Table 3.

Eyring parameters for cycloadditions of nitroethene (1) to the N-oxides 2a, 2d, and 2h according to DFT (PCM) calculations (∆H, ∆G are in kcal/mol; ∆S is in cal/mol K)

Solvent	Level of theory	Reaction	Transition	∆H	∆S	∆G
Toluene	B3LYP/6-31G(d)	1 + 2a	1 + 2a → MC	−3.1	−29.1	5.6
			1 + 2a → TS A	10.7	−47.9	25.0
			1 + 2a → 3a	−34.0	−50.5	−19.0
			1 + 2a → TS B	11.3	−43.6	24.3
			1 + 2a → 4a	−38.7	−50.3	−23.7
	B3LYP/6-31G(d	1 + 2d	1 + 2d → MC	−3.0	−23.6	4.0
			1 + 2d → TS A	12.9	−43.3	25.8
			1 + 2d → 3d	−34.1	−48.7	−19.6
			1 + 2d → TS B	12.1	−41.9	24.6
			1 + 2d → 4d	−38.5	−47.8	−24.3
	B3LYP/6-31 + G(d)	1 + 2d	1 + 2d → MC	−1.4	−25.4	6.1
			1 + 2d → TS A	14.8	−42.9	27.6
			1 + 2d → 3d	−30.4	−47.5	−16.3
			1 + 2d → TS B	14.2	−42.7	26.9
			1 + 2d → 4d	−35.2	−46.1	−21.4
	B3LYP/6-311G(d)	1 + 2d	1 + 2d → MC	−3.0	−28.6	5.5
			1 + 2d → TS A	14.6	−44.3	27.8
			1 + 2d → 3d	−29.2	−48.3	−14.8
			1 + 2d → TS B	14.0	−41.7	26.5
			1 + 2d → 4d	−33.8	−47.4	−19.7
	B3LYP/6-31G(d)	1 + 2h	1 + 2h → MC	−3.4	−29.3	5.4
			1 + 2h → TS A	13.1	−45.1	26.6
			1 + 2h → 3 h	−34.8	−48.5	−20.3
			1 + 2h → TS B	12.4	−43.9	25.5
			1 + 2h → 4 h	−38.8	−48.3	−24.3
Water	B3LYP/6-31G(d	1 + 2d	1 + 2d → MC	−1.5	−26.6	6.4
			1 + 2d → TS A	13.6	−43.4	26.5
			1 + 2d → 3d	−33.5	−48.2	−19.1
			1 + 2d → TS B	12.3	−41.8	24.8
			1 + 2d → 4d	−38.5	−47.3	−24.5