Table 2.

Optimization of the ¹⁸F‐difluoromethylation reaction.

Entry	Deviation from standard reaction conditions	RCY [18F]5 [%] (of the crude reaction mixture)
1	benzophenone[a]	47±5
2	Ru(bpy)3 (0.01 μmol)	0
3	–	70±7
4	After HPLC purification of [18F]5	42±4[b]
5	55 °C	51±10
6	30 s	60±8
7	Ir(ppy)3 (0.001 μmol)	42±2
8	DMF	44±1
9	DMSO/H2O (200/50 μL)	45±10
10	no catalyst	0
11	no light	0
12	TEMPO	0

[a] Benzophenone (10 μmol), 365 nm, [b] Radiochemical yield (n=4) of isolated product.