CAL-B catalyzed synthesis of chiral polyamides

CAL-B (Novozym 435) plays a dual role in our approach to chiral polyamides. It is used to introduce the appropriate chirality in the synthesis of monomers (amino-esters and diamines) from racemic 12-methyldodecalactone and then to catalyze their polycondensation. The AB and AABB enzymatic polymerizations have been carried out under reduced pressure; they give rise to optically active polymers in good yield, with a good degree of polymerization, and a narrow polydispersity index. This approach demonstrates that the presence of a methyl group at the stereogenic center at the α-position relative to the nitrogen atom does not slow down the polymerization as compared with the polycondensation of a related achiral monomer.