Enantioselective Benzoin Condensations

Benzoin-condensations are long studied Reactions, these reactions require the conversion of an aldehyde Carbon from an electrophile to a nucleophile in a process called umpolung. It was shown that boronic acids could serve as in-situ directing groups to control the enantioselectvity of organocatalytic reactions. In this work, Boronic acids are used to modify the reaction intermediates, the N-Heterocyclic carbene catalyst and aryl aldehydes -in situ- and optimize the selectivity and reactivity of the reaction.