engleski

High-level Computational Study of the Site-, Facial- and Stereoselectivities for the Diels-Alder reaction between o-benzoquinone and Norbornadiene

Ab initio and DFT quantum chemical calculations have been applied to a study of the Diels-Alder reaction of o-benzoquinone as diene and norbornadiene as dienophile. Transition states for the different reactions are located and activation energies estimated. The prefered exo--facial selectivity and exo,endo-stereoselectivity exhibited in this cycloaddition are readily predicted using RHF/3-21G or higher levels of calculations. Differences between experimentally observed results and calculations may be explained by the postulation of a second, nonconcerted biradical mechanism leading to formation of hetero Diels-Alder products.

cycloaddition; inverse electron-demand; o-benzoquinones; ab initio; DFT calculations

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