Reactivity and endo–exo Selectivity in Diels–Alder Reaction of o-Quinodimethanes. An Experimental and DFT Computational Study

✍ Scribed by Cristiana Di Valentin; Mauro Freccero; Mirko Sarzi-Amadè; Riccardo Zanaletti

• Book ID: 104202580
• Publisher: Elsevier Science
• Year: 2000
• Tongue: French
• Weight: 701 KB
• Volume: 56
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(00)00126-5

✦ Synopsis

endo-exo Selectivity in Diels-Alder cycloadditions of several o-quinodimethanes (1-4) with acrylonitrile, 2-(5H)-furanone and N-methylmaleimide has been investigated in acetonitrile solution. Transition structures of the cycloaddition of the parent o-QDM (1), (E,E)-1,8-dimethyl-o-QDM (2), isoindene (3) and 2,3-dihydronaphthalene (4) with acrylonitrile and maleimide were located at both HF/6-31G‫ء‬ and B3LYP/6-31G‫ء‬ methods. Theoretical data reproduce fairly well both experimental absolute reaction rates and diastereoisomer ratios. The high endo selectivity has been rationalized mainly as a result of solvation effects (acetonitrile, PCM model) and reactant deformations. The latter is due to steric interactions.