Suzuki Polycondensation toward High Molecular Weight Poly(m-phenylene)s: Mechanistic Insights and End-Functionalization
Suzuki Polycondensation toward High Molecular Weight Poly(m-phenylene)s: Mechanistic Insights and End-Functionalization
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DOI：
10.1021/ma300888j
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发表时间：
2012-06
期刊：
影响因子：
5.5
通讯作者：
B. Hohl;Louis Bertschi;Xiangyang Zhang;A. Schlüter;J. Sakamoto
中科院分区：
文献类型：
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作者：
B. Hohl;Louis Bertschi;Xiangyang Zhang;A. Schlüter;J. Sakamoto
报道了以ab型间苯单体（a和B分别代表溴官能团和硼官能团）为原料，采用铃木缩聚法合成聚间苯（SPC）。尽管尝试了高分子量产品，但在常规条件下使用Pd[P(P - tol)3]3作为催化剂的SPC只产生低聚物产品。它们包括环和具有不同端基图案的开链聚（间苯）s系列。这些图案是由配体乱序等副反应引起的。因此，Buchwald的SPhos配体可选择性地用于高周转率催化，以加速SPC超过此类有害副反应。这种修饰确实导致形成高分子量的产物~ 40 kDa (DP ~ 210)，而低聚环产物仍然突出。然而，通过缓慢的单体添加，可以大大减少循环的形成。SPC也在过量单功能化合物R-A或R-B的存在下进行。分子量…
Synthesis of a poly(m-phenylene) by Suzuki polycondensation (SPC) using an AB-type m-phenylene monomer is reported (A and B refer to bromo and boron functional groups, respectively). Despite the attempted high molecular weight products, SPC under the conventional conditions using Pd[P(p-Tol)3]3 as catalyst gave rise to oligomeric products only. They comprise cycles and several series of open-chain poly(m-phenylene)s with various end group patterns. These patterns were caused by side reactions such as ligand scrambling. Buchwald’s SPhos ligand was therefore alternatively employed for high turnover catalysis to accelerate SPC over such detrimental side reactions. This modification indeed led to the formation of high molecular weight products ∼40 kDa (DP ∼ 210), while oligomeric cyclic products still remained prominent. Cycle formation could, however, drastically be reduced by slow monomer addition. SPC was also performed in the presence of an excess monofunctional compound, R–A or R–B. The molecular weights...