INS1-0132
Sequence-defined vinyl macromolecules via iterative additions of acrylates
Topic
S1. Polymer Synthesis
When and Where
Oct 1, 2026
16:15 - 16:40
Room 101
Session Chairs
Byungjin KOO
Presenter(s)
Kyoung Taek Kim (Seoul National University)
Co-Author(s)
Abstract
Sequence-defined polymers have been successfully synthesized in recent years using multistep approaches such as solid-phase synthesis and iterative exponential growth (IEG). These synthetic macromolecules with defined molar masses and monomer sequences, herein abbreviated as “sequimers” for simplicity (sequi- means “to follow” in Latin and is the root of “sequence”), have been employed as precision building blocks for self-assembly and as molecular media for data storage, cryptography, and computing. Although well-defined vinyl polymers and copolymers have been synthesized by controlled radical polymerization methods, sequimers constructed from simple vinyl monomers remain elusive due to the lack of synthetic methods to ensure iterative addition of a single building block to a radical (or ionic) reactive center, forming a C–C bond without chain propagation.
In this presentation, we report the quantitative addition of a vinyl building block, an α-substituted acrylate, to a C-centered radical generated by visible-light-catalyzed photoredox decarboxylative addition (PhDA). The α-acyl radical site formed concomitantly upon addition of a bulky acrylate is irreversibly deactivated by rapid electron transfer within the photocatalytic cycle before oligomerization. The C-centered radical is regenerated only after conversion of the terminal ester to a carboxylic acid, followed by photoredox decarboxylation. Iterative PhDA (i-PhDA) of bulky acrylates proceeds quantitatively and rapidly, yielding vinyl sequimers composed of residues identical to the repeating units of conventional vinyl polymers, without chromatographic purification. i-PhDA of acrylates can be implemented to assemble aperiodic sequences of vinyl residues in continuous-flow reactors, potentially enabling rapid prototyping of sequimers to discover their sequence-dependent functions.
In this presentation, we report the quantitative addition of a vinyl building block, an α-substituted acrylate, to a C-centered radical generated by visible-light-catalyzed photoredox decarboxylative addition (PhDA). The α-acyl radical site formed concomitantly upon addition of a bulky acrylate is irreversibly deactivated by rapid electron transfer within the photocatalytic cycle before oligomerization. The C-centered radical is regenerated only after conversion of the terminal ester to a carboxylic acid, followed by photoredox decarboxylation. Iterative PhDA (i-PhDA) of bulky acrylates proceeds quantitatively and rapidly, yielding vinyl sequimers composed of residues identical to the repeating units of conventional vinyl polymers, without chromatographic purification. i-PhDA of acrylates can be implemented to assemble aperiodic sequences of vinyl residues in continuous-flow reactors, potentially enabling rapid prototyping of sequimers to discover their sequence-dependent functions.
