Synthesis of Dendrimer‐Like Helical Poly(Phenyl Isocyanide)s Using Air‐Stable Palladium Complexes with Double Arms

• Published in: Macromolecular chemistry and physics 2020-12, Vol.221 (24), p.n/a
• Main Authors: Lin, Min, Wu, Qi‐Liang, Li, Qian‐Wei, Hou, Xiao‐Hua, Zou, Hui
• Format: Article
• Language: English
• Subjects: Catalysts; Chemical synthesis; dendritic polymers; helices; Molecular weight; Molecular weight distribution; Monomers; Palladium; poly(phenyl isocyanide); Polymers; Transesterification
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.202000362

A new stepwise iterative method is developed for the synthesis of well‐defined dendrimer‐like helical poly(phenyl isocyanide)s (PPIs). The method mainly involves the following three reaction steps in an iterative process: 1) the polymerization of decyl 4‐isocyanobenzoate (monomer 1) or 4‐isocyanobenzoyl‐2‐aminoisobutyric acid decyl ester (monomer 2) to afford the polymer, 2) reacting one pentafluorophenyl (PFP) ester‐functionalized phenyl isocyanide (monomer 3) at the end of the polymer, followed by the treating of PPh3 to remove the ‐Pd(PEt3)2Cl groups, and 3) the transesterification reaction of the PFP group with hydroxyl functionalized palladium catalyst (catalyst 1) to introduce two ‐Pd(PEt3)2Cl groups at the end of the polymer, which can be used as the next initiating site. Repeating the above three reaction steps, (1), (2) and (3), enables the synthesis of high‐generation and high‐molecular‐weight dendrimer‐like helical PPIs. In practice, a series of dendrimer‐like helical poly‐1ns and poly‐2ms up to the fourth generation (4G) are successfully synthesized. The molecular weight (Mn) of the final 4G dendrimer‐like poly‐1ns and poly‐2ms is 49.4 and 66.5 kDa, respectively and they are both with narrow molecular weight distribution. A new stepwise iterative method is developed for the synthesis of well‐defined dendrimer‐like helical poly(phenyl isocyanide)s (PPIs) with high‐generation, high‐molecular‐weight, and narrow molecular weight distribution. A series of dendrimer‐like helical poly‐1ns and poly‐2ms up to the fourth generation (4G) are successfully synthesized. The molecular weight (Mn) of the final 4G dendrimer‐like poly‐1ns and poly‐2ms is 49.4 and 66.5 kDa, respectively.