Harnessing IrAAC and SuFEx for the Efficient Synthesis of Sequence-Defined Oligomers with Diverse Side Groups

In this research, we demonstrate the successful synthesis of sequence-defined oligomers employing a novel orthogonal coupling strategy that integrates sulfur fluoride exchange (SuFEx) and iridium(I)-catalyzed alkyne–azide cycloaddition (IrAAC). This technique enables the precise construction of oligomers with well-defined sequences and a wide range of functional side groups, showcasing the exceptional control and versatility of this approach. Through the facile synthesis of bifunctional monomers capable of engaging in both SuFEx and IrAAC reactions, we have efficiently constructed oligomers with diverse functionalities. These oligomers were rigorously characterized using size exclusion chromatography (SEC), ¹H NMR, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF-MS), confirming their high uniformity and sequence accuracy. Further, we enhanced the versatility of these oligomers by employing the thiol-Michael addition reaction for postmodification, thereby broadening the scope of potential polymer structures and applications. This approach highlights the adaptability and broad applicational potential of our synthetic strategy in advanced polymer chemistry.