Abstract
A chiral ionic liquid, 1-butyl-3-methylimidazolium (T-4)-bis[(2S)-2-(hydroxy-κO) propanoato-κO]borate (BMIm+BLLB-), has been used as organocatalyst and asymmetric inducer in Diels-Alder reactions between anthrone and various maleimides. This greener solvent makes the reaction faster, proceeds with quantitative yields and exhibits moderate enantioselectivity. Stereochemical outcome suggests a more organized transition state in ionic liquid involving hydrogen bonding and polar interactions.
Keywords: Chiral ionic liquid, diels-alder reaction, bronsted base, green solvents, enantioselective, HPLC