Lipase‐Initiated Tandem Biginelli Reactions via in situ‐Formed Acetaldehydes in One Pot: Discovery of Single‐Ring Deep Blue Luminogens

A facile approach for the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones was developed by a tandem multi‐component reaction (MCR) in one pot. This approach involves two steps, lipase‐catalyzed in situ generation of acetaldehyde and the Biginelli reaction in turn. Several control experiments were performed using acetaldehydes directly to explore the possible mechanism of this procedure. Moreover, owing to the distinct modularity and highly efficient features of the MCR, it can assemble libraries of structurally diverse products (yields up to 98% under the optimized conditions in this paper) and provides an exceptional synthesis tool for the discovery of the minimal deep‐blue luminogen in the solid state, namely, a single ring.