A Combined Photochemical and Multicomponent Reaction Approach to Precision Oligomers

We introduce the convergent synthesis of linear monodisperse sequence‐defined oligomers through a unique approach, combining the Passerini three‐component reaction (P‐3CR) and a Diels–Alder (DA) reaction based on photocaged dienes. A set of oligomers is prepared resting on a Passerini linker unit carrying an isocyano group for chain extension by P‐3CR and a maleimide moiety for photoenol conjugation enabling a modular approach for chain growth. Monodisperse oligomers are accessible in a stepwise fashion by switching between both reaction types. Employing sebacic acid as a core unit allows the synthesis of a library of symmetric sequence‐defined oligomers. The oligomers consist of alternating P‐3CR and photoblocks with molecular weights up to 3532.16 g mol−1, demonstrating the successful switching from P‐3CR to photoenol conjugation. In‐depth characterization was carried out including size‐exclusion chromatography (SEC), high‐resolution electrospray ionization mass spectrometry (ESI‐MS) and NMR spectroscopy, evidencing the monodisperse nature of the precision oligomers.