Protecting-Group-Free Iterative Divergent/Convergent Method for Preparing Sequence-Defined Polymers

• Published in: Macromolecules 2023-02, Vol.56 (3), p.1045-1052
• Main Authors: Ren, Xiangzhu, Guo, Changjuan, Li, Xijuan, Wu, Ying, Zhang, Yu, Li, Shumu, Zhang, Ke
• Format: Article
• Language: English
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/acs.macromol.2c02090

A new iterative growth method is reported to prepare monodisperse sequence-defined polymers by combining the chain growth mechanisms of the traditional iterative sequential growth (ISG) and iterative exponential growth (IEG) strategies. Using three orthogonal click reactions to couple three groups of monomers, each containing two orthogonal clickable groups. This method grows monodisperse sequence-defined polymers in a protecting-group-free divergent/convergent way. Each iterative cycle of this method involves two divergent sequential growth steps and one convergent exponential growth step, which endows the new method with the chain growth advantages of both traditional ISG and IEG. The two divergent sequential growth reactions introduce new monomer structures into main chains and provide the resultant sequence-defined polymers with varied monomer sequences, while the convergent exponential growth reaction guarantees the method a fast chain growth speed. The repetition of the abovementioned iterative cycle allows this method to grow monodisperse sequence-defined polymers with a fast chain growth manner of 3 × 2 n –2.