Several charge-containing TADDOL salts were synthesized and used as organocatalysts in asymmetric Diels-Alder and hetero-Diels-Alder reactions.Their catalytic activity was found to exceed that of a noncharged analog while maintaining or improving upon the enantioselectivity. The enhanced activities of the TADDOL salts enabled them to act as presumed hydrogen bond donor catalysts in the Diels-Alder and hetero-Diels-Alder reactions of 1,3-cyclohexadiene with methyl vinyl ketone at 40 C and 2-phenoxy-1,3-butadiene with ethyl glyoxylate at room temperature, respectively. Given the ionic nature of these charge-activated catalysts, it also proved possible to recycle and reuse the TADDOL without chromatography or the need for a recrystallization.
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