Atom Transfer Radical Polymerization of Adenine, Thymine, Cytosine, and Guanine Nucleobase Monomers

Methacrylate monomers functionalized with thymine, adenine, cytosine, and guanine were prepared by alkylation of the nucleobases with 3-bromopropyl methacrylate. Application of atom transfer radical polymerization in deuterated DMSO allowed controlled polymerization of the adenine-, thymine-, and for the first time, also of the cytosine- and guanine-modified monomers. The guanine and cytosine monomers appeared to form a complex with the copper catalyst, as could be observed with 1H NMR spectroscopy. In the case of guanine, this did not cause any problems for the polymerization process, while in the case of cytosine, a stronger copper binding ligand, PMDETA, needed to be applied to gain control over polymerization.