Table 1. Optimization of reaction parameters.

Entry	CF3 source	Catalyst	Additive	Yield a (%)
1	I	—	—	7
2	II	—	—	33, 21 b
3	III	—	—	12, 7 b
4	II	—	TFA (2 equiv.)	76, 62 c
5	II	—	TFA (1 equiv.)	69
6	III	—	TFA (2 equiv.)	13
7 d	II	—	TFA (2 equiv.)	59
8	II	A (5 mol%)	—	21
9	II	A (100 mol%)	B (1 equiv.)	33
10 e	II	C (5 mol%)	—	20
11 e	II	D (2 mol%)	—	31
12 e	III	C (5 mol%)	—	40
13 e	III	D (2 mol%)	—	38

^a Determined by ¹⁹F NMR integration relative to an internal standard (C₆H₅CF₃).

^b Reaction at 60 °C.

^c Reaction time is 1 h.

^d Reaction in CH₃CN.

^e 14 W bulb as light source (λ _max = 452 nm). A = Cu(CH₃CN)₄PF₆. B = 1,10-phenantroline. C = Ru(bpy)₃(PF₆)₂. D = methylene blue. TFA = trifluoroacetic acid.