Direct synthesis of acyl fluorides from carboxylic acids using benzothiazolium reagents

• Lilian M. Maas,
• Alex Haswell,
• Rory Hughes and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2024, 20, 921–930, doi:10.3762/bjoc.20.82

• . Keywords: acyl fluorides; amides; benzothiazolium salts; carboxylic acids; deoxygenative reactions; Introduction Acyl fluorides are attracting much attention as versatile reagents for different applications in organic synthesis. In addition to their use as sources of fluoride ions, they are most commonly

• developed a series of 2-(fluoroalkylthio)benzothiazolium (BT-SRF) reagents for the deoxygenative transfer of SRF (RF = poly- or perfluoroalkyl) groups into organic molecules (Figure 1). In an initial report, the trifluoromethylthio-containing salt, BT-SCF3, was reacted with unactivated aliphatic alcohols to

• fluorides were also observed as by-products. Given the increasing interest in acyl fluorides in organic synthesis and the attractive features of BT-SRF salts as reagents for organofluorine chemistry, we considered whether optimisation of the reaction conditions could allow for the selective synthesis of

Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• -coupling; fluorescence; heterocycles; regioselectivity; Introduction Organic life is a complex interplay of many different building blocks. One of these building blocks is uracil. Discovered for the first time in 1901 by Alberto Ascoli, it is now known to be one of the four nucleobases of RNA [1]. It

• was complete. The reaction was neutralized with an HCl solution (1 M) and diluted with water (40 mL). The phases were separated, and the aqueous layer was extracted with dichloromethane (3 × 30 mL). The combined organic layers were dried over Na2SO4, concentrated under reduced pressure, and purified

• was complete. The reaction was neutralized with an HCl solution (1 M) and diluted with water (40 mL). The phases were separated, and the aqueous layer was extracted with dichloromethane (3 × 30 mL). The combined organic layers were dried over Na2SO4, concentrated under reduced pressure, and purified

Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins

• Ke Jiang,
• Cheng Pan,
• Limin Wang,
• Hao-Yang Wang and
• Jianwei Han

Beilstein J. Org. Chem. 2024, 20, 841–851, doi:10.3762/bjoc.20.76

• Technology, 130 Meilong Road, Shanghai 200237, P. R. China National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, The Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China 10.3762/bjoc.20.76 Abstract Cyclic annulation involving diaryliodonium

• . Keywords: annulation; arylocyclization; 3,4-benzocoumarin; diaryliodonium salts; naphthol; Introduction Diaryliodonium salts as electrophilic reagents have attracted significant attention in the field of organic synthesis owing to their efficiency and selectivity [1][2][3][4][5][6][7]. Particularly, they

Advancements in hydrochlorination of alkenes

• Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

• Daniel S. Muller Univ. Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226, 263 Avenue du Général Leclerc, F-35000 Rennes, France 10.3762/bjoc.20.72 Abstract The hydrochlorination of alkenes has been extensively studied in research and is commonly featured in organic

• focusing on hydrochlorination reactions. Firstly, an outstanding overview, including extensive research from the former Soviet Union, was reported in 1982 by Sergeev and co-workers [12]. Secondly, the chapter on “Addition of H-X Reagents to Alkenes and Alkynes” in comprehensive organic synthesis gives a

• by bubbling HCl gas, generated from NaCl and H2SO4, into dry DMPU. This yields a 14 M solution of HCl in DMPU, a concentration significantly higher than HCl solutions in other organic solvents. Further enhancement of the reaction was achieved through the addition of acetic acid. The reaction displays

Synthesis of new representatives of A₃B-type carboranylporphyrins based on meso-tetra(pentafluorophenyl)porphyrin transformations

• Victoria M. Alpatova,
• Evgeny G. Rys,
• Elena G. Kononova and
• Valentina A. Ol'shevskaya

Beilstein J. Org. Chem. 2024, 20, 767–776, doi:10.3762/bjoc.20.70

• has become one of the most popular route for the site-selective modification of cysteine residues in bioconjugation technology. We suppose that the maleimide group in porphyrin 11 is a useful target for thiol conjugation via Michael addition reactions [44]. This also concerns biotin-conjugated organic

Substrate specificity of a ketosynthase domain involved in bacillaene biosynthesis

• Zhiyong Yin and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2024, 20, 734–740, doi:10.3762/bjoc.20.67

• Zhiyong Yin Jeroen S. Dickschat Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany 10.3762/bjoc.20.67 Abstract An isotopic labelling method was developed to investigate substrate binding by ketosynthases, exemplified by the

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• increase the ratio of intramolecular nucleophilic attack, resulting in macrocyclic products via preorganization of substrate and enzyme in an active conformation [17][18]. Chemoenzymatic strategies, which merge practical enzymatic transformations with modern organic synthetic methods to increase the

SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

• Julien Borrel and
• Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

• Julien Borrel Jerome Waser Laboratory of Catalysis and Organic Synthesis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCSO, BCH 4306, 1015 Lausanne, Switzerland 10.3762/bjoc.20.64 Abstract We report the detailed background for the

• formation of 6 (Table 2, entry 4). In contrast, Ru(bpz)3(PF6)2 did not form the desired product probably due to its too high reduction potential compared to Ts-ABZ (3) (value reported for ABX: E1/2(ABX) = −0.43 V vs SCE) [52] (Table 2, entry 5). In general, organic dyes could not catalyze the transformation

New variochelins from soil-isolated Variovorax sp. H002

• Jabal Rahmat Haedar,
• Aya Yoshimura and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63

• -amino-2-methylpropanol in screw-capped vials. After flushing with nitrogen, the vials were sealed and heated at 180 °C for 18 hours. The reaction mixtures were then cooled down, resuspended in 3 mL of dichloromethane, and washed three times with 1 mL of water. The organic layer was dried with anhydrous

Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• Jan Bartacek Karel Chlumsky Jan Mrkvicka Lucie Palousova Milos Sedlak Pavel Drabina Institute of Organic Chemistry and Technology, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic 10.3762/bjoc.20.62 Abstract The new chiral ligands I–III

Regioselective quinazoline C2 modifications through the azide–tetrazole tautomeric equilibrium

• Dāgs Dāvis Līpiņš,
• Andris Jeminejs,
• Una Ušacka,
• Anatoly Mishnev,
• Māris Turks and
• Irina Novosjolova

Beilstein J. Org. Chem. 2024, 20, 675–683, doi:10.3762/bjoc.20.61

• , Latvia Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia 10.3762/bjoc.20.61 Abstract 2-Chloro-4-sulfonylquinazolines undergo functional group swap when treated with an azide nucleophile: 1) the azide replaces the sulfonyl group at the C4 position; 2) the intrinsic azide

Organic electron transport materials

• Joseph Cameron and
• Peter J. Skabara

Beilstein J. Org. Chem. 2024, 20, 672–674, doi:10.3762/bjoc.20.60

• Joseph Cameron Peter J. Skabara School of Chemistry, University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK 10.3762/bjoc.20.60 Keywords: acceptors; electron transport material; electron-deficient; n-type; organic semiconductors; There has been much interest in developing electron

• transport materials for organic semiconductor devices due to their potential to be applied in various technologies. For example, such materials can be used to improve charge balance in the emissive layer of an organic light-emitting diode, charge extraction in perovskite solar cells or used as the

• semiconductor layer of n-type organic field-effect transistors. Typically, an electron transport material should have a high electron mobility and a low-lying lowest unoccupied molecular orbital (LUMO) relative to vacuum. This is achieved by using electron-deficient units containing highly electronegative

Palladium-catalyzed three-component radical-polar crossover carboamination of 1,3-dienes or allenes with diazo esters and amines

• Geng-Xin Liu,
• Xiao-Ting Jie,
• Ge-Jun Niu,
• Li-Sheng Yang,
• Xing-Lin Li,
• Jian Luo and
• Wen-Hao Hu

Beilstein J. Org. Chem. 2024, 20, 661–671, doi:10.3762/bjoc.20.59

• . Multicomponent reactions (MCRs) by virtue of high efficiency for the construction of complex chemicals, have shown the superiority in high step and atom economy in organic synthesis [25][26][27]. Over the past two decades, our group and others have developed a transition-metal-catalyzed MCR strategy involving

• alkene followed by a nucleophilic addition, is unknown (Scheme 1b, bottom). The radical-polar crossover strategy has been steadily emerging in synthetic organic chemistry during the last few years [43][44][45][46]. This strategy allows complex chemicals to be assembled with high step economy that would

Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium

• Kairi Umeda,
• Naoaki Kurisawa,
• Ghulam Jeelani,
• Tomoyoshi Nozaki,
• Kiyotake Suenaga and
• Arihiro Iwasaki

Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57

• temperature for one day. The extract was filtered, and the combined filtrates were concentrated. The residue was partitioned between EtOAc (3 × 300 mL) and H2O (300 mL). The combined organic layers were concentrated, and the residue was partitioned between 90% aqueous MeOH (300 mL) and hexane (3 × 300 mL

Production of non-natural 5-methylorsellinate-derived meroterpenoids in Aspergillus oryzae

• Jia Tang,
• Yixiang Zhang and
• Yudai Matsuda

Beilstein J. Org. Chem. 2024, 20, 638–644, doi:10.3762/bjoc.20.56

• strong inosine 5-monophosphate dehydrogenase inhibitor [6]. The biosynthesis of fungal meroterpenoids has garnered interest in the organic chemistry field due to their structural complexity and associated intriguing enzymatic reactions and has thus been extensively researched for over a decade, providing

HPW-Catalyzed environmentally benign approach to imidazo[1,2-a]pyridines

• Luan A. Martinho and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2024, 20, 628–637, doi:10.3762/bjoc.20.55

• existing ones. Keywords: GBB-3CR; imidazo[1,2-a]pyridine; microwave; phosphotungstic acid; Introduction Imidazo[1,2-a]pyridine is a privileged structure that plays an important role in organic synthesis and in the pharmaceutical industry. This scaffold is present in drugs with several biological

• ·7H2O [36], and ZnCl2 [37], or organic acids such as p-toluenesulfonic acid (PTSA) [38], TFA [39], and AcOH [40], etc. Nonetheless, most of these acids have major drawbacks such as being expensive, dangerous, strong oxidizing, or even potentially explosive, with long reaction times being required. In

Chemical and biosynthetic potential of Penicillium shentong XL-F41

• Ran Zou,
• Xin Li,
• Xiaochen Chen,
• Yue-Wei Guo and
• Baofu Xu

Beilstein J. Org. Chem. 2024, 20, 597–606, doi:10.3762/bjoc.20.52

• hydroxamic acid 6 µM; sodium butyrate 6 µM). Extraction The mycelium was separated from the fermentation broth using a centrifuge and subsequently extracted with ethanol in a 1:1 ratio using ultrasound, three times for 20 minutes each. The combined organic solvents were dried with a rotary evaporator to

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Irina V. Dubonosova,
• Olga Yu. Karlutova,
• Oleg P. Demidov,
• Alexander D. Dubonosov and
• Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

• Physical and Organic Chemistry, Southern Federal University, Rostov-on-Don 344090, Russian Federation North Caucasus Federal University, Stavropol 355009, Russian Federation 10.3762/bjoc.20.47 Abstract A series of novel photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• , 2.28 mmol, 0.04 equiv), and the mixture was stirred at 80 °C for 3 h. Thereafter, the reaction mixture was cooled to room temperature, diluted with water, and extracted thoroughly with ethyl acetate. The combined organic layer was washed with brine, dried over Na2SO4, filtered, and concentrated under

• was added, followed by thorough extraction. The combined organic layer was dried over magnesium sulfate, filtered, and dried under reduced pressure. The remaining residue was purified via column chromatography (gradient ethyl acetate/hexane) to afford 6-bromo-5-(2-fluorophenyl)[1,3]thiazolo[4,5-b

• acetonitrile, formic acid was added, and the reaction mixture was stirred at room temperature for 2 h. The phases were separated via phase separator, and the organic layer was concentrated under reduced pressure. The remaining crude product was purified via column chromatography (gradient ethyl acetate/hexane

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

• solution. This concept was further developed with a bis-acridinium cyclophane [31] as a multiresponsive receptor for selective phase transfer. In organic media, this macrocyclic receptor presented an affinity for polyaromatic guests with strong selectivity for perylene. A reversible guest release was

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• and organic molecules [6]. Our results here are consistent, but the dynamics of mixed solvent systems are complex – water in DCM enhances rates, while water in MeOH nearly shuts them down. We presume these are consistent with the solubility effects proposed by Michon. In DCM, protic co-solvents were

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• Discussion For chemical investigation, the solvent EtOAc was used to extract the fermentation culture of the fungus P. boydii CS-793 to afford an organic extract. Isolation and purification of the crude extract with a combination of column chromatography (CC) by Lobar LiChroprep RP-18, silica gel, Sephadex

• concentrated under reduced pressure to give 123.6 g of an organic extract. The EtOAc extract was subjected to Si gel VLC (vacuum liquid chromatography) and fractionated using solvent mixtures of increasing polarity consisting of petroleum ether (PE) and EtOAc 20:1 to 1:1 and finally with CH2Cl2/MeOH 20:1 to 1

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

• Alexander S. Hampton,
• David R. W. Hodgson,
• Graham McDougald,
• Linhua Wang and
• Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

• difluoromethylene units. To meet the demands of synthetic chemists within the life science discovery and manufacturing arenas, many fluorination methods have been developed over the years to introduce difluoromethylene groups into organic systems. Approaches using nucleophilic fluorination include halogen exchange

• difluoromethylphenyl sulfoxide offer the possibility of transferring difluoromethylene groups directly into organic systems [19][20][21][22][23][24][25] and there is now a very extensive literature on carbon–carbon bond-forming reactions using these and other difluoromethylated building blocks [3][26][27][28][29][30

• ) gave only relatively low conversions to 2a and 3a. Other organic nitrogen bases were tested, and we found that quinuclidine (entries 8 and 9, Table 1) gave high conversion to difluorinated product 3a, with very little monofluorinated product 2a being observed. Suspensions of caesium carbonate or sodium

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• Nataliia V. Kirij Andrey A. Filatov Yurii L. Yagupolskii Sheng Peng Lee Sprague Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Academician Kukhar Str., 5, Kyiv-94, 02660, Ukraine The Chemours Company, Chemours Discovery Hub, Newark, DE 19713, United States 10.3762/bjoc

• on an industrial scale [2]. These hydrofluoroolefins belong to the newest 4th generation of fluorocarbon refrigerants and are promising compounds and starting materials. Due to this, interest in the use of (E)- and (Z)-butenes 1a,b as synthons in various organic transformations has recently grown

• . The reaction mixture gave a complex mixture, in which (E)-butene 3a was identified as a major component. Product 3a was removed from bulk diglyme in vacuum and after subsequent distillation it was isolated with a yield of 23%. As the isolation of the 2-dehydrobromination products from organic bases

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

• Eiichi Kayahara,
• Yoshiyuki Mizuhata and
• Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

• chemistry; Introduction Since the first bottom-up organic synthesis of cycloparaphenylenes (CPPs) [1][2][3][4][5][6][7], which are the carbon nanorings with the shortest possible structural constituent of armchair carbon nanotubes (CNTs), a new science of cyclic nanocarbons has emerged through synthesizing