Natural α-Amino Acid L-Lysine–Catalyzed Knoevenagel Condensations of α,β-Unsaturated Aldehydes and 1,3-Dicarbonyl Compounds

Abstract

Knoevenagel condensations of α,β-unsaturated aldehydes and 1,3-dicarbonyl compounds were catalyzed by primary natural amino acid L-lysine. The reactions were carried out at room temperature in dimethylsulfoxide. It provides a facile entry to a wide variety of α,β,γ,δ-unsaturated dicarbonyl compounds.

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Keywords:

• 1,3-Dicarbonyl compound
• Knoevenagel condensation
• L-lysine
• α,β-unsaturated aldehyde

ACKNOWLEDGMENT

Financial support from the Natural Science Foundation Project of CQ CSTC (CSTC, 2009BA5051) is gratefully acknowledged.

Notes

^a Refers to yield of isolated product after flash chromatography.

^a Refers to yield of isolated product after flash chromatography.

^a Refers to yield of isolated product after flash chromatography.

^a Refers to yield of isolated product after flash chromatography.

^b Refers to the total yield of two isomers. The ratio of two isomers: Z/E = 2.1 for entries 2 and 8; Z/E = 2.2 for entries 13 and 18; Z/E = 3.2 for entry 24. Z and E refer to the newly formed double bond between α-C and β-C.