Table 2.

Optimization of glycosyl cross-coupling.^[a]

Entry	Cu	Fluoride	Se	T [°C]	t [h]	Yield [%][b,c]
1	CuCI	KF	A	110	24	91
2	CuCI	None	A	110	24	70
3	None	KF	A	110	24	< 5
4d	CuCI	KF	A	110	24	69
5	CuCl	KF	A	110	12	74
6	CuCl	KF	A	90	24	55
7	CuCl	KF	B	110	24	79
8	CuCl	KF	C	110	48	88
9	CuCl	KF	D	110	24	44
10	CuCl	KF	E	110	24	62

^[a]Reaction conditions: selenide A–E (0.100 mmol, 1.0 equiv), 14 (1.1 equiv), fluoride (2 equiv), CuX (1.5 equiv), and dry 1,4-dioxane (2 mL) under N₂, 110°C;

^[b]isolated yield;

^[c]only β-anomer formed;

^[d]1 equiv of CuCl.