Abstract Knoevenagelcondensation of various aromatic and heteroaromatic aldehydes with active methylene compounds like methyl and ethyl cyanoacetate, malononitrile, and cyanoacetamide proceeds smoothly with stirring in water in the presence of 4 mol% of diammonium hydrogen phosphate. The reactions were carried out at room temperature in short periods with very simple workup procedure and good to high
t-butoxide catalyses the title reaction between aromatic aldehydes and malononitrile or alkyl cyanoacetates. At ambient temperatures, this procedure specifically gives high yields of E olefinic Knoevenagel products.
Synthesis of (E)-α,β-unsaturated carboxylic esters derivatives from cyanoacetic acid via promiscuous enzyme-promoted cascade esterification/Knoevenagel reaction
lipase-catalyzed cascade toward (E)-α,β-unsaturatedcarboxylic esters is presented. The proposed methodology consists of elementary organic processes starting from acetals and cyanoacetic acid leading to the formation of desired products in a cascade sequence. The combination of enzyme promiscuous abilities gives a new opportunity to synthesize complex molecules in the one-pot procedure. Results of studies
A highlyenantioselective organocatalytic domino Michael/aldol reaction is presented. The reaction is catalyzed by chiral amines and gives access to highlyfunctionalizedcyclohexanes with one all-carbon quaternary stereocenter and multiple chiral stereocenters in high yields and 83–98% ee.