example of a chemiluminescent luminophore that is based on the emissive nature of the curcumin molecular structure. We expect that the method described herein would be useful for the synthesis of new chemiluminescent luminophores by transforming other known emissive dyes into dioxetane precursors via the Stille cross-coupling approach.