Table 1.

Optimization studies.^[a]

Entry	Photocatalyst	Solvent	Light source	Yield [%][b]
1	A	DMF	24 W blue LED strips	44
2	B	DMF	24 W blue LED strips	62
3	C	DMF	24 W blue LED strips	0
4	B	DMA	24 W blue LED strips	29
5	B	DMSO	24 W blue LED strips	39
6	B	MeCN	24 W blue LED strips	5
7	B	DMF	20 W CFL	8
8	B	DMF	40 W blue LED lamp	82
9[c]	D	DMF	40 W blue LED lamp	66
10[d]	B	DMF	40 W blue LED lamp	1
11	none	DMF	40 W blue LED lamp	0
12	B	DMF	none	0

[a] All reactions were carried out with 1 (0.050 mmol), 2 (0.075 mmol), Cs₂CO₃ (0.050 mmol), the photocatalyst (0.50 μmol), and solvent (1.0 mL). [b] Determined by GC using 1,2,4‐trimethoxybenzene as an internal standard. [c] Using 5.0 mol % of the photocatalyst D. [d] Reaction performed without Cs₂CO₃. A=Ir[dF(CF₃)ppy]₂(dtbbpy)PF₆, B=Ir(ppy)₂(dtbbpy)PF₆, C=Ru(phen)₃Cl₂⋅x H₂O, D=4CzIPN. DMA=N,N‐dimethylacetamide, DMF=N,N‐dimethylformamide.