Table 1. Experiments for the Hydrodefluorination of 4-(Trifluoromethyl)benzonitrile 1a.

Entry	Alterations to conditions	Yielda(ratio 1b:1c)
1	Mg0 (30 equiv), H2O/AcOH/DMSO	0%
2	Pd(OAc)2 (3 mol %), CuF2 (20 mol %), 2-pyridone (5 mol %), KOSiMe3 (7.0 equiv), DMF, 45 °C, then tBuOH (2.0 equiv), 60 °C	0%
3b	Miyake Phenoxazine (2 mol %), II (3 equiv), blue LED, DMSO, 50 °C, 24 h	4% (2:1)
4c	fac-Ir(ppy)3 (1.0 mol %), TMP (2.0 equiv), HBPin (3.0 equiv), blue LED, DCE, rt, 24 h	0%
5d	PTH (10 mol %), VI (10 mol %), II (3 equiv), blue LED, 5% H2O/DMSO, rt, 24 h	0%
6	fac-Ir(ppy)3 (2.5 mol %)	53% (5:1)
7	4-DPA-IPN (2.5 mol %)	62% (5:1)
8	No alteration	65% (5:1)
9	I (6 equiv) instead of III	trace
10	II (6 equiv) instead of III	trace
11	IV (6 equiv) instead of III	0%
12	V (6 equiv) instead of III	15% (5:1)
13	VI (6 equiv) instead of III	4% (8:1)
14	VII (6 equiv) instead of III	4% (8:1)
15	VIII (6 equiv) instead of III	5% (8:1)
16	IX (6 equiv) instead of III	22% (7:1)
17	X (6 equiv) instead of III	22% (7:1)
18	no PMP	51% (5:1)
19	no TMP	31% (>20:1)
20	no TMP and no PMP	0%
21	no light	0%
22	no 4-HTP	0%
23	no photocatalyst	0%

^aCombined yields of 1b and 1c determined by ¹⁹F NMR using 4-fluoroanisole as internal standard; the ratio of 1b:1c is given in parentheses.

^bReaction carried out on 14a.

^cConditions of ref (7c) with no alkene.

^dConditions of ref (7b) with no alkene. PTH = 10-phenyl-10H-phenothiazine. BDE values for arylthiols from ref (9).