Acceleration of Multicomponent Reactions in Aqueous Medium: Multicomponent Synthesis of a 4H-pyran Library

Abstract

A combinatorial library of 2-amino-4H-pyran derivatives has been developed by a threecomponent reaction between aldehyde, malononitrile and β-dicarbonyl compounds (ethyl acetoacetate or acetylacetone) in the presence of ammonium acetate in aqueous medium. This protocol couples the benefits of multi-component reaction (MCR) with those of water as solvent for organic transformations, thus facilitating efficient chemical production in an environmentally benign way.

Triethylamine — A Versatile Organocatalyst in Organic Transformations: A Decade Update

“…tivities such as anticancer 96 neurodegenerative, antimicrobial, antifungal, 97 antiviral, [98][99][100][101] antioxidant, 102 and anti-inflammatory. 103 This method is an alternative to several other similar methods [104][105][106][107][108] implementing the synthesis of polyfunctionalized 4-(4H-pyran-4-yl)-2H-chromen-2-ones 41 from the stepwise reaction between 4-formylcoumarin 38, malononitrile (31), and ethyl acetoacetate (40) in aqueous ethanol at room temperature using triethylamine as a catalyst (Scheme 13). High yields, shorter reaction time, avoidance of chromatographic purification, and mild reaction conditions are some of the notable features of this process.…”