Iron-Catalyzed Borylation of Aryl Trifluoromethoxides

The trifluoromethoxy group, a bioisostere of the methoxy group, has emerged as a key functional group in agrochemicals and pharmaceuticals due to its high stability and lipophilicity. While extensive research exists on C(sp²)-OCF₃ bond formation, strategies for activating these bonds remain underexplored. Here, we report a highly chemoselective iron-catalyzed borylation of aryl trifluoromethoxides using a commercially available iron salt and an inexpensive ligand. Mechanistic investigations suggest a heterogeneous catalytic pathway without the formation of Grignard intermediate.