Reversal of electronic Substituent Effects in the Retro-Diels-Alder Reaction. A Charge Neutral Analogue of Oxyanion-Accelerated Cycloreversion

Article abstract of DOI:10.1021/jo00364a056

The retro-Diels-Alder reaction of anthracene cycloadducts is influenced by the dienophile substituents in the following ways: (1) electron-withdrawing groups increase the rate of the reaction; (2) strongly conjugating substituents make the reaction much faster than predicted by classical electron-withdrawing or -donating ability, in the best case by a factor of 3 x 10⁶, and (3) there is no observable steric effect, in contrast to literature statements to the contrary.