Table 1.

Characteristics of σ‐hole catalysts.

Entry	Catalyst[a]	Element[b]	K D	E int	η [%]		k cat/k uncat		ΔE a [kJ mol−1]
			[μm][c]	[kcal mol−1][d]	15 [e]	18 [f]	15 [g]	18 [h]	15 [i]	18 [j]
1	1	Sb	19±7	−51.8	53	91	4090	99	−20.3	−11.2
2	8	Sb	570±70	−44.4	40	30	209	14	−13.0	−6.5
3	9	Sb	n.d.[k]	−37.2	3	11	–	–	–	–
4	10	Sb	n.d.[l]	−22.6	3	8	–	–	–	–
5	4	Te	470±70	−39.7	47	48	52	39	−9.6	−8.9
6	6	I	1370±30	−27.8	47	15	50	5	−9.5	−4.1
7	2	As	13300±800	−40.8	3	7	–	–	–	–
8	5	Se	27000±4000	−28.5	6	6	–	–	–	–
9	7	Br	n.d.[k]	−17.7	4	6	–	–	–	–
10	3	P	n.d.[k]	−30.0	3	n.d.	–	–	–	–

[a] Catalyst candidates; structures shown in Figure 2. [b] Central atom of the catalyst, engaged in σ‐hole interactions. [c] Dissociation constant determined by ¹⁹F NMR titration with TBACl in THF. [d] Chloride binding energy in the gas phase calculated at the M06‐2X/6–311G**/aug‐cc‐pVTZ‐pp level of theory. [e] Yield of product 15 determined after 4–6 h by ¹H NMR integration (see Scheme 1). [f] Yield of 18, determined after 55 h. [g] Rate enhancement for the formation of 15, compared to k _uncat=110 mm ⁻¹ h⁻¹. [h] Rate enhancement for the formation of 18, compared to k _uncat=168 mm ⁻¹ h⁻¹. [i] Change in the activation energy for the formation of 15, compared to k _uncat=110 mm ⁻¹ h⁻¹, from k _cat/k _uncat. [j] Change in the activation energy for the formation of 18, compared to k _uncat=168 mm ⁻¹ h⁻¹, from k _cat/k _uncat. [k] No saturation was observed; see Figure S7. [l] Not determined owing to the lack of fluorine substituents.