Saccharides, based on their wide bioavailability, high chemical functionality and stereochemical diversity, are attractive starting materials for the development of new synthetic polymers. Established carbonylation methodologies were used to synthesize a 5-membered cyclic carbonate monomer, 4,6-O-benzylidene-2,3-O-carbonyl-α-d-glucopyranoside (MBGC), in high yield (>95%) from a commercially available d-glucopyranoside derivative. The ability of this monomer to undergo ring-opening polymerization (ROP) with a range of organocatalysts, rather than the previously reported anionic initiators, was investigated. These new conditions were developed to widen the functional group tolerance in the polymerization, and achieve better control over the final properties of the polymers. The most promising of the catalysts examined, 1,5,7-triazabicyclo[4.4.0]­dec-5-ene (TBD), was used in a kinetic study to confirm the well-controlled nature of the ROP. Optimized conditions were then successfully applied to the synthesis of polymers of different molecular weights. Two post-polymerization modifications were completed via the removal of the benzylidene acetal protecting group to release a water-soluble poly­(glucose carbonate), and then addition of acetyl groups to facilitate characterization studies. MALDI-TOF MS analysis was performed to further probe the chemistry of the polymerization and deprotection. A wide range of thermal decomposition temperatures (233–347 °C), glass transition temperatures (87–233 °C), and water contact angles (38–128°) was achieved by this series of polymers. The hydrolytic degradability of these polymers was also examined, demonstrating differing degradation mechanisms based on the acidic vs. basic conditions used. Consequently, this single monomer was successfully employed in the straightforward synthesis of a polymeric system with tunable properties based on the molecular weight and repeat unit composition.

Ferulic acid (FA), a bio-based resource found in fruits and vegetables, was coupled with a hydroxyl-amino acid to generate a new class of monomers to afford poly(carbonate–amide)s with potential to degrade into natural products. l-Serine was first selected as the hydroxyl-amino partner for FA, from which the activated p-nitrophenyl carbonate monomer was synthesized. Unfortunately, polymerizations were unsuccessful, and the elimination product was systematically obtained. To avoid elimination, we revised our strategy and used l-tyrosine ethyl ester, which lacks an acidic proton on the α position of the ethyl ester. Four new monomers were synthesized and converted into the corresponding poly(carbonate–amide)s with specific regioselectivities. The polymers were fully characterized through thermal and spectroscopic analyses. Preliminary fluorescent studies revealed interesting photophysical properties for the monomers and their corresponding poly(carbonate–amide)s, beyond the fluorescence characteristics of l-tyrosine and FA, making these materials potentially viable for sensing and/or imaging applications, in addition to their attractiveness as engineering materials derived from renewable resources.

A series of hydrolytically degradable fluorescent poly(ferulic acid-co-tyrosine)-g-mPEG graft copolymers were synthesized and shown to undergo self-assembly in aqueous media to yield fluorescent micelles. The polymers and their micellar assemblies exhibited greater fluorescence emission intensity than did their small molecular building blocks, which provides a self-reporting character that has potential for monitoring the polymer integrity and also for performing in theranostics applications. The amphiphilic graft-copolymers were synthesized by Cu-assisted azide–alkyne “click” addition of azido-functionalized mPEG polymers onto fluorescent degradable hydrophobic copolymers displaying randomly distributed alkyne side-chain groups along their biorenewably derived poly(ferulic acid-co-tyrosine) backbones. The morphologies and photophysical properties of the supramolecular assemblies generated in aqueous solutions were evaluated by DLS, TEM, AFM, and steady-state optical spectroscopies. The 15–30 nm sized micelles behaved as broad-band emitters in the 350–600 nm range, which highlights their potential as self-reporting nanomaterials for in vitro studies.

N-acetyl 4-O,5-N-oxazolidinone protected sialyl phosphates of either anomeric configuration are excellent donors for the formation of α-S-sialosides at -78 °C in dichloromethane with primary, secondary, and tertiary thiols including galactose 3-, 4-, and 6-thiols. The reactions, which proceed under typical Lewis acid promoted glycosylation conditions, are highly α-selective and do not suffer from competing elimination of the phosphate.