Table 1. Optimal conditions for pyridyl radical addition to a dehydroalanine substrate ^a .

Entry	Deviation from optimal conditions	Yield of 1 b
1	None	98%
2	Without Hantzsch ester	0%
3	Without light	0%
4	Without catalyst	0%
5	Ru(bpy)3Cl2 as catalyst	58%
6	Without H2O	14%
7	DMF : H2O (5 : 1) as solvent	35%
8	EtOH : H2O (5 : 1) as solvent	71%
9	Bourbon as solvent (open to air)	93%

^aConditions: 2-bromo-5-hydroxypyridine (0.2 mmol), dehydroalanine (0.4 mmol), Ir(ppy)₂dtbbpy·PF₆ (1 mol%), Hantzsch ester (0.3 mmol), H₂O (0.33 mL), DMSO (1.66 mL), blue LED, 23 °C, 16 h.

^bYield determined by NMR.