Table 1. Optimization of Reaction Conditions in Nickel(0)-Catalyzed C(aroyl)–F Bond Ethylation of Biphenyl-4-Carbonyl Fluoride (1a) with BEt₃ (2a)^a.

			yield (%)b
entry	ligand	base	3aa	4aa
1	PPh3	none	0	21
2	PCy3	none	22	26
3c	DPPE	none	0	83 (78)
4c	DPPBz	none	0	45
5	ICy·HCl	pyridine	27	trace
6c,d	DPPE	none	0	85 (85)
7c,e	DPPE	none	0	77 (73)
8c,f	DPPE	none	0	28
9	none	none	0	0

^aReaction conditions: 1a (0.125 mmol, 1.0 equiv), 2a (0.125 mmol, 1.0 equiv), Ni(cod)₂ (0.0125 mmol, 10 mol %), ligand (0.025 mmol, 20 mol %), base (0.025 mmol, 20 mol %), solvent (0.5 mL, 0.25 M of 1a), 120 °C, 24 h.

^bDetermined by ¹H NMR analysis of the crude mixture, using dibromomethane as an internal standard. An isolated yield was shown in parentheses.

^c10 mol % of ligand was used.

^dAt 130 °C for 24 h.

^eAt 140 °C for 24 h.

^fAt 110 °C for 24 h. DPPE, 1,2-bis(diphenylphosphino)ethane; DPPBz, 1,2-bis(diphenylphosphino)benzene; ICy·HCl, 1,3-dicyclohexylimidazolium chloride; Ni(cod)₂, bis(1,5-cyclooctadiene)nickel(0); PCy₃, tricyclohexylphosphine.