Quantum-chemically calculated energy profiles (in kJ mol⁻¹) for the addition of the sulfonium ylide 7 to the electrophiles 1–5 at the SMD(DMSO)/M06-2X/6-31+G(d,p) level of theory.

Electrophiles	Mayr E	k 2 (M−1 s−1)	ΔG‡expb	Trans-pathway				Cis-pathway
				ΔG‡(TS1)c	ΔG°(IM)	ΔG‡(TS2)	ΔG°	ΔG‡(TS1)c	ΔG°(IM)	ΔG‡(TS2)	ΔG°
1a	−20.6	1.1	71.5	73.5	15.3	35.8	−160.0	81.6	16.3	47.9	−152.7
1b	−22.1	1.1	71.6	83.7	28.8	51.1	−150.9	82.1	34.9	61.2	−144.3
1c	(−28.9)	4.7 × 10−6 a	101.7	101.1	46.7	66.8	−140.5	101.5	41.9	70.7	−137.7
2a	−22.1	0.52	73.4	82.4	19.2	42.9	−161.4	82.9	18.8	62.2	−145.0
2b	(−27.5)	4.1 × 10−5 a	96.4	92.4	42.9	54.8	−151.3	88.5	39.4	74.6	−139.7
2c	(−29.6)	1.6 × 10−6 a	104.3	103.4	46.3	70.0	−143.9	102.1	48.7	83.1	−133.1
3	−22.0	0.53	73.3	80.7	19.0	45.5	−172.8	85.8	12.4	56.7	−151.7
4a	−20.7	2.9	69.2	72.8	20.3	40.1	−159.5	79.9	17.7	56.8	−156.9
4b	−19.4	8.4	66.6	73.8	−1.0	24.8	−179.7	Ident.	Ident.	25.8	−179.3
5a	−21.8	0.41	73.9	78.3	15.0	44.3	−165.6	79.5	17.6	57.2	−153.3
5b	−19.5	5.1	67.8	68.6	−5.0	15.4	−176.0	Ident.	Ident.	24.0	−181.9

^a k ₂ calculated by using eqn (1), the nucleophilicity parameters N and s_N of 7 and the electrophilicity parameters E from Table 1.

^bCalculated by applying k₂ in the Eyring equation.

^cEntries for ΔG^‡(TS1) printed in bold indicate the favored transition state (trans vs. cis) used for the correlations in Fig. 5.