Optimisation of the reaction conditions^a.

Entry	Copper salt 10%	Ligand 10%	Solvent	Yieldb,c[%]
1	Cu(MeCN)4BF4	Neocuproine	DCE	(48)
2	—	Neocuproine	DCE	—
3	Cu(BF4)2·H2O	Neocuproine	DCE	53(54)
4	Cu(BF 4 ) 2 ·H 2 O	Neocuproine	MeNO 2	74(75)
5	Cu(BF4)2·H2O	Neocuproine	CH3CN	(45)
6	Cu(BF4)2·H2O	Neocuproine	Toluene	(53)
7	Cu(BF4)2·H2O	Neocuproine	Ph-Cl	(66)
8	Cu(BF4)2·H2O	Neocuproine	EtOAc	(27)
9	Cu(BF4)2·H2O	Neocuproine	MeOH	(66)
10	Cu(BF4)2·H2O	2,2′-Bipyridine	MeNO2	(57)
11	Cu(BF4)2·H2O	1,10-Phenanthroline	MeNO2	(39)
12d	Cu(BF4)2·H2O	Neocuproine	MeNO2	(36)
13e	Cu(BF4)2·H2O	Neocuproine	MeNO2	(72)
15f	Cu(BF4)2·H2O	Neocuproine	MeNO2	(73)
16g	Cu(BF4)2·H2O	Neocuproine	MeNO2	(69)
17h	Cu(BF4)2·H2O	Neocuproine	MeNO2	(57)
18i	Cu(BF4)2·H2O	Neocuproine	MeNO2	(36)

^aReactions were carried out with 1a (1.0 mmol) in 3.0 mL of solvent, Ph-I N-Ts (1.5 eq.), MeOH (10 eq.), Mo(CO)₆ (0.25 eq) in an open tube, unless otherwise noted.

^bNMR-determined yields in a 0.20 mmol scale reaction of 1a using 1,3,5-trimethoxybenzene as internal standard are shown in parentheses.

^cIsolated yields.

^dCatalyst 5%.

^e30 min.

^fMeOH (5.0 eq.).

^gMeOH (2.0 eq).

^hMo(CO)₆ (0.1 eq.).

ⁱNeocuproine (20%).