On the Shape and Synthesis of Extended Fluorenones: Recent Advances and Upcoming Challenges

Abstract

Extended fluorenones represent a particular class of polycyclic compounds. The extension of the aromatic system through the fusion of additional benzene rings onto the central tricyclic fluorenone gives rise to an impressive topological diversity and allows to modulate the properties of the original molecule. The multiple ways this aromatic extension can be joined onto the tricyclic core generates multiple spatial arrangements from linear, angular, mixed linear-angular, to helical. This extensive range of shapes and their subsequent applications has piqued the curiosity of the scientific community, who now creatively compete to develop selective and direct routes to these valuable molecular architectures. Potential applications of these diverse domains have also driven the development of strategies for the installation of various substituents at selected sites of the carbon backbone. This review intends to provide the reader with an up-to-date overview of the methods for constructing extended fluorenones and their properties. Damien Prim studied chemistry at the Paul Verlaine University of Metz, where he received his Ph.D. in organic chemistry in 1994 under the guidance of Prof. Gilbert Kirsch. After a postdoctoral period with Prof. Léon Ghosez at UC Louvain-la-Neuve, Belgium, he was appointed as an assistant professor at Paul Verlaine University of Metz. In 1999, he moved to Pierre et Marie Curie University in Paris as a CNRS research associate. He then moved to the University of Versailles St Quentin as an assistant professor in 2001. In 2005, he was appointed as a full professor of chemistry at the University of Versailles St Quentin. Since 2020, he has been head of the Graduate School of Chemistry at the University of Paris-Saclay. His research focuses on homogeneous and heterogenous catalysis and the syntheses and properties of polycyclic molecular architectures. Benjamin Large studied chemistry at the Ecole Nationale Supérieure de Chimie de Montpellier, France, and then joined Damien Prim's team at the University of Versailles St Quentin as a Ph.D. student. His thesis was focused on the selective C-H functionalization of naphthalene and its derivatives. After obtaining his Ph.D. in 2019, Benjamin joined Anne-Kathrin Duhme-Klair's team as a postdoctoral research associate at the University of York (UK), and is currently working on the development of artificial metalloenzymes

Indeno-Annulation of o-Formyl-Ynones, o-Bis-Ynones, and p-Bis-o-Formyl-Ynones with Dimethyl Acetone-1,3-Dicarboxylate: One Flask Cascade Synthesis of Functionally Endowed 9-Fluorenols and Indeno[1,2-b]fluorenols

“…Mechanistically, the formation of Indeno­[1,2- b ]­fluorene-6,12-diols 15a–c can be understood in terms of two sequential indenoannulations on the two o -formyl ynone moieties present as per the conceptualization depicted in Figure . While several synthetic approaches to extended fluorenones like indeno­[1,2- b ]­fluorenediones have been reported in recent years, the present offering to access these deca-functionalized entities, possibly a record, through a notably concise (one-pot) and flexible strategy under ambient conditions is quite unique and adaptable for scale-up. In this context, it may be recalled that access to indenofluorene (IF) framework, particularly to its donor–acceptor, and highly substituted derivatives is a significant advance as they have drawn considerable traction in recent years as n-type organic semiconductors for possible applications as optoelectronic materials in areas related to nonlinear optics, molecular spintronics, and organic photovoltaic devices. , …”

“…The foregoing synthesis of variegated 9-fluorenols raised our confidence in the viability of the proposed indenoannulation strategy (Figure 1) to rapidly access fused fluorene-based polycyclic aromatic systems, and we next ventured to implement it on specially crafted p-bis-o-formyl ynones of General conditions are as follows: 1a (1 equiv), 9 (1.1 equiv), base, solvent (2 mL) and performed at room temperature (∼25 °C) for 1 h. 18 the present offering to access these deca-functionalized entities, possibly a record, through a notably concise (one-pot) and flexible strategy under ambient conditions is quite unique and adaptable for scale-up. In this context, it may be recalled that access to indenofluorene (IF) framework, particularly to its donor−acceptor, and highly substituted derivatives is a significant advance as they have drawn considerable traction in recent years as n-type organic semiconductors for possible applications as optoelectronic materials in areas related to nonlinear optics, molecular spintronics, and organic photovoltaic devices.…”

Electricity-Promoted Friedel–Crafts Acylation of Biarylcarboxylic Acids

“…The fluorenone architecture and its derivatives are common motifs in natural products, biological active, and optoelectronic compounds (Scheme ). Accordingly, many synthetic strategies, such as the oxidation of fluorenes, transition-metal-catalyzed C–H activation, radical cyclization, have been devised to access fluorenones, and the development of novel strategies remains a valuable undertaking. One of the most convenient and practical approaches to fluorenones is the Friedel–Crafts acylation of biarylcarboxylic acids and their acyl chlorides .…”

Synthesis, properties, and application of phenanthrenone: an undeveloped building block and a photocatalyst

“…1a). Fluorenone 2 as one of the most important derivatives of benzophenone is widely used in materials sciences, 3 photocatalysis, 4 and medicinal chemistry 5 , which encouraged us to develop more new and useful scaffolds to widen the library of building blocks and introduce new properties and applications in the new scaffolds.…”