Table 1.

Optimization of photocatalytic trifluoromethylation of 1,1-diphenylethene 2a.^a

Entry	Photocatalyst	CF3 reagent	Solvent	Base	NMR yield (%)
1	fac-Ir(ppy)3	1a	[D6]-DMSO	K2HPO4	82
2	fac-Ir(ppy)3	1b	[D6]-DMSO	K2HPO4	17
3	fac-Ir(ppy)3	1c	[D6]-DMSO	K2HPO4	47
4	fac-Ir(ppy)3	1a	CD3CN	K2HPO4	57
5	fac-Ir(ppy)3	1a	CD2Cl2	K2HPO4	22
6	fac-Ir(ppy)3	1a	[D6]-acetone	K2HPO4	29
7	fac-Ir(ppy)3	1a	[D6]-DMSO	none	81
8	[Ru(bpy)3](PF6)2	1a	[D6]-DMSO	none	85
9	none	1a	[D6]-DMSO	none	0
10b	[Ru(bpy)3](PF6)2	1a	[D6]-DMSO	none	0

^aFor reaction conditions, see the Experimental section. ^bIn the dark.