Scheme 3.

Aryl Trimethylammonium Salt Substrate Scope^a

^aReaction conditions: aryl ammonium salt 1 (0.2 mmol, 1 equiv), trialkyl phosphites 2 (0.6 mmol, 3 equiv), DBU (0.4 mmol, 2 equiv), PTZ (0.02 mmol, 10 mol %), CH₃CN/H₂O (0.75/0.25 mL), room temperature around flask is 35 °C (heating caused by the 390 nm LED lamp), air, 24 h. All yields are isolated unless noted otherwise. [a] Yields are based on 1, determined by ¹H-NMR using dibromomethane as internal standard. [b] CH₃CN/H₂O (0.25/0.75 mL) with 427 nm LED lamp.