Step-economy approach for scalable synthesis of stereocontrolled and sequence-defined polyurethanes

Polyurethanes are widely used in industry due to their versatility across numerous applications. However, conventional step-growth polymerization methods inherently lack control over polyurethane's molar mass and monomer sequence, restricting their applications primarily to commodity materials. Unlocking a strategy to synthesize stereocontrolled, sequence-defined polyurethanes remains a formidable challenge, yet it holds the key to functional materials with properties tailored for specific applications. In this study, we present an approach that integrates one-pot oligomer synthesis with iterative exponential growth in solution, unlocking the fabrication of discrete, stereo-regulated polyurethanes with defined monomer sequences. The presented methodology enables the synthesis of 40-mer polyurethanes in fewer steps, eliminating yield losses typically associated with stepwise isolation in multistep solution synthesis. We also demonstrated the method's utility in preparing non-symmetrical polymer sequences. The stereocontrol seems to be a key parameter to modulate polymer folding and three-dimensional architectures, paving the way for scalable production of abiotic polymers that could mimic the structural characteristics of artificial proteins and unlock new possibilities for adapting material properties and functions for very specific applications.