Jassas Rabab S, Mughal Ehsan Ullah, Sadiq Amina, Alsantali Reem I, Al-Rooqi Munirah M, Naeem Nafeesa, Moussa Ziad, Ahmed Saleh A
Department of Chemistry, Jamoum University College, Umm Al-Qura University 21955 Makkah Saudi Arabia.
Department of Chemistry, University of Gujrat Gujrat-50700 Pakistan
RSC Adv. 2021 Sep 29;11(51):32158-32202. doi: 10.1039/d1ra05910f. eCollection 2021 Sep 27.
Nanographenes, or extended polycyclic aromatic hydrocarbons, have been attracting increasing attention owing to their widespread applications in organic electronics. However, the atomically precise fabrication of nanographenes has thus far been achieved only through synthetic organic chemistry. Polycyclic aromatic hydrocarbons (PAHs) are popular research subjects due to their high stability, rigid planar structure, and characteristic optical spectra. The recent discovery of graphene, which can be regarded as giant PAH, has further stimulated research interest in this area. Chemists working with nanographene and heterocyclic analogs thereof have chosen it as their preferred tool for the assembly of large and complex architectures. The Scholl reaction has maintained significant relevance in contemporary organic synthesis with many advances in recent years and now ranks among the most useful C-C bond-forming processes for the generation of the π-conjugated frameworks of nanographene or their heterocyclic analogs. A broad range of oxidants and Lewis acids have found use in Scholl-type processes, including Cu(OTf)/AlCl, FeCl, MoCl, PIFA/BF-EtO, and DDQ, in combination with Brønsted or Lewis acids, and the surface-mediated reaction has found especially wide applications in PAH synthesis. Undoubtedly, the utility of the Scholl reaction is supreme in the construction of nanographene and their heterocyclic analogues. The detailed analysis of the progress achieved in this field reveals that many groups have contributed by pushing the boundary of structural possibilities, expanding into surface-assisted cyclodehydrogenation and developing new reagents. In this review, we highlight and discuss the recent modifications in the Scholl reaction for nanographene synthesis using numerous oxidant systems. In addition, the merits or demerits of each oxidative reagent is described herein.
纳米石墨烯，即扩展的多环芳烃，因其在有机电子学中的广泛应用而受到越来越多的关注。然而，迄今为止，纳米石墨烯的原子精确制造仅通过合成有机化学实现。多环芳烃（PAHs）因其高稳定性、刚性平面结构和特征光谱而成为热门研究对象。最近发现的石墨烯可被视为巨型PAH，这进一步激发了该领域的研究兴趣。研究纳米石墨烯及其杂环类似物的化学家已将其选为组装大型复杂结构的首选工具。近年来，肖尔反应在当代有机合成中一直保持着重要地位，取得了许多进展，现在已跻身于生成纳米石墨烯或其杂环类似物的π共轭骨架最有用的碳-碳键形成过程之列。多种氧化剂和路易斯酸已用于肖尔型反应，包括Cu(OTf)/AlCl、FeCl、MoCl、PIFA/BF-EtO和DDQ，与布朗斯特酸或路易斯酸结合使用，表面介导反应在PAH合成中得到了特别广泛的应用。毫无疑问，肖尔反应在纳米石墨烯及其杂环类似物的构建中具有至高无上的效用。对该领域取得的进展进行详细分析表明，许多研究小组通过拓展结构可能性的边界、扩展到表面辅助环脱氢反应以及开发新试剂做出了贡献。在这篇综述中，我们重点介绍并讨论了使用多种氧化剂体系的纳米石墨烯合成中肖尔反应的最新改进。此外，本文还描述了每种氧化试剂的优缺点。
