Aryl fluorosulfonates set new electrophile standard for cross-couplings

Palladium-catalyzed amination in which an aryl halide or aryl triflate electrophile is coupled with an aryl or alkyl amine is one of the most popular reactions in organic chemistry. Streamlining this fundamental chemistry is hard to do, yet Patrick S. Hanley and coworkers at Dow Chemical have reported a breakthrough by developing an in situ method for generating aryl fluorosulfonates as alternative electrophiles in aminations (ACS Catal. 2016, DOI: 10.1021/acscatal.6b00865). The Dow team and other research groups previously reported using premade aryl fluorosulfonates for Suzuki couplings with aryl boronates. But the team’s one-pot amination method goes further. The researchers treated phenols with sulfuryl fluoride and a base at room temperature followed by addition of an amine coupling partner to create amination products. They found that aryl fluorosulfonates outperform other common electrophiles. In addition, the phenols can be sourced from biobased materials that are less expensive and more sustainable than petroleum-derived reagents, and the reactions can be carried out with a palladium or a nickel catalyst. The Dow researchers are now considering how to take advantage of this underexplored class of electrophile for preparing specialty chemicals, Hanley says.