With microwave irradiation, the submonomer synthesis of dipeptoids on functionalized cellulose can be accelerated with good yields and purity. Optimization provided a library of 96 dipeptoids. From these, 29 compounds were found with an antibacterial activity against MRSA at a concentration of 25 μM. Large nonpolar residues, such as undecylamine and dehydroabiethylamine, are the key components engendering the observed antibacterial activity of these peptoids.