Optimization of the reaction conditions for the decarboxylative radical addition to a glyoxylate-derived N-sulfinyl imine^a.

Entry	Photocatalyst	Base	Time	Yieldb	drb
1c	[Ir(dF(CF3)ppy)2(dtbbpy)](PF6), 1 mol%	Cs2CO3, 0.2 equiv.	20 min	—	—
2	[Ir(dF(CF3)ppy)2(dtbbpy)](PF6), 1 mol%	Cs2CO3, 0.2 equiv.	20 min	65%	4 : 1
3	4CzIPN, 1 mol%	Cs2CO3, 0.2 equiv.	20 min	—	—
4	[Mes-Acr-Me](BF4), 1 mol%	Cs2CO3, 0.2 equiv.	20 min	27%	>95 : 5
5	[Mes-Acr-Me](BF4), 5 mol%	Cs2CO3, 0.2 equiv.	20 min	48%	>95 : 5
			60 min	66%	>95 : 5
6	[Mes-Acr-Ph](BF4), 5 mol%	Cs2CO3, 0.2 equiv.	60 min	73%	>95 : 5
7	[Mes-Me2Acr-Ph](BF4), 5 mol%	Cs2CO3, 0.2 equiv.	60 min	78%	>95 : 5
8	[Mes-Me2Acr-Ph](BF4), 5 mol%	K3PO4, 0.2 equiv.	60 min	80%	>95 : 5
9	[Mes-Me2Acr-Ph](BF4), 5 mol%	K2CO3, 0.2 equiv.	60 min	84%	>95 : 5
10	[Mes-Me2Acr-Ph](BF4), 5 mol%	K2CO3, 0.05 equiv.	20 min	<5%	—
11	[Mes-Me2Acr-Ph](BF4), 5 mol%	K2CO3, 0.5 equiv.	60 min	85%	>95 : 5
12d	[Mes-Me2Acr-Ph](BF4), 5 mol%	K2CO3, 0.5 equiv.	60 min	77%	>95 : 5
13 e	[Mes-Me 2 Acr-Ph](BF 4 ), 5 mol%	K 2 CO 3 , 0.5 equiv.	60 min	91%	>95 : 5
14f	[Mes-Me2Acr-Ph](BF4), 5 mol%	K2CO3, 0.5 equiv.	60 min	95%	>95 : 5
15	As entry 13, but with tBu-sulfinyl imine 4		60 min	—	—
16	As entry 13, but with p-Tol-sulfinyl imine 5		60 min	50%	7 : 1
Deviations from the conditions in entry 13
17	Under air		60 min	12%	>95 : 5
18	No photocatalyst		60 min	—	—
19	No light		60 min	—	—

^aThe reactions were performed on 0.1 mmol scale: stock solutions of pivalic acid 2 and the photocatalyst (each in 1 mL of the solvent) were mixed with N-sulfinyl imine 1 and the base under anhydrous conditions, and stirred under irradiation with 440 nm blue LED light at room temperature (for details, see the ESI).

^bDetermined by ¹H NMR of crude reaction mixture with 1,3,5-trimethoxybenzene as an internal standard.

^c0.1 M DMSO.

^d0.1 M PhCF₃.

^e1.0 equiv. of N-sulfinyl imine 1 and 1.2 equiv. of pivalic acid 2.

^f1.0 equiv. of N-sulfinyl imine 1 and 1.5 equiv. of pivalic acid 2.