Halogen Bond‐Catalyzed Friedel−Crafts Reactions of Furans Using a 2,2’‐Bipyridine‐Based Catalyst

A halogen bond donor based on a 2,2’‐bipyridine framework has been synthesized, and used to catalyze Friedel−Crafts reactions of furans. Electrophiles used successfully in these reactions included various enones, an aldehyde, and a carboxylic acid anhydride. The yields of the reactions were generally good using a moderate catalyst loading (0.025 or 0.1 equiv.) at a relatively low temperature (room temp. or 50 °C) in acetonitrile. The catalyst used was designed with a biaryl scaffold so that if it indeed proved to be an efficient halogen bond donor organocatalyst, an enantioenriched version of it could potentially serve as a stereoselective catalyst.