A Practical Synthesis of 2‐Arylimino‐2H‐Chromenes via Biocatalytic System in Water

Abstract A metal‐free, straightforward, non‐hazardous reagent‐added, one‐pot approach for the efficient synthesis of 2‐arylimino‐2 H ‐chromenes with high yields was developed for the first time in this report through the coupling of salicylaldehydes with β‐ketothioamides, which was catalyzed by lipase in water. This green strategy provides an efficient method to obtain various 2‐arylimino‐2 H ‐chromenes and enriches the practical application of biocatalysis.