Method 3: A 10 mL Schlenk flask equipped with a stir bar was charged with 1 (40 mg, 0.020 mmol, 1 equiv) and C6H6 (10 mL). The flask was degassed (freeze, pump, thaw, 3 cycles) and placed under a dry O2 atmosphere. The mixture was stirred at room temperature for 12 hours, resulting in a dark red solution. All volatiles were removed under reduced pressure. The red residue was repeatedly washed with pentane, followed by diethyl ether. The remaining solid was extracted with toluene and filtered through a pad of Celite. All volatiles were removed from