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Vittal Bhat

Vittal Bhat




University of North Carolina at Chapel Hill


Junfeng Chen

Faculty Sponsor(s): 

Craig Hawker

Faculty Sponsor's Department(s): 


Project Title: 

Preparation of Stereospecific Discrete Oligomers with Clickable Side Chains

Project Description: 

Synthetic oligomers and polymers are currently deployed in modern biological and pharmaceutical applications as polydisperse mixtures, which can lead to difficulties in the detailed evaluation of efficacy and safety in vivo. However, strategies for producing discrete-length polymers remain limited, as conventional polymerization techniques produce products with dispersity rather than single-weight species. In the Hawker lab, we have previously developed a strategy to prepare discrete oligomers from a polydisperse mixture via column chromatography. In this work, we prepared discrete, stereospecific oligomers with alkyne-containing side chains in order to develop this into a broadly bio-applicable strategy, wherein the alkyne functional handle allows the rapid creation of discrete polymer-therapeutic conjugate libraries via a Cu(I)-catalyzed azide-alkyne cycloaddition click reaction. Monomer synthesis and polymerization was performed on up to 100 gram scale, with subsequent isolation of individual oligomers proceeding efficiently on a conventional automated chromatography system. The discrete oligomers were characterized by nuclear magnetic resonance spectroscopy (NMR) and MALDI mass spectrometry. This demonstrates the ability to prepare stereospecific and discrete oligomers which can be post-functionalized into discrete oligomer libraries through simple and efficient click chemistry.