Scheme 2. (A) Reactivity studies of organoboron compounds. (B) Radical trapping experiments. (C) Carbocation trapping experiments. (D) Stern–Volmer quenching. Reaction conditions: styrene 1 (0.2 mmol), RAE 2 (0.3 mmol, 1.5 equiv.), potassium organotrifluoroborate salt 3 (0.4 mmol, 2 equiv.), Ir(ppy)3 (3 mol%) in MeCN (2.0 mL, 0.1 M), 24 h irradiation with blue LEDs (λmax = 456 nm). aYield was determined by 1H NMR analysis using trimethoxybenzene as internal standard. Abbreviations: nr, no reaction.
