Use of Protease from <i>Bacillus licheniformis</i> as Promiscuous Catalyst for Organic Synthesis: Applications in CC and CN Bond Formation Reactions

Abstract

Abstract Commercially available protease from Bacillus licheniformis has been used in different non‐conventional biotransformations showing remarkable activity values. The promiscuous behaviour of this enzyme used in the cross‐linked enzyme aggregates immobilized form (Alcalase‐CLEA ® ), has been successfully demonstrated for the first time in CC bond formation processes such as aldol, Henry and Mannich reactions. On the other hand, the Bayllis–Hillman reaction between 4‐nitrobenzaldehyde and methyl vinyl ketone occurred through unspecific catalysis. Interestingly, aza‐ Michael addition reactions of secondary amines (diethylamine, piperidine and pyrrolidine) to acrylonitrile have been also efficiently catalyzed, observing with diethylamine the most remarkable differences between the enzyme‐mediated reaction and the one in the absence of catalyst. Higher reactivities were attained with pyrrolidine demonstrating the versatility of hydrolases in organic synthesis.