Phase-transfer-catalyst enabled enantioselective C–N coupling to access chiral boron-stereogenic BODIPYs

Abstract

Tetracoordinate boron-based fluorescent materials have shown extensively applications in chemistry, biology and materials science owing to their unique optoelectronic properties. However, constructing chiral boron-stereogenic fluorophores through practical and universal strategies remains rare and challenging. Herein, as a proof of concept, we report an enantioselective postfunctionalization of boron dipyrromethene dyes (BODIPYs), to acess boron-stereogenic BODIPYs in moderate to good yields with commendable enantioselectivity. Chiral BODIPYs have attracted increasing attention owing to not only their distinctively photophysical properties and applications in circularly polarized luminescence (CPL) materials, but also diversely structural modification. In this·work, we present a phase-transfer-catalyst enabled enantioselective C–N coupling reaction of BODIPYs with diverse nucleophiles. This method serves as a practical SNAr (nucleophilic aromatic substitution reaction) route to achieve a series of boron-stereogenic amido/amino BODIPYs as well as demonstrates their promising CD and·CPL·activities, excellent biocompatibility, and high specificities, showing potential applications as chiral fluorescent imaging agents.