Table 1. Heteroarylation of 3 with 4.

Entry	Change from the standard conditions, reagents (equiv.)	Yield of 4a a (%)
1	Standard conditions	84 (80 b )
2	2 → Bl-OAc 1	25
3	2 → Bl-OH 5	3
4	2 → PFBl-OAc 6	30
5	2 → PhI(OTFA)27	4
6	2 → PhI(OTFA)27 (2.3), CFL → blue (LED, 100 W), HFIP → CH2Cl2, no Ru(bpy)3Cl2	3
7	2 → PhI(OAc)2	28
8	Ru(bpy)3Cl2 (0.5 → 1 mol%)	61
9	Ru(bpy)3Cl2 → Ir(ppy)3	13
10	Ru(bpy)3Cl2 → [Ir(dF(CF3)ppy)2(dtbpy)]PF6	32
11	No Ru(bpy)3Cl2	<1
12	HFIP → CH2Cl2	3
13	HFIP → CF3CH2OH	38
14	HFIP → HFIP/CH2Cl2 (1/5)	8
15	3 (1.5 → 1)	42
16	3 (1.5 → 2)	86
17	2 (1.35 → 1.5)	70
18	2 (1.35 → 1.2)	63

^aNMR yield.

^bIsolated yield on a 0.4 mmol scale.