Sequencing of Sequence-Defined Oligourethanes via Controlled Self-Immolation
Samuel D. Dahlhauser, P. Rogelio Escamilla, Abigail N. VandeWalle, Jordan T. York, Rachel M. Rapagnani, Jasper S. Shei, Samuel A. Glass, Jaime N. Coronado, Sarah R. Moor, Douglas P. Saunders, Eric V. Anslyn
Abstract
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. By monitoring the self-immolation reaction via LC/MS, an applied algorithm rapidly produces the sequence of the oligourethane. Not only does this process provide characterization of structurally complex molecules, it works as a reader of molecular information.