General synthesis of diaryliodonium tetrafluoroborates 3o-q from 1: Iodoarene 1a (1.0 equiv) and m-CPBA (1.1 equiv) were dissolved in CH2Cl2 [0.2 M] in a round bottom flask followed by addition of BF3•OEt2 (2.5 equiv). The reaction was stirred for 90 min at rt to allow oxidation of 1a. The reaction was cooled to 0 °C and boronic acid 4 (1.1 equiv) was added portionwise. The reaction was stirred at rt overnight. In situ anion exchange to triflate: Upon completion of the reaction, the flask was placed in an ice bath at 0 °C, followed by dropwise addition of TfOH (2.0 equiv). The reaction was stirred for additional 30 min at rt. The suspension was filtered through a short silica plug, eluted first with CH2Cl2 (to remove unreacted 1a) and then with CH2Cl2:MeOH to elute the product while residual boron species remained on the plug. The latter solution was concentrated and product 3 was precipitated in Et2O and isolated by filtration. If product precipitation is difficult: Stir the product in Et2O overnight at rt to achieve full precipitation.