Coding and decoding libraries of sequence-defined functional copolymers synthesized via photoligation

Abstract

Designing artificial macromolecules with absolute sequence order represents a considerable challenge. Here we report an advanced light-induced avenue to monodisperse sequence-defined functional linear macromolecules up to decamers via a unique photochemical approach. The versatility of the synthetic strategy—combining sequential and modular concepts—enables the synthesis of perfect macromolecules varying in chemical constitution and topology. Specific functions are placed at arbitrary positions along the chain via the successive addition of monomer units and blocks, leading to a library of functional homopolymers, alternating copolymers and block copolymers. The in-depth characterization of each sequence-defined chain confirms the precision nature of the macromolecules. Decoding of the functional information contained in the molecular structure is achieved via tandem mass spectrometry without recourse to their synthetic history, showing that the sequence information can be read. We submit that the presented photochemical strategy is a viable and advanced concept for coding individual monomer units along a macromolecular chain.

Recent Progress in the Design of Monodisperse, Sequence-Defined Macromolecules

“…This approach does not allow the introduction of side chains, but structural variation can be obtained, if a set of monomers is synthesized and applied in the iterative approach towards sequence‐defined macromolecules. The structural variation using photochemical pathways was very recently shown by the same group for the synthesis of symmetric decamers making use of a set of six different monomers . The monomers are equipped with a furan‐protected maleimide function as well as an α‐methyl benzaldehyde, which can be photochemically activated to a photo‐enol function allowing chain elongation by Diels–Alder reactions.…”

A Combined Photochemical and Multicomponent Reaction Approach to Precision Oligomers

“…Modular chain growth employing larger sequence‐defined building blocks instead of single monomers for coupling contributes to the overall reaction efficiency by an accelerated increase of the molecular weight for each synthetic step. Therefore, modular synthetic concepts significantly contributed towards a high level of control over sequence‐defined macromolecular formation processes . Herein, we extend the synthetic toolbox for preparing monodisperse multifunctional sequence‐defined macromolecules (i.e., unique according to IUPAC recommendations) by an approach combining highly efficient methods in an orthogonal fashion, that is the Passerini three‐component reaction (P‐3CR) and a photochemical reaction relying on a benzaldehyde species (photocaged dienes termed photoenols), as well as maleimides (Scheme ) .…”

A New Class of Materials: Sequence‐Defined Macromolecules and Their Emerging Applications

“…[12,13] Compared to DNA, synthetic polymer chemistry offers a unique opportunity to significantly increase the storage density. [8,15,16] Of course, designing macromolecules with distinct and facile fragmentation, [17,18] a computer assisted data interpretation [19] as well as a possible erasing of the data, [20] are essential to achieve practical application possibilities in the future. In terms of repeating units in sequence-defined macromolecules, this translates to the storage of one bit per repeat unit if a binary system (i.e., two different repeat units in a sequence-defined macromolecule) is used.…”