Table 1.

Selected examples of the optimization of the fluoride‐promoted preparation of polyfluorinated biaryls.^[a]

Entry	Catalyst	Solvent	Time	Yield [%][b]
				3 aa 5a	6
1	CsF/18‐C‐6[c]	THF	2 h	77	15
2	CsF	THF	48 h	91	5
3	CsF	DMF	<5 min	92 (79)[d]	7
4[e]	KF	DMF	24 h	57	5
5[e]	NaF	DMF	24 h	trace	trace
6[e]	LiF	DMF	24 h	trace	trace
7	TBAT	DMF	<5 min	89	7
8	TMAF	DMF	<5 min	62	16
9[e]	KOSiMe3	DMF	24 h	30	3
10[e]	none	DMF	24 h	0	0

[a] All reactions were performed on a 0.10 mmol scale in 0.7 mL (0.1 M) of the indicated solvent. [b] Determined by calibrated GLC analysis with tetracosane as an internal standard. [c] CsF/18‐crown‐6 (1.0 : 1.2 molar ratio). [d] Yield of isolated product on a 0.30 mmol scale after flash chromatography on silica gel in parentheses. [e] Incomplete conversion of 1 a. TBAT=tetrabutylammonium difluorotriphenylsilicate, TMAF=tetramethylammonium fluoride.