Knoevenagel Condensation of Aldehydes and Ketones with Alkyl Nitriles Catalyzed by Strongly Basic Anion Exchange Resins under Continuous‐Flow Conditions

Abstract The use of strongly basic anion exchange resins as catalysts for Knoevenagel condensations under continuous‐flow conditions was investigated. It was found that Amberlite FPA60 was an efficient solid base catalyst for the flow synthesis of 1,2‐disubstituted alkenyl nitriles from arylmethyl nitriles and aldehydes. On the other hand, the Knoevenagel reaction involving acetonitrile required elevated reaction temperatures, which necessitated a change to a thermally robust ammonium hydroxide polymer catalyst. The potential applications of these strongly basic anion exchange resins for multi‐step continuous‐flow synthesis were also demonstrated.