A Concise Route to Water-Soluble 2,6-Disubstituted BODIPY-Carbohydrate Fluorophores by Direct Ferrier-Type C-Glycosylation

Abstract

Novel, linker-free, BODIPY-carbohydrate derivatives containing sugar residues at positions C2 and C6 are efficiently obtained by, hitherto unreported, Ferrier-typeC-glycosylation of 8-aryl-1,3,5,7-tetramethyl BODIPYs with commercially available tri-O-acetyl-glucal followed by saponification. This transformation, which involves the electrophilic aromatic substitution (SEAr) of the dipyrrin framework with an allylic oxocarbenium ion, provides easy access to BODIPY-carbohydrate hybrids with excellent photophysical properties and a weaker tendency to aggregate in concentrated water solutions.