Chemoenzymatic construction of a four-component Ugi combinatorial library

The chemoenzymatic preparation of a nine-member Ugi condensation library is described. The carboxylic acid and amine precursors are based on 3-hydroxy butyrate and 4-amino-1-butanol, respectively, and have been acylated select ively using a variety of acyl donors catalyzed by porcine pancreatic lipase . The enzyme is selective for the hydroxyl functionalities on both precurso rs, thereby yielding 8-acyl-butyric acid and 4-amino-1-acyl compounds. Thes e enzymatically generated derivatives were then subjected to a four-compone nt Ugi condensation reaction in the presence of acetaldehyde and methyl iso cyanoacetate. isolated yields of the alpha-(acylamino)amide Ugi products ra nged from 72-95%. The inherent chemoselectivity of enzymatic catalysis may play an increasingly important role in expanding the structural diversity t hat can be achieved by chemical multicomponent condensation reactions. (C) 2000 John Wiley & Sons, Inc.