. Author manuscript; available in PMC: 2010 Feb 11.

Published in final edited form as: J Am Chem Soc. 2009 Feb 11;131(5):1947–1957. doi: 10.1021/ja8079548

Table 4.

Activation Barriers and Their Dissection into Distortion and Interaction Energies for Endo and Exo TSs of 1d and 1e+A₂ (kcal/mol).

Entries	Reactants	Method		ΔE^‡	ΔE_d^‡		ΔE_i^‡
Entries	Reactants	Method		ΔE^‡	diene	dienophile complex A₂	ΔE_i^‡
1	1d+A₂	B3LYP/6−31G(d)	endo	2.0	10.9	14.2	−23.2
2		B3LYP/6−31G(d)	exo	−0.1	9.2	12.7	−22.0
3		MP2/6−31+G(d)	endo	−14.8	10.0	14.3	−39.1
4		MP2/6−31+G(d)	exo	−14.1	8.4	12.7	−35.2
5	1e+A₂	B3LYP/6−31G(d)	endo	−1.4	6.0	7.6	−15.0
6		B3LYP/6−31G(d)	exo	−1.3	6.3	8.2	−15.8
7		MP2/6−31+G(d)	endo	−12.9	5.9	7.6	−26.3
8		MP2/6−31+G(d)	exo	−11.2	6.1	8.2	−25.4