Primary Amine Catalyzed Biginelli Reaction for the Enantioselective Synthesis of 3,4‐Dihydropyrimidin‐2(1<i>H</i>)‐ones

Abstract

Several chiral primary amines, mainly those derived from the cinchona alkaloids, were evaluated as the organocatalysts for the asymmetric Biginelli reaction. With the quinine-derived amine catalyst 1 and after extensive optimization of the reaction conditions, 3,4-dihydropyrimidin-2(1H)-ones were obtained in moderate to good yields and 51-78% ee from a three-component reaction of aryl and aliphatic aldehydes, urea, and acetoacetate.