Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• because of their low water solubility. The styrylpyridine derivatives 2a–g were irradiated in oxygen-saturated solutions in MeCN, H2O, MeOH, or MeCN/H2O with a high-pressure Hg lamp (λ > 220 nm), and the course of the photocyclization reaction was monitored by absorption spectroscopy (Figure 2). In

• S6A). Because of the low water solubility of the styrylpyridine derivatives 2a–g, solvent mixtures of MeCN/H2O or pure MeCN were used for the preparative photocyclization reactions (Scheme 3, cf. Supporting Information File 1, Figure S2C,D) to provide sufficient solubility of the substrates, as well

• low solubility of compound 2c in aqueous solutions, the former could not be irradiated in situ in the presence of DNA. Photoinduced DNA damage In first orienting experiments, the photoinduced DNA damage by benzo[c]quinolizinium derivatives was examined exemplarily with ligand 3f and plasmid DNA pBR322

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• ) Pd2dba2, P(t-Bu)3, CuI, THF, Et3N, rt. Synthesis of acetylenic scaffolds with IF as central core. *Not fully characterized due to poor solubility. Conditions: (a) Pd(PPh3)2Cl2, CuI, THF, Et3N, rt. Reduction of IF dione 1 to dihydro-IF 29. UV–vis absorption data of compounds in PhMe or CH2Cl2 at 25 °C

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• -solubilities. It is noteworthy that an AA derivative featuring three nonionic –O(CH2CH2O)2CH3 side-chains on the phenylene spacer is insoluble in water (see Figure S45 in Supporting Information File 1), emphasizing the importance of the hydrophilic pyridinium core for the observed water-solubility. Formation

• the employed PA-R side-chain, likely due to the difference in water-solubility of the corresponding amphiphiles. The efficiency was found to be in the order of PA-Im > PA-OH > PA-OCH3 >> PA-CH3, as judged by the guest absorbance at 525 nm (Figure 4c). Importantly, PA-OCH3, PA-OH, and PA-Im displayed

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• rapid and comparatively easy deduction of structural features with the only requirement being the molecule's solubility in deuterated solvents. Therefore, NMR spectroscopy is of ubiquitous presence in many disciplines today. At the same time, with the high throughput analysis of samples that has been a

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• solvents screened, 1,4-dioxane was found the best solvent in terms of yield of the target product, solubility of the reagents, and ease of separation of the product. Thus, the optimal conditions found were reacting amidine 1 with azide 2 in the presence of DBU in a 1:1:1 ratio in 1,4-dioxane at room

• of the substituents in azides 2 was observed. We assume the higher yield of pyrimidine containing triazoles 3a–k by their lower solubility in 1,4-dioxane compared with the solubility of azole containing compounds 3l–s in both 1,4-dioxane and ethanol. With regard to the scope of diaminoacrylonitriles

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• this way, the hydration product was not obtained. In addition to the different reactivity, due to the presence or not of chlorine in the para position of the phenyl group, the different physical state (liquid for 1m vs solid for 1n) and the possible different solubility in BMIm-BF4 at room temperature

• . Therefore, while confirming the presence of the adduct, we could not quantify it. The next choice was DBU (1,8-diazabicyclo[5,4,0]undec-7-ene). The DBU-BF3 adduct is reported to be very stable in water and in air and not subjected to hydrolysis [115]. The DBU solubility in BMIm-BF4 was confirmed by NMR

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• can be attributed to Clar's rule, which considers the increasing number of non-sextet rings throughout the acene series as a contributing factor (Figure 1) [5][6]. Numerous approaches have been developed to address the challenges arising from the instability and solubility issues encountered in acenes

• successfully obtained in 30% yield. In the final step, the target POA-type structure containing naphthazarin 69 was synthesized by aromatization under acidic conditions. The attempts to conduct complexation experiments using BF3·OEt2 to obtain a stable BF2 complex were unsuccessful, primarily due to solubility

• complexation step to isolate stable BF2 complex of 69, likely attributable to solubility issues encountered with substrate 69, prevented the incorporation of the acene backbone into the structure. Consequently, the anticipated red-shift in the absorption spectrum could not be observed as expected. Boron-doped

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• fullerenes act as anion–π catalyst without additional activating groups, usually a tethered base to inject a negative charge into the substrate directly on top of the catalytic π surface [69]. The tert-butyl esters in Bingel fullerene 31 serve only to improve solubility and are not expected to participate in

• were not fruitful, mostly due to poor solubility. Anion–π catalysis on carbon nanotubes With fullerenes confirmed as privileged scaffold for induced anion–π catalysis but higher oligomers inaccessible [12][67][80], the obvious next move was to switch to carbon nanotubes. Compared to the sixty free

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• compounds 6–9 were confirmed by the spectral data and elemental analyses. Remarkably, despite a highly hindered structure, compound 9 exhibits good solubility in non-polar solvents. Photophysical properties The electronic structures of compounds 6–9 in the ground and excited states were investigated by

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• , the proposed diazo reagent 4 possesses several drawbacks, primarily, insufficient stability during storage and comparatively low solubility in non-polar solvents, as well as complications when isolating it in a pure form. This study focuses on the development of a "diazo" technique to incorporate a

• simplified the process of isolating compound 5, as compared to the prior publication [26], and notably increased its stability. Furthermore, the solubility of the new diazo reagent in non-polar solvents, particularly DCM, was significantly improved, leading to a beneficial impact on the course of Rh(II

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• the other components of the reaction mixture. The lipophilic O-alkylated gallic acid unit increases the solubility of the organocatalyst in less polar solvents, such as DCM or toluene but leads to the precipitation of the organocatalyst in polar solvents, including MeOH or MeCN. As a result, the

• addition of trans-β-nitrostyrene (12) and acetylacetone (13). Choosing the best solvent for the reaction is crucial, thus, solubility tests were carried out (Table 1). Since homogeneous catalysts usually exhibit higher activity and selectivity than their heterogeneous counterparts [27], our aim was to

• carry out the catalytic reaction homogeneously. The solubility of the lipophilic catalyst 2 was investigated in ten solvents with low polarity, including a new, bio-based polar aprotic solvent, MeSesamol [33]. The catalyst’s precipitation – which is necessary for its recycling – was tested by adding a

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• complex obtainable via a straightforward synthesis, with improved solubility, concerning our previous Co(II) complexes [21]. Thus, the new Co(II) complex bears two 1-benzyl-4-(quinolin-2-yl)-1H-1,2,3-triazole (BzQuTr) units, that were obtained through a copper-catalyzed alkyne–azide cycloaddition (CuAAC

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• with a noticeable increase in the macrocycle yield up to 41% (Table 1, entries 20 and 21). The extremely poor solubility of product 5 in most organic solvents allowed to purify it from all admixtures, including byproduct 6, by a single crystallization from boiling DMF. Thus, pure product 5 was prepared

• , intermediates A, C, D, and hydrazine. Figure 1 shows that the hydrazine-promoted transformation of pyrazolopyrimidine 8 into macrocycle 5 in MeOH is a thermodynamically favorable process. Moreover, the extremely low solubility of macrocycle 5 makes the dimerization of 8 even more preferable. It is noteworthy

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• species (ROS) in vitro, which may be another mechanism through which the compound exerts its protective effects in the brain. From a drug development perspective, however, INHHQ has some pharmacological limitations, such as low solubility and certain susceptibility to hydrolysis in a water-rich medium

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• , wherein researchers substituted alkoxy chains to enhance solubility and difluoro groups to lower the highest occupied molecular orbital (HOMO) energy level. Qx-derived polymer acceptors have witnessed significant progress in recent years, driven by a contextual understanding of the major issues hindering

• morphology on Qx26 and Qx27, employing indacenodithiophene, Qx and rhodanine as donor, acceptor and end group, respectively. The incorporation of specific side chains facilitated improved thermal stability, solubility, and broad absorption spectra (300–750 nm), narrow bandgaps (1.68–1.74 eV) and PCEs in the

• electronics [51]. Hasegawa and colleagues focused on achieving air-stable n-channel conduction by synthesizing thiadiazole-fused quinoxalineimide derivatives, Qx47–Qx49. The team optimized the molecular packing and solubility by incorporating solubilizing N-substituted alkyl chains. The resulting molecules

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• the previously reported cyanated N-annulated perylene diimide (CN-PDIN-H), the N-position was functionalized with a benzyl and pentafluorobenzyl group to make CN-PDIN-B and CN-PDIN-FB, respectively. The materials exhibit solubility in the green solvent, ethyl acetate, and thus were processed into thin

• -PDIN-H scaffold was functionalized with a benzyl (CN-PDIN-B) or pentafluorobenzyl group (CN-PDIN-FB). Addition of the benzyl and pentafluorobenzyl groups was to enhance solubility in green solvents, while nitrile functionalization was done to further stabilize the LUMO of the compounds. These materials

• cast from a solution at a concentration of 1 mg/mL in ethyl acetate, where a concentration of 1 mg/mL was used due to CN-PDIN-FB exhibiting a maximum solubility of 1.2 mg/mL (see below). The PDIN-B film has the highest absorbance of 0.037 at its λmax of 535 nm for the 0 → 0 transition and an onset of

Cyclodextrins permeabilize DPPC liposome membranes: a focus on cholesterol content, cyclodextrin type, and concentration

• Ghenwa Nasr,
• Hélène Greige-Gerges,
• Sophie Fourmentin,
• Abdelhamid Elaissari and
• Nathalie Khreich

Beilstein J. Org. Chem. 2023, 19, 1570–1579, doi:10.3762/bjoc.19.115

• internal cavity and a hydrophilic outer surface [1]. The common CDs are the native α-CD, β-CD, and γ-CD consisting of 6, 7, and 8 ᴅ-glucopyranose units, respectively. Due to their limited water solubility (especially β-CD), native CDs can be chemically or enzymatically modified (by e.g., alkylation

• , arylation, hydroxypropylation, amination, etherification, etc.) giving rise to synthetic CD derivatives with greater water solubility [2]. Thanks to their unique structure, CDs can offer exclusive advantages by allowing the entrapment of lipophilic molecules inside their inner cavities. This inclusion

• improves the chemical stability and aqueous solubility of the guest molecule and results in most of the cases in the formation of a water-soluble CD–guest complex [3]. Being recognized as non-toxic, biodegradable, and sustainable carriers, CDs have attracted wide interest as potential carriers in different

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

• (cavity) and the other directional due to hydrogen bonds (hydroxy groups), leads to the formation of these complexes. Results and Discussion The addition of two equivalents of sec-amines to an ethanol solution of R[4]A results in the formation of a crystalline precipitate with limited solubility in non

• chains, complexes with 1:2 stoichiometry are formed. This stoichiometry is justified by calculations of the acidity of protons of hydroxy groups in the R[4]A molecule. These complexes are highly ionic because of their very low solubility in non-polar solvents. Complexes with higher stoichiometry are not

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• pyrazolone derivatives with N-thiophthalimides catalyzed by 1 mol % of chiral iminophosphorane organocatalyst was carried out under mild conditions [103]. Solvent control in the procedure can affect the yield of products due to the solubility of the catalysts. Various solvents, such as acetone, ethyl acetate

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• studied. Several 2-methylisoborneol synthases have a proline-rich N-terminal domain of unknown function. The results presented here demonstrate that this domain leads to a reduced enzyme activity, in addition to its ability to increase long-term solubility of the protein. Furthermore, the substrate scope

• combination of domains A and B resulted in a moderately enhanced production of 1 (137 ± 6%). In other words, domain A, especially if it is covalently bound to domain B, serves as a gatekeeper that limits the production of 1 by 2MIBS. Furthermore, a difference was observed in the long-term solubility in the

• elution buffer used for protein purification through Ni2+-NTA affinity chromatography. While domain B alone showed a substantial enzyme precipitation after 12 h at 4 °C, full length 2MIBS did not (Figure 1B), suggesting that the A domain increases enzyme solubility and long-term stability. This effect

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• solubility of the salt. 1.2 Analogues of PAF with modification on sn-1 position PAF is characterized by a C16 or C18 saturated lipid chain at the sn-1 position. A first analogue, reported by Hirth et al. in 1983, consisted in replacing this saturated lipid chains by the mono-unsaturated oleyl ((Z)-octadec-9

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• deprotonation the latter with sodium hydride base. The compound shows poor solubility in most common organic solvents with moderate solubility in dichloromethane, 1,2-dichlorobenzene and dimethyl sulfoxide (DMSO). Compound 4BGIPN was characterized by high-resolution mass spectrometry (HRMS), elemental analysis

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• considered: solubility in the chosen solvent, absorption spectrum, oxidation potential, and the reversibility of the sacrificial donor oxidation. As the sacrificial donor is a reactant in the photoreduction reaction of carbon dioxide, it needs to be highly soluble in the solvent used. It also needs to have a

• . TEMPO and ferrocene derivatives are used to store positive charge in RFB catholytes [59][63]. Both parent compounds undergo reversible one-electron oxidation and re-reduction but had to be modified to improve their solubility. TEMPTMA and both ferrocene derivatives have one or more ammonium groups added

• to the core TEMPO or ferrocene charge-carrying moiety. This both increases the solubility of the species and the oxidation potential in aqueous media. TEMPOL uses an alcohol group to the same effect. Redox couples for RFB catholytes are optimized for increasing the oxidation which decreases their

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• include nucleophile σ-hole selectivity, and how ylide structural modifications and intramolecular halogen bonding (e.g., the ortho-effect) can improve ylide stability or solubility, and alter reaction outcomes. Keywords: electron donor–acceptor complex; halogen bonding; σ-holes; iodonium ylides; ortho

• potential to alter the physical properties (e.g., stability, solubility, UV–vis absorption) of an ylide, as well as bias a Lewis base’s σ-hole selectivity through σ-hole blocking, which represent emerging avenues for tuning an ylide’s reactivity and improving its reaction outcomes. Review 1 Halogen bonding

• -substituted iodoarene-derived iodonium ylides for improved solubility and stability [5][6][141]. ortho-Iodoanisole-derived ylide 39 was subject to a rhodium-catalyzed cyclopropanation reaction with styrene, and the results were compared with Charette’s 2009 work on 31 (Scheme 15) [142]. While both ylides were

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• retardants [14]. Sulfoxides are prominent pharmaceutical ingredients, while phosphine oxides improve solubility of corresponding compounds [15] and have applications in catalysis and materials science [16]. Selenoxides find use as oxygen transfer agents and donor ligands in metal catalysis and organic