Architectural Editing of Polyesters and Polyurethanes via Palladium(II)-Catalyzed [3,3]-Sigmatropic Oxo-Rearrangements.

Architecture underlies the thermomechanical properties of polymers. Yet, few strategies are available to tune a polymer's architecture after it is prepared without altering its chemical composition. The ability to edit the architecture of a polymer would dramatically expand the accessible architecture-property space of polymeric materials.

3-Ethyl-6-vinyltetrahydro-2-pyran-2-one (EVP): a versatile CO-derived lactone platform for polymer synthesis.

3-Ethyl-6-vinyltetrahydro-2-pyran-2-one (EVP) is a CO-derived lactone synthesized Pd-catalyzed telomerization of butadiene. As EVP is 28.9% by weight CO, it has received significant recent attention as an intermediary for the synthesis of high CO-content polymers.

Tunable and recyclable polyesters from CO and butadiene.

Carbon dioxide is inexpensive and abundant, and its prevalence as waste makes it attractive as a sustainable chemical feedstock. Although there are examples of copolymerizations of CO with high-energy monomers, the direct copolymerization of CO with olefins has not been reported. Here an alternative route to functionalizable, recyclable polyesters derived from CO, butadiene and hydrogen via an intermediary lactone, 3-ethyl-6-vinyltetrahydro-2H-pyran-2-one, is described.

Sequencing of Sequence-Defined Oligourethanes via Controlled Self-Immolation.

Sequence-defined polymers show promise for biomimetics, self-assembly, catalysis, and information storage, wherein the primary structure begets complex chemical processes. Here we report the solution-phase and the high-yielding solid-phase syntheses of discrete oligourethanes and methods for their self-immolative sequencing, resulting in rapid and robust characterization of this class of oligomers and polymers, without the use of MS/MS. Crucial to the sequencing is the inherent reactivity of the terminal alcohol to "unzip" the oligomers, in a controlled and iterative fashion, releasing each monomer as a 2-oxazolidinone.