Table 1.

Optimization of copper-catalyzed photoredox Chan-Lam coupling of 1a with 2a.

Entry	catalyst/mol %	Solvent	Conc./M	Assay yielda/%
1	Cu(OAc)2.H2O/20	MeOH	0.3	25
2	CuCl/20	MeOH	0.3	5
3	CuF2/20	MeOH	0.3	30
4	Cu(O2CCF3)2.H2O/20	MeOH	0.3	36
5	Cu(O2CCF3)2.H2O/20	EtOH	0.3	90
6	Cu(O2CCF3)2.H2O/20	iPrOH	0.3	49
7	Cu(O2CCF3)2.H2O/20	tBuOH	0.3	0
8	Cu(O2CCF3)2.H2O/10	EtOH	0.3	90
9	Cu(O2CCF3)2.H2O/5	EtOH	0.3	45
10b	Cu(O2CCF3)2.H2O/10	EtOH	0.3	90
11c	Cu(O2CCF3)2.H2O/10	EtOH	0.3	75
12b	Cu(O2CCF3)2.H2O/10	EtOH	1.5	95(94d)
13b	Cu(O2CCF3)2.H2O/10	EtOH	2.0	85
14b	-	EtOH	1.5	0
15e	Cu(O2CCF3)2.H2O/10	EtOH	1.5	17(20f)
16 g	Cu(O2CCF3)2.H2O/10	EtOH	1.5	66

General conditions: unless otherwise stated, reactions were carried out with 1a (0.3 mmol) and 2a (2.3 equiv) at room temperature under argon for 48 h.

^aAssay yields determined by ¹H NMR using 0.1 mmol CH₂Br₂ (7.0 μL) as internal standard.

^b2a (2.0 equiv).

^c2a (1.5 equiv).

^dIsolated yield.

^ePhenyl boronic acid pinacol ester employed.

^fB(OH)₃ (3.0 equiv) as an additive.

^gPotassium phenyl trifluoroborate (3.0 equiv) employed for 72 h.