Aza-Diels-Alder addition of cyclopentadiene to propynyliminoglyoxylates

► The aza-Diels-Alder reaction of cyclopentadiene with two propynyliminoglyoxylates was studied using DFT. ► There is an overall tendency for these systems to form exo cycloadducts. ► Gas phase calculations only allow the experimental evidence to be justified by thermodynamic considerations. ► Application of a solvation model selectively stabilizes the transition states located on the exo channels.