Modeling of the Diels–Alder reaction enantioselectivity by quantum mechanics and molecular mechanics

The enantioselectivity of the Diels–Alder reaction between (E)-3-(4-nitrophenyl)-1-(pyridin-3-yl)prop-2-en-1-one and cyclopenta-1,3-diene in the chiral ionic liquids 3-butyl-1-methylimidazolium (S)-camphorsulfonate and (S)-1-methyl-3-(pyrrolidin-2-ylmethyl)- imidazolium tosylate or upon chiral promotion with chiral oxazaborolidine was modeled by molecular and quantum mechanics and then experimentally studied; computations were in good agreement with the experimental data, resulting in no stereoselectivity with a chiral ionic liquid used as a co-solvent and prominent stereoselectivity upon chiral promotion.