Optimization conditions.

Entry	Catalyst	Temperature (°C)	2-Aminopyrimidine (equiv.)	Solvent	Yielda, %
1	CuFe2O4	60	1.6	1,4-Dioxane	7
2	CuFe2O4	120	1.6	1,4-Dioxane	66
3	CuFe2O4	140	1.6	1,4-Dioxane	84, 81b
4	CuFe2O4	140	1	1,4-Dioxane	70
5	CuFe2O4	140	2.3	1,4-Dioxane	63
6	CuFe2O4	140	1.6	DMF	9
7	CuFe2O4	140	1.6	DMSO	23
8	CuFe2O4	140	1.6	Chlorobenzene	70
9c	CuFe2O4	140	1.6	1,4-Dioxane	0
10d	CuFe2O4	140	1.6	1,4-Dioxane	49
11e	CuFe2O4	140	1.6	1,4-Dioxane	15
12f	CuFe2O4	140	1.6	1,4-Dioxane	56
13	—	140	1.6	1,4-Dioxane	15
14g	CuFe2O4	140	1.6	1,4-Dioxane	24
15	CuI	140	1.6	1,4-Dioxane	38
16	CuBr2	140	1.6	1,4-Dioxane	58
17	Cu(OAc)2	140	1.6	1,4-Dioxane	34
18	FeCl2	140	1.6	1,4-Dioxane	67
19	FeCl3	140	1.6	1,4-Dioxane	41
20	Fe2O3h	140	1.6	1,4-Dioxane	21
21	CuOh	140	1.6	1,4-Dioxane	29

^a Trans-Chalcone (0.3 mmol), CuFe₂O₄ (30 μmol, 10 mol%), I₂ (0.6 mmol), solvent (2.5 mL), under O₂, 7 h. Yields are GC yields using diphenyl ether internal standard.

^bIsolated yield.

^cNo I₂.

^dI₂ (0.45 mmol).

^eI₂ (0.3 mmol).

^fCuFe₂O₄ (22.5 μmol, 7.5 mol%).

^gUnder argon.

^hNano oxides.