The DAP-OBn was synthesized according to the procedure reported by our group. [1] In a flame-dried Schlenk flask in the glovebox, a solution of phenylmethanol (167 µL, 1.61 mmol, 1.5 equiv.) and trimethylamine (268 µL, 1.93 mmol, 1.8 equiv.) in THF (1.08 mL) was added dropwise at room temperature to a suspension of 2-halo-1,3,2-diazaphospholene (0.30 g, 1.075 mmol, 1.0 equiv.) in THF (4.3 mL). The mixture was stirred at room temperature for 1h before being evaporated to dryness. The resulting solid was then suspended in toluene and filtered through celite before being dried under vacuum again. Finally, recrystallization of the obtained solid from acetonitrile to obtain white crystal compound.