Photoredox-catalyzed bisarylation of bromonitroalkanes enabled by the dual role of nitro functionality: synthesis of bis(indolyl)methanes as promising α-glucosidase inhibitors†

Disclosed herein is an interesting photoredox catalysis for the direct bisarylation of bromonitroalkanes with 2-arylindoles to provide a simplified synthetic route to 3,3′-diindolylmethane (DIM) derivatives, where the nitro functionality plays a dual role as an activating and leaving group. The bromonitroalkanes can be used in situ in a one-pot, two-step reaction to generate bis(indolyl)methanes in high yields. A wide range of 2-arylindoles is also successfully employed to create the corresponding bis(indolyl)methanes. A preliminary in vitro biological evaluation study demonstrates that these compounds possess promising α-glucosidase inhibitors (IC₅₀ = 5.45 ± 0.64–28.06 ± 0.40 μM).