Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

• Yang Chen,
• Jiao He,
• Hang Lin,
• Hai-Feng Wang,
• Ping Hu,
• Bi-Qin Wang,
• Ke-Qing Zhao and
• Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

• an effective tool for the design of liquid crystalline materials [3][4][5][6][7][8]. Rod-like liquid crystalline molecules with fluorine-substituted arenes are ubiquitous in the displays industry [12]. They are also gaining importance in the design of π-conjugated polycyclic aromatic discotic liquid

• , with a multitude of sharp peaks, that could be indexed according to a rectangular lattice (p2gg symmetry) [50], confirming the reduction of the phase symmetry and well-defined interfaces between aliphatic continuum, hydrogenated aromatics, and fluorinated arenes. The S/WAXS patterns of the three

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• -fluorinated tosylated aziridines 15 with good tolerance to styrenyl arenes with electron-withdrawing groups on them. The yields of product dropped off significantly when the ring did not contain an electron-withdrawing group on it. In 2023, Šmit and co-workers conducted an in-depth mechanistic study on the

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• resulting C-centered radical A with tert-butylperoxy radical lead to the tert-butylperoxy cyclohexane 84. C(sp2)–X peroxidation of arenes The radical peroxidation of the aromatic core has been realized on the example of the peroxidation of phenols [83][84][85][86][87][88][89][90]. The first studies were

• ]. It was shown that manganese salts in various oxidation states catalyze the peroxidation of styrenes with TBHP [129]. A method was proposed for the synthesis of [1,2-bis(tert-butylperoxy)ethyl]arenes 195 from styrenes 194 under Mn(OAc)3 catalysis (Scheme 61). The formation of active peroxidising

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• arenes were attained in good to excellent yields [56]. Additionally, the same reaction was further explored by using α-fluoro-α-nitrosulfonylmethanes as starting material under modified reaction conditions to yield the arylated α-fluoronitrosulfonylmethane [57]. Phenyl(mesityl)iodonium salt was employed

• rearrangement to form C(sp2)–O bonds without the need of metal catalysts [82]. In 2023, this approach was expanded to synthesize complex functionalized aromatic ring diaryliodonium salts [83]. Various aromatic rings, including multisubstituted arenes, conjugated arenes, oxygen and nitrogen heterocycles 78 were

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• vinyl allenylidene is the key intermediate during the process (Scheme 14). Recently, Fang et al. [67] used electron-rich arenes as the nucleophiles to achieve remote enantioselective control of yne-allylic substitutions. It is worth noting that when indoles or indolizines were used, the reactions

• yne-allylic sulfonylation. Proposed mechanism of yne-allylic sulfonylation. Aymmetric yne-allylic substitutions using indoles and indolizines. Double yne-allylic substitutions using pyrrole. Proposed mechanism of yne-allylic substitution using electron-rich arenes. Aymmetric yne-allylic

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

• Yuki Yamamoto,
• Yuki Konakazawa,
• Kohsuke Fujiwara and
• Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

• with halogen or triflate groups. Recently, transition-metal-catalyzed direct borylation of arenes via C–H bond activation has been reported, although the design of the substrate and ligands is somewhat complicated [16][17][18][19][20][21][22]. Since the complete removal of catalyst-derived metal

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• have been developed, the combination of electrochemistry with organocatalysis is generally less explored. In this context, Wang et al. combined organocatalysis and electrochemistry for the benzyl amination via C–H/N–H dehydrogenative cross-coupling of alkyl arenes with azoles [39]. According to the

• late-stage functionalizations. In 2020, Ackermann and coworkers reported the challenging C–H alkoxylation of (hetero)arenes with sterically encumbered secondary alcohols via a nickel electrocatalyzed protocol [49]. A traceless removable quinoline amide in the meta position was employed as a directing

• molecules. 1.3.6 Pd-assisted anodic oxidation. In 2023, Ackermann and coworkers reported a Pd-catalyzed anodic oxidation for the alkenylation of arenes without the need for directing groups [57]. Using Pd(OAc)2 as the catalyst, 2-methyl-2-(phenylthio)propanoic acid as the ligand, and 1,4-benzoquinone (BQ

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• efficient solvent for synthesizing resorcin[n]arenes in the presence of catalytic amounts of HCl at ambient temperature and within minutes. Remarkably, resorcinols with electron-withdrawing groups and halogens, which are reported in the literature as the most challenging precursors in this cyclization, are

• tolerated. This method leads to a variety of 2-substituted resorcin[n]arenes in a single synthetic step with isolated yields up to 98%. Keywords: cavitand; cyclization; HFIP; hydroxyalkylation; resorcinarenes; Introduction The acid-catalyzed aldehyde-resorcinol condensation has been studied for more than

• from intermolecular dehydration, nowadays known as alkyl resorcin[4]arene. Forty years later in 1980, Höegberg noticed that short alkyl chain resorcin[n]arenes develop stereoisomers in the reaction mixture; however, since the condensation reaction is reversible, once the macrocycle adopts the bowl

Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols

• Smaher E. Butt,
• Konrad Kepski,
• Jean-Marc Sotiropoulos and
• Wesley J. Moran

Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209

• provided slight improvements in yield (Table 1, entries 2–4). The more electron-rich 2-iodo-1,3-dimethoxybenzene led to a further increase in yield to 44% (Table 1, entry 5). 1,2-Diiodobenzene has been reported to be a superior precatalyst in intermolecular C–H aminations of arenes but only provided 40

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

• Yuri A. Sidunets,
• Valeriya G. Melekhina and
• Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

• of thus generated diazonium salts. In this regard, amide 2a and mesitylene were selected as model objects to optimize the reaction conditions, since azo coupling of (1,2,5-oxadiazolyl)diazonium salts with electron-donating arenes is known to proceed quantitatively [42]. We varied the diazotization

From perfluoroalkyl aryl sulfoxides to ortho thioethers

• Yang Li,
• Guillaume Dagousset,
• Emmanuel Magnier and
• Bruce Pégot

Beilstein J. Org. Chem. 2024, 20, 2108–2113, doi:10.3762/bjoc.20.181

• arenes in good yield. Inspired and stimulated by this abundant literature, and as part of our research program focused on creating novel perfluoroalkylsulfur derivatives, we became interested in a reappraisal of our previous study with the aim of increasing its scope as well as the yield and selectivity

Divergent role of PIDA and PIFA in the AlX₃ (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study

• Kevin A. Juárez-Ornelas,
• Manuel Solís-Hernández,
• Pedro Navarro-Santos,
• J. Oscar C. Jiménez-Halla and
• César R. Solorio-Alvarado

Beilstein J. Org. Chem. 2024, 20, 1580–1589, doi:10.3762/bjoc.20.141

• , Br) [26][27][28][29][30][31]. So far, different protocols for the halogenation of arenes using iodine(III) reagents have been described, mainly using (diacetoxyiodo)benzene (PIDA)/TMSCl, PIDA/TMSBr [32], and [bis(trifluoroacetoxy)iodo]benzene (PIFA)/TMSBr [33]. We have recently developed a new

• protocol for the oxidative chlorination and bromination of naphthols using the PIFA/AlCl3 [26] and PIDA/AlBr3 [28][29] systems. These unprecedented protocols combined iodine(III) reagents and aluminum salts to achieve chlorination and bromination of electron-rich arenes under mild and experimentally

• protocol for the electrophilic bromination of arenes, mainly phenols [28][29]. Accordingly, the bromination reaction was initially explored by mixing PIFA and AlBr3, which gave an acceptable yield (84%). However, other iodine(III) reagents were tested as oxidants during the optimization process. Thus, when

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• showed they were able to scale-up and selectively fluorinate the ibuprofen methyl ester at the methylene group to produce over 2 g of product 12. The utility of the benzyl fluoride products as strategic intermediates for benzylation of electron-rich arenes was demonstrated by the authors (Figure 41B

• fragility of secondary and tertiary benzyl fluorides, as they observe elimination and hydrolysis in many cases [20][100], thereby raising question marks over their suitability as synthetic targets. Monofluorinated methyl arenes, however, are much more stable to these decomposition pathways. The nucleophilic

Electrophotochemical metal-catalyzed synthesis of alkylnitriles from simple aliphatic carboxylic acids

• Yukang Wang,
• Yan Yao and
• Niankai Fu

Beilstein J. Org. Chem. 2024, 20, 1497–1503, doi:10.3762/bjoc.20.133

• that are susceptible to oxidative degradation under traditional chemical conditions. For example, electron-rich arenes (4–6) can be smoothly obtained in synthetically useful yields. Electron-withdrawing groups at the phenyl ring are also compatible to give the products with good yields (7). Furthermore

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

• Lu Li,
• Na Li,
• Xiao-Tian Mo,
• Ming-Wei Yuan,
• Lin Jiang and
• Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

• substrates [7][8]. Pre-functionalized arenes are essential precusors in all of these general approaches. 2-Cyclohexenones are fundamental and versatile organic synthetic materials [9][10]. They have been applied as an ideal arylation platform to construct functionalized anilines via an amination

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• of efforts to developing efficient thio/selenocyanation approaches [33][34][35][36][37][38][39][40][41]. Specifically, a plethora of synthetic strategies have been reported for the thiocyanation of heteroaromatic compounds including arenes, indoles, carbazoles, pyrroles, and imidazopyridines [42][43

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• nickel-catalyzed cross-coupling reactions with aryl halides to deliver the desired cross-coupled products. Interestingly, in absence of any xanthate, sec-butyl radicals underwent cross-coupling reactions with aryl halides to form sec-butyl arenes, whereas in the presence of xanthate, no undesired sec

• -butyl arenes were generated. This underpinned the formation of sec-butyl radicals in the system that rapidly reacted with O-benzyl xanthates before participating in the nickel-catalyzed cross-coupling reactions. Precatalyst [Ni(dtbbpy)(H2O)4]Cl2 (50) and photosensitizer [Ir(dF(CF3)ppy)2(bpy)]PF6 (49

• various hydrocarbons in good yield. Alcohols containing electron-deficient arenes delivered a comparably lower yield (i.e., 62b–d, 52–63%), probably because of the lower nucleophilicity of the alcohols. Halogen atoms present in the p-position of alcohols were tolerated well and provided a decent yield

Rhodium-catalyzed homo-coupling reaction of aryl Grignard reagents and its application for the synthesis of an integrin inhibitor

• Kazuyuki Sato,
• Satoki Teranishi,
• Atsushi Sakaue,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai,
• Hiroyuki Takeda,
• Tatsuo Kinashi and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 1341–1347, doi:10.3762/bjoc.20.118

• -bromoethyl)arenes or styrenes in this reaction. Unfortunately, we have not clarified the reason why a cross-coupling reaction did not proceed. At this stage, we speculate that the elimination rate of ethylene and reductive elimination rate of 3 might be fast in this reaction. Medicinal chemistry application

Phenotellurazine redox catalysts: elements of design for radical cross-dehydrogenative coupling reactions

• Alina Paffen,
• Christopher Cremer and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2024, 20, 1292–1297, doi:10.3762/bjoc.20.112

• in the structure, or else at different positions, in order to establish how their redox catalytic reactivity might be affected. Indeed, we learned recently that amino-arenes possess some level of redox catalytic activity by themselves, in the absence of a Te-center [34], and therefore wished to

Synthesis and optical properties of bis- and tris-alkynyl-2-trifluoromethylquinolines

• Stefan Jopp,
• Franziska Spruner von Mertz,
• Peter Ehlers,
• Alexander Villinger and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1246–1255, doi:10.3762/bjoc.20.107

• methyl groups and are known to protect from metabolic oxidation [16]. Fluorine-containing arenes are metabolically more stable as compared to non-fluorinated arenes and they show a higher lipophilicity. Known synthetic approaches towards 2-trifluoromethylquinolines include the cyclisation of anilines

Light on the sustainable preparation of aryl-cored dibromides

• Fabrizio Roncaglia,
• Alberto Ughetti,
• Nicola Porcelli,
• Biagio Anderlini,
• Andrea Severini and
• Luca Rigamonti

Beilstein J. Org. Chem. 2024, 20, 1076–1087, doi:10.3762/bjoc.20.95

• [46][47][48][49], which can be produced with high efficiency. The peroxide-bromide method appears to be especially suitable for obtaining aryl-cored dibromides, too. However, to the best of our knowledge, this option has been scarcely exploited, except for a few reports on some activated arenes [50

• aromatic cores are affected by minor, yet inevitable, bromination on the ring. This is the case of dialkyl-substituted arenes having o,p-activated positions (ortho with respect to one alkyl substituent and para with respect to another alkyl substituent). For instance, bromination of m-xylene (2, Figure 3

• reports of ring bromination by means of NBS or the peroxide-bromide method are also known, but mainly for highly activated arenes (phenols or anisoles, for instance) or for the synthesis of monobromides [49][50][61]. Continuing our investigation on the subject, the ring bromination of p-xylene (3, Figure

Auxiliary strategy for the general and practical synthesis of diaryliodonium(III) salts with diverse organocarboxylate counterions

• Naoki Miyamoto,
• Daichi Koseki,
• Kohei Sumida,
• Elghareeb E. Elboray,
• Naoko Takenaga,
• Ravi Kumar and
• Toshifumi Dohi

Beilstein J. Org. Chem. 2024, 20, 1020–1028, doi:10.3762/bjoc.20.90

• are versatile reagents that exhibit a range of reactions, both in the presence and absence of metal catalysts. In this study, we developed efficient synthetic methods for the preparation of aryl(TMP)iodonium(III) carboxylates, by reaction of (diacetoxyiodo)arenes or iodosoarenes with 1,3,5

• a cartridge filled with powdered oxone® for in situ generation of bis(trifluoroacetoxyiodo)arenes and their reaction with electron-rich arene or arylboronic acid [19] (Scheme 1B). Carboxylic acids, such as acetic acid and benzoic acid, characterized by substantial difference in pKa values when

• (TFE, Scheme 2B) [21]. Our group previously reported the synthesis of diaryliodonium(III) salts by combining hypervalent iodine(III) reagents with electron-rich arenes in fluoroalcohol solvents, such as TFE or 1,1,1,3,3,3-hexafluoro-2-propanol [21][22]. These solvents stabilize the cationic

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• -catalyzed annulative π-extension of 1,8-dibromonaphthalene for the preparation of fluoranthenes in a single operation has been investigated. With specific arenes such as fluorobenzenes, the Pd-catalyzed double functionalization of C–H bonds yields the desired fluoranthenes. The reaction proceeds via a

• tuned, or enables them to be linked to other useful units [1]. There are several synthetic routes to fluoranthene derivatives, but in most cases several steps are required [2][3][4][5]. Over the past two decades, the Pd-catalyzed C–H arylation of a wide variety of arenes has led to a revolution in the

• synthesis of polyaromatic compounds [6][7][8][9][10][11][12]. Since the seminal results of Fagnou et al. in 2006 on the Pd-catalyzed C–H arylation of polyfluorobenzenes [13][14][15][16], several groups have described conditions enabling the direct intermolecular Pd-catalyzed arylation of arenes [17]. In

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• oxyalkylation product 28. Li and co-workers described the activation of NHPI esters towards SET using a Lewis acid catalyst, allowing for the functionalization of styrene radical acceptors with nucleophiles that do not necessarily engage in hydrogen-bonding interactions, such as electron-rich (hetero)arenes [47

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• ultimate elimination of chalcogen fragments upon thermal activation, photoirradiation and electron exchange. Keywords: arenes; chalcogens; extrusion; fused-ring systems; precursor approach; Introduction π-Conjugated polycyclic compounds (π-CPCs), including polycyclic aromatic hydrocarbons and their