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

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

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• , the fs-TA spectroscopy was not used to study their photophysical processes [47]. Femtosecond transient spectra of NI-PTZ-F-O were also studied (Figure 7c and 7d). The solubility of NI-PTZ-F-O in HEX is poor, which leads to a poor transient spectral signal (Figure S35c and S35d in Supporting

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• solubility of this complex in water. X-ray crystallography of the crystals showed a 1:1 complex of CO2 to α-CD with CO2 bound in the center of the wide, secondary rim of the α-CD cavity (Figure 2). Two of the hydroxymethyl side groups on the primary narrow rim are disordered. The disordering was modeled over

• water under a partial pressure of CO2. Using a literature value of the solubility of CO2 in water at 1 bar (34 mM) and Henrys law the more traditional aqueous binding constant Ka = [CD·CO2]/[CD][CO2] in molar terms could be calculated (Table 2). For α-cyclodextrin (1) a Kg of 0.18 bar−1 was obtained – a

• temperature dependence on solubility in water [16]. Therefore, binding of the unipolar CO2 molecule is expected to cause less water H-bond disruption in this host. Conclusion This work shows that CO2 is bound 1:1 by α-cyclodextrins and that the affinity can be improved with a smaller cavity and more

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• cleavage is probably influenced by glycan structure, solubility, and aggregation tendency [26]. Lastly, purification of the protected glycan upon cleavage could be affected by the presence or absence of a linker. L1 or L2 were conjugated to Merrifield resins with initial loadings of 0.5 mmol/g and 1.0 mmol

Asymmetric tandem conjugate addition and reaction with carbocations on acylimidazole Michael acceptors

• Brigita Mudráková,
• Renata Marcia de Figueiredo,
• Jean-Marc Campagne and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 881–888, doi:10.3762/bjoc.19.65

• solubility in water. Among exceptional properties belongs to easy post-transformation of acylimidazoles to common carbonyl analogs. These tunable properties allow the use of acylimidazoles in chemical biology research, which includes chemical synthesis of proteins/peptides, structure analysis, and functional

• earlier experience, we employed the tropylium ion with the more lipophilic bis(trifluoromethane)sulfinimide (NTf2) anion because of its better solubility in the applied organic solvents than the commercially available tetrafluoroborate (BF4) form [22][23][24]. The cyclic urea DMEU (1,3-dimethyl-2

A fluorescent probe for detection of Hg²⁺ ions constructed by tetramethyl cucurbit[6]uril and 1,2-bis(4-pyridyl)ethene

• Xiaoqian Chen,
• Naqin Yang,
• Yue Ma,
• Xinan Yang and
• Peihua Ma

Beilstein J. Org. Chem. 2023, 19, 864–872, doi:10.3762/bjoc.19.63

• change in fluorescence intensity can be used for the recognition of Cd2+ and Zn2+ ions [35]. The symmetric tetramethyl cucurbit[6]uril (TMeQ[6]) is one of the earliest characterized modified cucurbit[6]urils [36]. Compared with Q[6], tetramethyl cucurbit[6]uril (TMeQ[6]) has good solubility in water

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

• materials [1][2][3][4][5][6][7][8][9][10]. Due to its different characteristics such as basicity, stability, water solubility, small molecular size, and ability to form hydrogen bonds, pyridine continues to be a suitable moiety in organic synthesis. In addition, it has been observed that pyridine rings

Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous-flow conditions

• Masahiro Hosoya,
• Yusuke Saito and
• Yousuke Horiuchi

Beilstein J. Org. Chem. 2023, 19, 752–763, doi:10.3762/bjoc.19.55

• made it difficult to confirm the solubility due to the deep black color of the reaction mixture. This can increase the risk of clogging under continuous-flow conditions due to undissolved catalyst. From this reaction screening, we concluded that Table 1, entry 3 was the most suitable catalytic system

• improved greatly with the O2 balloon, and the reaction was completed in 20 min. The proposed catalytic cycle for aerobic oxidation is shown in Scheme 1 [40][46][47]. At room temperature, the solubility of O2 in the reaction solution is relatively high, and the catalytic cycle A, which is associated with

• the solubility of O2, is not the rate-determining step. Therefore, the reaction rates under open air and O2 balloon did not differ. On the other hand, increasing the temperature decreased the solubility of O2, which converted the catalytic cycle A to the rate-determining step at 60 °C. When the

Synthesis of imidazo[1,2-a]pyridine-containing peptidomimetics by tandem of Groebke–Blackburn–Bienaymé and Ugi reactions

• Oleksandr V. Kolomiiets,
• Alexander V. Tsygankov,
• Maryna N. Kornet,
• Aleksander A. Brazhko,
• Vladimir I. Musatov and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2023, 19, 727–735, doi:10.3762/bjoc.19.53

• 24 hours at room temperature in DMF with catalytic amounts of HClO4. The yield of compound 4a in this case was 76%. Then new heterocyclic acids were used as reagents for the Ugi four-component reaction. Due to the rather low solubility of the acids in methanol, it was necessary to increase the

• -chlorobenzaldehyde (5b), 4-methoxyaniline (6a) and tert-butyl isocyanide (3a). It should be especially noted that the solubility of compound 8a is very low (soluble in DMSO and N-methyl-2-pyrrolidone (NMP), slightly soluble in methanol, 1- and 2-propanol, acetone, DMF and insoluble in water, ethanol, acetonitrile

• imidazo[1,2-a]pyridine and peptidomimetic fragments it is better to use acids with a linker between the carboxyl group and aryl ring. This molecular fragment increases the solubility of the whole molecule, which leads to an improvement in the reactivity of the acids, whereas the reactivity of acids 8a and

Nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazines: access to pyrrolo[2,1-b][1,3]benzothiazoles

• Ekaterina A. Lystsova,
• Maksim V. Dmitriev,
• Andrey N. Maslivets and
• Ekaterina E. Khramtsova

Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46

• due to the solubility of the starting amine 11d and the corresponding products 12. In addition, in the reaction of APBTT 1a with mesidine (11b), we succeeded to isolate a side-product 14ab (Scheme 19). Similar side-products 14 were observed in all reactions of APBTTs 1 with arylamines 11 (UPLC–UV–MS

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• solution was increased to 10.4, the nanoparticles collapsed and aggregated (Figure 3d–f), which could be attributed to the poor solubility of the samples bearing neutral amino groups of CS-TPE under alkaline conditions, leading to the accumulation of molecular chains. The pH-responsive behavior of CS-TPE

• solubility of CS-TPS-10% after combining with TBTQ-C6. Furthermore, the complex reassembled into spherical nanoparticles when the pH of the solution was restored to 5.3 (Figure 6c). These results are consistent with the transmittance measurements, and similar phenomena were observed for the TBTQ-C6/CS-TPE-2

• improved water solubility of the supra-amphiphile due to the highly water-soluble behavior of TBTQ-C6 under alkaline conditions in its carboxyl anion form. As a result, the polymer chains were extended, releasing the entanglement and wrapping of the TPE fluorogens, thereby reducing the emission of the

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• . Unfortunately, with this catalyst, repeatability problems were detected (yield fluctuation of approximately 20%) which could be assigned to the low solubility of this catalyst in toluene. In order to overcome these problems, we synthesized triruthenium carbonyl complexes with phosphine ligand(s), namely

• (L1)3] (comp3) catalysts allowed to show, on the one hand, the absence of solubility problems, and to discover, on the other hand, that the presence of three L1 ligands (comp3) leads to a reaction rate clearly lower than that of a catalyst carrying one or two ligands (see p. S7 of Supporting

• compared to [Ru3(CO)12] at 200 °C (Table 1, entries 3 and 4). This can be attributed, as mentioned above, to the slightly faster reaction kinetics of the [Ru3(CO)12] catalyst compared to that of comp1. Nevertheless, the better solubility of comp1 in toluene allows to get around the problems of

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

• complex. Solubility of the t-Bu-containing ligand and its Schiff base complexes is increased, facilitating scaling-up the reaction procedure and isolation of the functionalized amino acid. Keywords: asymmetric synthesis; chiral auxiliaries; cysteine derivatives; Ni–Schiff base complexes; voltammetry

• the modification of the chiral auxiliaries as well as of the other fragments of the tridentate ligand have been made to improve stereocontrolling efficiency and to modify physicochemical properties of the template (such as solubility, lipophilicity, etc). Thus, various substituents (4,5-di-CH3 [21], 2

• stereoselectivity level. Additionally, Schiff base derivatives of L7 have a considerably higher solubility in acetonitrile as compared to the L4-based complexes (see Table 3 and Supporting Information File 1); this makes it easier to scale-up the synthesis (e.g., for the SN2 alkylations or nucleophilic addition