Polymer Journal ( IF 2.3 ) Pub Date : 2021-07-05 , DOI: 10.1038/s41428-021-00522-x Hae-Nam Choi 1 , In-Hwan Lee 2
Alcohol end-functionalized poly(3-hexylthiophene) (P3HT-OH) is a high-value material used for the generation of conjugated P3HT-coil block copolymers via controlled polymerization methods. Previously, P3HT-OH was prepared by Kumada catalyst-transfer polycondensation, which required effort-intensive postpolymerization modifications and additional protecting group techniques. Herein, we report the direct one-pot synthesis of P3HT-OH by Suzuki-Miyaura catalyst-transfer polycondensation. Mild reaction conditions with good functional group tolerance allowed the preparation of well-defined P3HT-OH without protective groups or postmodification processes. Notably, the [Pd]/[alcohol initiator] ratio should be ≤1 to obtain well-defined P3HT-OH because at this ratio the oxidation of the alcohol group is suppressed, which reduces end-group fidelity. Moreover, the polymerization should be quenched before full conversion of the monomer to prevent disproportionation into P3HT dimers. The high end-group fidelity of P3HT-OH was confirmed by block copolymerization with polystyrene through atom-transfer radical polymerization. Our protocol provides facile access to P3HT-OH, which is useful for small-molecule functionalization and block copolymer synthesis.
中文翻译:
醇端官能化聚(3-己基噻吩)的免保护一锅法合成
醇端官能化聚 (3-己基噻吩) (P3HT-OH) 是一种高价值材料,用于通过受控聚合方法生成共轭 P3HT 线圈嵌段共聚物。以前,P3HT-OH 是通过 Kumada 催化剂转移缩聚反应制备的,这需要大量的后聚合改性和额外的保护基团技术。在此,我们报告了通过 Suzuki-Miyaura 催化剂转移缩聚反应直接一锅法合成 P3HT-OH。具有良好官能团耐受性的温和反应条件允许在没有保护基团或后修饰过程的情况下制备明确定义的 P3HT-OH。值得注意的是,[Pd]/[醇引发剂] 比率应≤1 以获得明确定义的 P3HT-OH,因为在该比率下醇基的氧化被抑制,从而降低端基保真度。而且,在单体完全转化之前应停止聚合,以防止歧化为 P3HT 二聚体。通过原子转移自由基聚合与聚苯乙烯嵌段共聚,证实了 P3HT-OH 的高端基保真度。我们的协议提供了对 P3HT-OH 的轻松访问,这对于小分子功能化和嵌段共聚物合成很有用。