Condition C: Under argon, to a solution of 4DPAIPN (2 mol%), and PNSF reagent 2a or 2b (0.1 mmol, 1.0 equiv.) in dried DCM (2.0 mL) was added corresponding heterocyclic compounds 4a-4ap, 4ar-4at (0.1 mmol) at room temperature. After that, the tube was exposed to a 90 W blue LEDs for 12 h until the reaction was completed as monitored by TLC analysis. The reaction mixture was evaporated in vacuo. The crude products were directly purified by flash chromatography on silica gel to give the desired products.