Development of a New Methodology for Dearomative Borylation of Coumarins and Chromenes and Its Applications to Synthesize Boron-Containing Retinoids

Dearomative borylation of coumarins and chromenes via conjugate addition represents a relatively unexplored and challenging task. To address this issue, herein, we report a new and general copper (I) catalyzed dearomative borylation process to synthesize boron-containing oxacycles. In this report, the borylation of coumarins, chromones, and chromenes comprising functional groups, such as esters, nitriles, carbonyls, and amides, has been achieved. In addition, the method generates different classes of potential boron-based retinoids, including the ones with oxadiazole and anthocyanin motifs. The borylated oxacycles can serve as suitable intermediates to generate a library of compounds.

Automated summary

A new and general copper (I) catalyzed dearomative borylation process for synthesizing boron-containing oxacycles is reported. Coumarins, chromones, and chromenes with functional groups such as esters, nitriles, carbonyls, and amides can be borylated using this method. The borylated oxacycles can serve as intermediates for generating a library of compounds, including potential boron-based retinoids with oxadiazole and anthocyanin motifs.