Table 1.

Optimization of the reaction conditions^a.

Entry	Solvent	NHC precatalyst	2a, (M)	Conversion (%)b	Yield (%)c
1	CH2Cl2	A	0.05	17	15
2	CHCl3	A	0.05	24	22
3	DMSO	A	0.05	20	20
4	DMF	A	0.05	43	42
5	1,4-Dioxane	A	0.05	5	5
6	Toluene	A	0.05	5	4
7	CH3CN	A	0.05	60	59
8	Ethyl acetate	A	0.05	4	4
9	CH3CN	B	0.05	43	42
10	CH3CN	C	0.05	3	3
11	CH3CN	D	0.05	7	6
12	CH3CN	E	0.05	0	0
13	CH3CN	F	0.05	3	3
14	CH3CN	G	0.05	0	0
15	CH3CN	H	0.05	2	0
16	CH3CN	A	0.07	77	77
17	CH3CN	A	0.10	86	85
18	CH3CN	A	0.17	92	88 (83)
19d	CH3CN	A	0.17	–	83
20e	CH3CN	A	0.17	0	0
21f	CH3CN	A	0.17	0	0
22g	CH3CN		0.17	0	0

^aReaction conditions: unless otherwise noted, all the reactions were carried out with benzoyl fluoride (0.4 mmol), 4-ethyl anisole (0.1 mmol), NHC catalyst (0.02 mmol), Cs₂CO₃ (0.2 mmol), and [Ir(dF(CF₃)ppy)₂(dtbbpy)]PF₆ (0.002 mmol) in anhydrous CH₃CN (2 mL), irradiation with blue LEDs at room temperature for 24 h.

^bGC-FID conversion using 1,3,5-trimethoxybenzene as an internal standard.

^c1H NMR yield using 1,3,5-trimethoxybenzene as an internal standard and yield of isolated product is given in parentheses.

^d4CzIPN (0.002 mmol) was used instead of [Ir(dF(CF₃)ppy)₂(dtbbpy)]PF₆ as the photocatalyst.

^eThe reaction was carried out in the dark.

^fNo photocatalyst was added.

^gNo NHC catalyst was added. 4CzIPN, 2,4,5,6-tetra(carbazol-9-yl)isophthalonitrile. rt, room temperature. NHC, N-heterocyclic carbene. LEDs, light-emitting diodes.