Table 1. Results of Rh₂(S-DOSP)₄-catalyzed carbene insertion reaction used to develop the descriptive model in Fig. 5a .

Entry a	R	R′	Toluene Substrate	Meas. 3 : 4	Meas. ΔΔG‡ (kcal mol–1)	Pred. ΔΔG‡ (kcal mol–1)
1	t-Bu	Me	4-Ethyl	20.0 : 1.0	1.92	1.90
2	CF3	Me	4-Ethyl	10.0 : 1.0	1.48	1.64
3	Br	Me	4-Isopropyl	1.9 : 1.0	0.41	0.68
4	Br	CH2CF3	4-Ethyl	11.0 : 1.0	1.54	1.50
5	t-Bu	CH2CF3	4-Isopropyl	4.5 : 1.0	0.97	0.34
6	Br	CH2CF3	4-Isopropyl	1.8 : 1.0	0.38	0.31
7	CF3	CH2CF3	4-Isopropyl	1.4 : 1.0	0.22	0.10
8	t-Bu	CH2CCl3	4-Ethyl	9.0 : 1.0	1.41	1.28
9	CF3	CH2CCl3	4-Ethyl	4.8 : 1.0	1.01	1.05
10	Br	CH2CCl3	4-Isopropyl	1.0 : 2.1	–0.48	0.07
11	Cl	Me	4-Ethyl	13.0 : 1.0	1.65	1.80
12	Br	Et	4-Ethyl	12.3 : 1.0	1.61	1.80
13	Br	CH2CBr3	4-Ethyl	5.8 : 1.0	1.13	1.15
14	OMe	Me	4-Isopropyl	4.7 : 1.0	0.99	0.73
15	OMe	CH2CCl3	4-Isopropyl	1.3 : 1.0	0.17	–0.03
16	Br	CH2CCl3	4-Ethyl	6.6 : 1.0	1.21	1.26

^aEntries 1–10, training set; entries 11–16, external validation set.