Roemer Max, Lewis William
School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia.
Sydney Analytical Core Research Facility, The University of Sydney, Sydney, New South Wales 2006, Australia.
Langmuir. 2023 Sep 26;39(38):13560-13570. doi: 10.1021/acs.langmuir.3c01597. Epub 2023 Aug 16.
Copper nanostructures were obtained from the reduction of Cu(I) under mild conditions in ethanol/water using sodium-l-ascorbate and sodium azide while performing an amination reaction. When the halobenzene substrate was reacted in the presence of a bulk carbon black (CB) support, clustered copper sub-micrometer particles (SMPs) and microparticles (MPs) form. The growth conditions of the MPs were optimized, and the supported nanostructures were isolated and characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetry, and inductively-coupled plasma mass spectrometry. The particles are mobile and supported within the CB matrix and proved to be active catalysts in the azide-alkyne cycloaddition (CuAAC). The catalytic competency of the particles was assessed in a two-step three-component azide-alkyne cycloaddition of benzyl bromide, sodium azide, and phenylacetylene as a model reaction. The reaction conditions were optimized, and the optimized conditions were applied for the synthesis of triazole compounds with varying levels of functionalization. The recyclability of the catalysts was investigated, depletion modes were discussed, and the conditions were fine-tuned to reach good recyclability. This demonstrates the broader applicability of the SMPs/MPs as CuAAC-catalyst and its limitations.
在进行胺化反应时，使用l -抗坏血酸钠和叠氮化钠在乙醇/水的温和条件下还原Cu(I)，从而获得铜纳米结构。当卤代苯底物在块状炭黑（CB）载体存在下反应时，会形成聚集的亚微米级铜颗粒（SMPs）和微米级颗粒（MPs）。对MPs的生长条件进行了优化，并通过扫描电子显微镜、能量色散X射线光谱、热重分析和电感耦合等离子体质谱对负载的纳米结构进行了分离和表征。这些颗粒可移动并负载在CB基质中，并且在叠氮化物-炔烃环加成反应（CuAAC）中被证明是活性催化剂。以苄基溴、叠氮化钠和苯乙炔的两步三组分叠氮化物-炔烃环加成反应作为模型反应，评估了颗粒的催化能力。对反应条件进行了优化，并将优化后的条件应用于合成具有不同官能化水平的三唑化合物。研究了催化剂的可回收性，讨论了消耗模式，并对条件进行了微调以实现良好的可回收性。这证明了SMPs/MPs作为CuAAC催化剂的更广泛适用性及其局限性。
