Catalytical promiscuity of α-amylase: Synthesis of 3-substituted 2H-chromene derivatives via biocatalytic domino oxa-Michael/aldol condensations

An facile and green one-pot route has been developed for the synthesis of chromenes using salicylaldehyde and α,β-unsaturated ketones. α-Amylase from Bacillus subtilis shows excellent catalytic activity and exerts good adaptability to different substrates in the reaction. This promiscuous enzyme-catalyzed domino reaction not only extends the application of α-amylase from B. subtilis for new chemical transformations, but also provided an alternative synthetic method for 2H-chromene derivatives.