Complex Polymer Topologies Built from Tailored Multifunctional Cyclic Polymers

Complex polymer structures, including a spiro tricyclic and first generation dendritic structures, were constructed from cyclic polymer building blocks. We described a new method to produce monocyclic polymers with hydroxyl groups equally spaced along the polymer backbone. A key synthetic feature was carrying out the CuAAC reaction of telechelic polymer chains in the presence of a bromine group through modulating the Cu­(I) activity toward the “click” reaction over radical formation. This allowed the precise control over the location of the OH groups. Azidation of the bromine groups and cyclization using a modified feed approach resulted in multifunctional monocyclics in high amounts and high purity of greater than 99% after fractionation. Conversion of the OH groups to either azide or alkyne functionality produced the central core macromolecule from which the more complex topologies were built. All four complex topologies, including a spiro tricyclic, and dendritic structures consisting of a G1 pentacyclic, G1 tertacyclic, and a G1 heptacyclic were produced in high amounts with good “click” efficiencies