Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
J Am Chem Soc. 2014 May 28;136(21):7547-50. doi: 10.1021/ja502073k. Epub 2014 May 14.
Despite the high utility of aryne in organic synthesis, its polymerization has long been a significant challenge in polymer chemistry. A critical bottleneck in this process is the intrinsic instability of aryne and consequent short lifetime for polymerization. In order to circumvent the problem, we focus on a synthetic equivalent of aryne, [2.2.1]oxabicyclic alkene, as a monomer for polymerization. Palladium-catalyzed coordination-insertion polymerization of [2.2.1]oxabicyclic alkenes produced the corresponding polymers having an aliphatic main chain. Subsequent acid-promoted dehydration allowed the aliphatic main chain to be converted into an aromatic main chain to form poly(o-arylene)s. These sequential processes represent the first formal aryne polymerization, which offers an efficient method to synthesize a variety of poly(o-arylene)s in a chain-growth polymerization manner.
尽管芳炔在有机合成中具有很高的实用性，但将其聚合长期以来一直是聚合物化学中的一个重大挑战。这一过程中的一个关键瓶颈是芳炔的固有不稳定性和聚合反应的短暂寿命。为了解决这个问题，我们将注意力集中在芳炔的一种合成等价物，[2.2.1]氧杂双环烯烃，作为聚合反应的单体。钯催化的[2.2.1]氧杂双环烯烃的配位插入聚合反应产生了相应的聚合物，具有脂肪族主链。随后的酸促进脱水反应允许脂肪族主链转化为芳香族主链，形成聚（对亚芳基）。这些连续的过程代表了第一次正式的芳炔聚合反应，为以链增长聚合的方式合成各种聚（对亚芳基）提供了一种有效的方法。
