Cyclodextrin-promoted Diels Alder reactions of a polycyclic aromatic hydrocarbon under mild reaction conditions. Issue 13 (25th March 2015) - Chaudhuri, Sauradip
Graphical abstract: Abstract: Reported herein is the effect of cyclodextrins on the rates of aqueous Diels Alder reactions of 9-anthracenemethanol with a variety of N -substituted maleimides. These reactions occurred under mild reaction conditions (aqueous solvent, 40 °C) and were most efficient for the reaction of N -cyclohexylmaleimide with a methyl-β-cyclodextrin additive (94% conversion in 24 h). These results can be explained on the basis of a model wherein the cyclodextrins bind the hydrophobic substituents on the maleimides and activate the dienophile via electronic modulation of the maleimide double bond. The results reported herein represent a new mechanism for cyclodextrin-promoted Diels Alder reactions, and have significant potential applications in the development of other cyclodextrin-promoted organic transformations. Moreover, the ability to deplanarize polycyclic aromatic hydrocarbons (PAHs) under mild conditions, as demonstrated herein, has significant applications for PAH detoxification.