Optimization of reaction conditions^a.

Entry	Conditions	Yield (%)
1	As shown	83 (76b/73c)
2	No photocatalyst	N.D.
3	No light	N.D.
4	No NiCl2·glyme	N.D.
5	No DBU	10
6	No LiCl	54
7	With TEMPO (3.0 equiv.)	N.D.
8	ArCl instead of ArBr	76
9	ArI instead of ArBr	16
10d	ArOTf instead of ArBr	36

^aReaction conditions: 1a (0.15 mmol), 2a (0.10 mmol), [Ir] (1.0 mol%), NiCl₂·glyme (5.0 mol%), L (7.5 mol%), DBU (0.10 mmol), LiCl (0.15 mmol), and DMA (0.050 M) irradiated with 34 W blue LEDs. Yields were determined by ¹H NMR analysis using 1,1,2,2-tetrachloroethane as an internal standard.

^bThe reaction was set up using standard Schlenk technique on the benchtop.

^cThe reaction was carried out under ambient conditions.

^dWithout LiCl. [Ir] = Ir(dFCF₃ppy)₂(dtbbpy)PF₆. dtbbpy = 4,4′-di-tert-butyl-2,2′-bipyridine. L = 1,10-phenanthroline. DMA = N,N-dimethylacetamide. TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxyl. N.D. = not detected.