Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States.
J Am Chem Soc. 2020 Aug 26;142(34):14427-14431. doi: 10.1021/jacs.0c05454. Epub 2020 Aug 12.
Although widely used in catalysis, the multistep syntheses and high loadings typically employed are limiting broader implementation of highly active tailor-made arylborane Lewis acids and Lewis pairs. Attempts at developing recyclable systems have thus far met with limited success, as general and versatile platforms are yet to be developed. We demonstrate a novel approach that is based on the excellent control and functional group tolerance of ring-opening metathesis polymerization (ROMP). The ROMP of highly Lewis acidic borane-functionalized phenylnorbornenes afforded both a soluble linear copolymer and a cross-linked organogel. The polymers proved highly efficient as recyclable catalysts in the reductive -alkylation of arylamines under mild conditions and at exceptionally low catalyst loadings. The modular design presented herein can be readily adapted to other finely tuned triarylboranes, enabling wide applications of ROMP-borane polymers as well-defined supported organocatalysts.
虽然在催化中广泛应用，但多步合成和高负载通常会限制高活性定制芳基硼烷路易斯酸和路易斯对的更广泛应用。因此，开发可回收系统的尝试迄今取得的成功有限，因为尚未开发出通用且多功能的平台。我们展示了一种基于开环复分解聚合 (ROMP) 的出色控制和官能团耐受性的新方法。高度路易斯酸性硼烷官能化的苯并降冰片烯的 ROMP 提供了可溶性线性共聚物和交联有机凝胶。这些聚合物在温和条件下和极低的催化剂负载下，作为芳烃胺还原烷基化反应的可回收催化剂，效率非常高。本文提出的模块化设计可以很容易地适应其他精细调整的三芳基硼烷，从而使 ROMP-硼烷聚合物作为明确定义的负载型有机催化剂得到广泛应用。
