The effect of the amount of copper salts for the one-pot synthesis of 6a.

Entry	Catalyst	mol%	Time (h)	Isolated yield (%)
1	Cu(OAc)2·H2O	10	17	90
2	Cu(OAc)2·H2O	15	16	95
3	Cu(OAc)2·H2O	20	16	95
4	CuSO4·5H2O + Na ascorbate	10	18	81
5	CuSO4·5H2O + Na ascorbate	15	17	87
6	CuI	10	18	50
7	CuI	15	17	61
8	CuCl	10	17	40
9	CuCl	15	17	45