Mechanistic Investigation of Catalyst-Transfer Suzuki-Miyaura Condensation Polymerization of Thiophene-Pyridine Biaryl Monomers with the Aid of Model Reactions
作者:Yu Tokita、Masaru Katoh、Yoshihiro Ohta、Tsutomu Yokozawa
DOI:10.1002/chem.201603581
日期:2016.11.21
of the disubstitution product. Therefore, step‐growth polymerization appears to be due to intermolecular transfer of the Pd catalyst from Th after reductive elimination of the Th‐Pd‐Py complex formed by transmetalation of polymer Th–Br with (Pin)B–Py–Th–Br monomer 12 (Pin=pinacol). Catalysts with similar stabilization energies of metal–arene η2‐coordination for D and A monomers may be needed for CTCP
我们研究了2-烷氧基丙基-6-(5-溴噻吩-2-基)-3-(4,4,5,)的有效Pd催化Suzuki-Miyaura催化剂转移缩聚(Pd-CTCP)反应的要求5-四甲基-1,3,2-二氧杂硼硼烷-2-基)吡啶(12)作为供体-受体(D -A)联芳基单体。作为模型反应,我们首先通过使用t进行了X–Py–Th–X'(Th =噻吩,Py =吡啶,X,X'= Br或I)1与苯基硼酸酯2的Suzuki-Miyaura偶联反应。以Bu 3 PPd 0为催化剂。在Th‐I处带有苯基的单取代主要发生在Br–Py–Th–I(1 b)与2然而,I-Py-Th-Br(1 c)与2的反应中选择性地发生了不稳定性,表明Pd催化剂在分子内从受体Py转移到供体Th。因此,我们通过将硼酸酯部分和溴分别引入Py和Th中来合成单体12。但是,检查单体转化率与所得聚合物的M n之间的关系,以及基质辅助激光解吸电离飞行时间(MA