Hetero-polycyclic aromatic systems: A data-driven investigation of structure–property relationships

• Sabyasachi Chakraborty,
• Eduardo Mayo Yanes and
• Renana Gershoni-Poranne

Beilstein J. Org. Chem. 2024, 20, 1817–1830, doi:10.3762/bjoc.20.160

• on a range of electronic molecular properties of PASs. Keywords: computational chemistry; database; dataset; π-conjugated; polycyclic aromatic hydrocarbons; polycyclic aromatic systems; Introduction Polycyclic aromatic systems (PASs) – molecules made up of fused aromatic rings – are among the most

• to hypothesize that the presence of antiaromatic moieties in the linear stretch (cyclobutadiene and/or 1,4-dihydro-1,4-diborinine) may be distorting the results. In other words, perhaps the effect is only relevant to linear stretches of aromatic rings. To verify this, we identified within the same

• molecules the longest linear stretch comprising only aromatic rings. These distributions (shown in Figure 5B) do indeed show a clearer trend, but it is still weaker than the cc-PBHs. Therefore, in the next step, we plotted the distributions of all 9-ring molecules containing only aromatic building blocks

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

• Adam D. Bass,
• Daniela Castellanos,
• Xavier A. Calicdan and
• Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

• cyclic imides. The solid-state structures of the N-phenyl derivatives, determined by X-ray crystallography, reveal changes in packing preference based on the number of aromatic rings in the core. The optical and electronic properties of the title compounds compare favorably with other previously

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• cation is formed with two resonance structures (not counting further movement into the other aromatic rings destroying the aromaticity of one more ring). Resonance structure A has the cation in a benzylic position and will be the preferred site for nucleophilic attack of methanol compared to resonance

Synthesis of 1,2,3-triazoles containing an allomaltol moiety from substituted pyrano[2,3-d]isoxazolones via base-promoted Boulton–Katritzky rearrangement

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 1334–1340, doi:10.3762/bjoc.20.117

• prepare an array of target 1,2,3-triazoles 4 with allomaltol unit (Scheme 4). It is interesting to note that the recyclization products can be synthesized in good yields employing various starting arylhydrazones 3 both with donor and acceptor substituents at aromatic rings. Besides that, heterocyclic

Recent developments in the engineered biosynthesis of fungal meroterpenoids

• Zhiyang Quan and
• Takayoshi Awakawa

Beilstein J. Org. Chem. 2024, 20, 578–588, doi:10.3762/bjoc.20.50

• cross-coupling between two aromatic rings [43]. In the future, further developments in bioinformatics, structural biology, and AI techniques will enable the design of biosynthetic enzymes and pathways to produce desired bioactive compounds, although understanding the chemistry catalyzed by individual

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• also developed tweezers 35 with a semi-rigid 1,4-diphenyl-1,3-butadiyne spacer containing two urea units linked to the aromatic rings and Zn–porphyrin functional units (Figure 19b) [77]. The arms have a free rotation around the rigid diethylene backbone and thus the system is natively in equilibrium

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• melting point of indigo is bifurcated intra- and intermolecular hydrogen bonding [11], and face-to-face π–π stacking of parallel aromatic rings (Figure 2) [12]. Single crystal X-ray diffraction analysis showed that the indigo molecule is almost planar and exists in the E-conformation. The central C=C bond

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• bands were observed in the 1400–1500 cm−1 region (Table 2). These patterns, often a doublet, were tentatively assigned to skeletal vibrations involving C=C stretching of the aromatic rings, although the intervention of asymmetrical CH deformation modes (e.g., bending or scissoring) could not be excluded

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• affinity and selectivity of the R[4]A–amine complexes depend on several factors, including the size, shape, and functional groups of both the host and the guest molecules. For example, R[4]A derivatives with different substituents on the aromatic rings [12] have been synthesized to enhance the binding

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• -rich enones 2o,t,u, bearing electron-donating substituents in the aromatic rings, afford complex mixtures of oligomeric materials. The cyclization of hydroxy ketone 1k into indanone 3k is accompanied by demethylation of one of the methoxy groups (Scheme 6). The positions of hydroxy and methoxy groups

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• method allows the efficient alkylation of aromatic rings, can directly afford pharmaceutically significant heterocycles, and the raw materials and iron catalysts are safe and readily available. In 2017, Xu, Loh, and co-workers, demonstrated an iron-catalyzed hydroalkylation reaction of α,β-unsaturated

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• anthracenyl group of the catalyst framework and aromatic rings of both substrates was also responsible for the stereoselective addition (Scheme 14) [39]. In 2019, Akiyama and co-workers developed a simple enantioselective aza-Friedel–Crafts process using unprotected pyrroles 9 and indoles 4 mediated by BINOL

Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO₂F₂)

• Xian-Lin Chen and
• Hua-Li Qin

Beilstein J. Org. Chem. 2023, 19, 901–908, doi:10.3762/bjoc.19.68

• %). Notably, the efficiency of this transformation was greatly impacted by the electronic effect on the aromatic rings of the olefins. Alkenes with electron-donating groups on their aromatic rings showed higher yields of the corresponding products as compared to those with electron-withdrawing groups (3af–ar

• ). Furthermore, the desired products were not even obtained when the starting materials were connected to extra strong electron-withdrawing groups (such as a nitro group) on their aromatic rings. In addition, a series of cyclobutanone oxime derivatives were also smoothly transformed into the corresponding

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• serve as bioisostere for aromatic rings, amines, amides, and N-containing heterocycles. Due to the aforementioned qualities, numerous U.S. FDA-approved medications have pyridine scaffolds in their molecules (Figure 1). In this context, the synthesis of the pyridine motif is always there in trend. Many

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

• Joydev K. Laha,
• Pankaj Gupta and
• Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

• investigated the substrate scope for the above transformation (Scheme 2). A limited variety of N-(arylsulfonyl)benzylamines 1a–m carrying substitutions on the aromatic rings was examined. Firstly, N-(arylsulfonyl)benzylamines having substitution(s) on one or both rings delivered the N-arylsulfonylimines 2a–h

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• etherification entails the palladium or copper-catalysed formation of a carbon–heteroatom bond. Despite significant successes and facile access to the core tricyclic motif, access to dibenzo[b,f]heteropines with disparately substituted aromatic rings fused to the heterocyclic ring and varied substitution

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• -Cl [21], 3,4-di-Cl [21][22], 2/3/4-F [23]) were inserted in the N-benzyl moiety as well as in the aromatic rings of the benzophenone fragment [24][25][26] (selected examples are given in Scheme 1). Insertion of halogen atoms increased enantioselectivity, e.g., in alkylation reactions [27][28

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• solubility decreases with the increased number of aromatic rings in a molecule [18]. Pentacene with five conjugated aromatic rings has been extensively investigated; however, it is quite challenging to investigate the spectral and electrical properties of acenes with a number of rings higher than 6 because

• might be achieved by a supramolecular interaction with a suitable host. Our initial plan was to enhance the solubility of higher acenes by the complexation with CDs. However, linear acenes with more aromatic rings (such as pentacene or heptacene) are, in addition to their poor solubility, also quite

New triazole-substituted triterpene derivatives exhibiting anti-RSV activity: synthesis, biological evaluation, and molecular modeling

• Elenilson F. da Silva,
• Krist Helen Antunes Fernandes,
• Denise Diedrich,
• Jessica Gotardi,
• Marcia Silvana Freire Franco,
• Carlos Henrique Tomich de Paula da Silva,
• Ana Paula Duarte de Souza and
• Simone Cristina Baggio Gnoatto

Beilstein J. Org. Chem. 2022, 18, 1524–1531, doi:10.3762/bjoc.18.161

• -1,2,3-triazole (at C-28 position) of compound 8 mimicked the phosphate group and triazole ring of crystallographic ligands, respectively. In addition, the triterpene skeleton of compound 8 was located at the same region occupied by the aromatic rings of both IMP and inhibitor MAD1 ligands (Figure 3

An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

• Stephen J. I. Shearan,
• Enrico Andreoli and
• Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

• construction of metal phosphonate frameworks, two main considerations were made when selecting these substrates with regards to rigidity and geometry (Figure S1, Supporting Information File 1). In the compounds considered here, rigidity is ensured by the network of sp2-hybridized carbon atoms, or aromatic

• rings, and is important to ensure stability in the potential MOF structures derived from the proposed linkers. The geometry of these linkers, termed as V-shaped, was selected to try and move away from the pillared-layered structures that are obtained when using linear diphosphonate linkers, which are

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• HMBC signals (H-2’ to C-1’, C-4’, C-6’; H-3’ to C-1’, C-5’; H-4’ to C-2’, C-6’ ; H-5’ to C-1’, C-3’; H-2’’ to C-1’’, C-4’’, C-6’’; H-3’’ to C-1’’, C-5’’; H-4’’ to C-2’’, C-6’’, and H-5’’ to C-1’’, C-3’’) of compound 1 indicated the presence of two mono-substituted aromatic rings. The cross-peaks from H

Automated grindstone chemistry: a simple and facile way for PEG-assisted stoichiometry-controlled halogenation of phenols and anilines using N-halosuccinimides

• Dharmendra Das,
• Akhil A. Bhosle,
• Amrita Chatterjee and
• Mainak Banerjee

Beilstein J. Org. Chem. 2022, 18, 999–1008, doi:10.3762/bjoc.18.100

• observed for 4-phenylphenol indicating this electrophilic halogenation is selective to electron-rich aromatic rings only (product 2f, Scheme 3). Also, aromatic halogenation prevails over α-halogenation of a ketomethyl group as was demonstrated by the formation of product 2m as the sole product for the

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• s−1. Keywords: dithienothiophene (DTT); fused ring system; organic field-effect transistor (OFET); organic semiconductor; thienoacene; Introduction In recent years, organic molecules with several fused aromatic rings have gained much attention. Fusing aromatic rings leads to planar structures

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• yet been discovered. Phenolic sesquiterpenoids, for instance, illudacetalic acid and illudinine from Omphalotus olearius, were also discovered. Based on bioinformatics analysis, their aromatic rings were proposed to be constructed by putative P450 enzymes or oxidoreductase [33]. The Huang group