Typical procedure for the hydroamination reaction: A magnetic stir bar, ynamide (1.0 equiv), pyrazole (1.2 equiv), and acridinium catalyst (Mes-Acr-MeClO4, 5.0 mol%) were added to a flame-dried 2-dram vial containing a magnetic stir bar. Dichloromethane [1.0 M] were then introduced via syringe. The vial was fitted with a septum cap and placed on a magnetic stirring plate irradiated with a blue LED lamp (456 nm) at room temperature. The course of the reaction was monitored by TLC and, upon completion, the solvent was removed and the crude reaction mixture purified by silica gel chromatography.