[摘要]：Recently, a novel type of antimicrobial and proteolytically stable peptidomimetic oligomers having an a-peptide-b-peptoid chimeric backbone was reported. The present paper describes efficient protocols for the prepn. of a wide range of dimeric building blocks, displaying different types of side-chains, for use in solid-phase synthesis (SPS) of libraries of this type of oligomers. The b-peptoid monomers were obtained by microwave-assisted aza-Michael addns. to acrylic esters. Subsequent soln.-phase peptide coupling with suitably protected a-amino acids afforded dimeric intermediates. Even sluggish peptide couplings, involving sterically hindered N-alkyl-b-alanines or amino acids with bulky side-chains, gave high yields on multigram-scale when using microwave (MW) irradn. Protecting group and side-chain manipulations were performed as one-pot soln.-phase procedures to afford ten different building blocks in good to excellent yields. Finally, the efficiency of SPS oligomerization of a representative dimer was demonstrated by prepg. 10- to 16-residue homomers and by the assembly of four different building blocks to give a diversely functionalized octamer.
