Table 1.

Optimization of the reaction conditiosn.

Entry	TfX	Base	Chloride source	2 a [a] [%]	1 a [a] [%]	Other[a] [%]
1	Tf2O	2‐I‐pyr	–	71	22	8
2	Tf2O	pyridine	–	51	40	9
3	Tf2O	2‐I‐pyr	TEAC[b]	89	11	0
4	TfCl	2‐I‐pyr	–	nd[c]	100	0
5[d]	Tf2O	2‐I‐pyr	TEAC[b]	100	nd[c]	0

[a] Yields determined by ³¹P NMR analysis of the crude residue. [b] Tetraethylammonium chloride. [c] Not detected. [d] With fully optimized conditions: 2‐Iodopyridine (1.5 equiv) and triflic anhydride (2 equiv) were added to a solution of the phosphonate (0.2 mmol) in CH₂Cl₂ (4 mL) at 0 °C. After 30 min, TEAC (2.5 equiv.) was added at 0 °C. After another 15 min, a solution of the deprotonated nucleophile (4 equiv) in THF (2 mL) was added, and the reaction mixture was stirred at room temperature for 18 h. 2‐I‐pyr=2‐iodopyridine.