Advancements in hydrochlorination of alkenes

• Daniel S. Müller

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

• hydrochlorination is operating within the rate of diffusion control (Figure 4). They also noted that the reaction was significantly slower at room temperature when compared to reactions carried out at 0 °C. However, reaction rates were exclusively reported at 0 and −45 °C, indicating an inverse temperature

Enhanced reactivity of Li⁺@C₆₀ toward thermal [2 + 2] cycloaddition by encapsulated Li⁺ Lewis acid

• Hiroshi Ueno,
• Yu Yamazaki,
• Hiroshi Okada,
• Fuminori Misaizu,
• Ken Kokubo and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2024, 20, 653–660, doi:10.3762/bjoc.20.58

• . The resulting solid was washed with diethyl ether and dissolved in dichloromethane. The desired monoadduct Li+@C60{(4-MeOC6H4)CH=CHMe} TFSI− (5a, 6.9 mg, 6.0 µmol, 71%) was afforded from the solution by vapor-diffusion recrystallization with diethyl ether. 1H NMR (400 MHz, CD2Cl2) δ 2.23 (d, J = 6.9

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

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

• Rattiya Janthanom,
• Yuta Kikuchi,
• Hiroki Kanto,
• Tomoyasu Hirose,
• Arisu Tahara,
• Takahiro Ishii,
• Arinthip Thamchaipenet and
• Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

• and fungi at 20 µg per disc in the paper disc diffusion method. Dihydroxybenzoic acid (DHBA) plays a role in anti-inflammatory, antihyperglycemic, antiapoptotic, and antioxidant processes [14]. 2,3-DHBA is found in nature and is produced by various plants (e.g., Gentiana rigerscense and Vinca minor

• paper disc diffusion assay at 20 µg on each paper disc and incubated at 37 °C for 24 h for M. luteus, B. subtilis, and E. coli; and 27 °C for 24 h for X. oryzae, C. albicans, and M. racemosus. Neighbor-joining tree based on 16S rRNA gene sequences between KR21-0001 and members of the genus

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• mg/mL was crystallized using hanging drop and vapor diffusion methods with a 2 µL drop in 1:1 ratio at 20 °C. Bipyramidal single crystals were obtained after one or two days in a solution containing 10–12% PEG Smear Medium, 0.1 M MES pH 6.5, 1× divalent (5 mM of CaCl2, MgCl2, CsCl2, CdCl2, NiCl2, and

Additive-controlled chemoselective inter-/intramolecular hydroamination via electrochemical PCET process

• Kazuhiro Okamoto,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2024, 20, 264–271, doi:10.3762/bjoc.20.27

• oxidation current can be considered as a decrease in the diffusion coefficient of the hydrogen bond complex; thus, we attempted to reproduce the CV pattern by computational simulation (Figures S1 and S2 in Supporting Information File 1) [16]. The results indicated that an excessively small diffusion

• coefficient (1/10- or 1/100-fold) is required to reproduce a CV pattern similar to that observed experimentally. Because the reported diffusion coefficient is only twice as small as that of the sole amide molecule [14], this simulated value is unrealistic, and we assumed that the diffusion coefficient did not

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• inert gas flow rate was increased from 25 to 75 mL min−1. This effect is attributed to an enhanced mass transfer of hydrogen from the photocatalyst to the gas phase. The relevant mass transport steps for hydrogen include the diffusion from the photocatalyst surface to the liquid bulk, transfer from the

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

• . Crystallography Crystals of CAAC·CS2 zwitterions 4a and 4c suitable for X-ray diffraction (XRD) analysis were grown by slow diffusion of cyclohexane in a THF solution at 6 °C. Their molecular structures are depicted in Figure 3. The orange-red needles of compound 4a belonged to the trigonal space group, while

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• , assuming that La@C2v-C82 and the monoadducts have the same absorption coefficients. X-ray crystallography Black crystalline rods of 3a were obtained using the liquid–liquid bilayer diffusion method with 3a in a CS2 solution and an n-hexane solution in a glass tube (⌀ = 7 mm) at room temperature. The SC-XRD

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• validated by 1H-DOSY NMR experiments (Figure 3, and Supporting Information File 1, Figure S26) indicating that the macrocycle and the axle diffuse as a whole with a diffusion coefficient of 4.2 × 10−10 m2/s. Conclusion In summary, we introduced herein a new synthetic strategy of [2]rotaxanes that combined

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

• -dissolving the powder in acetonitrile and layering on top of diethyl ether (Et2O). Slow diffusion of the antisolvent Et2O allowed the growth of magenta-colored crystals. Interestingly, two different sets of data could be solved, which is an indication that compound 1 has two polymorphs, 1a and 1b (Figure 2

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• . The enhanced and blue-shifted emission at the transition to the isotropic phase arise from the excited isolated molecules, where the exciton decays radiatively without diffusion. For the isolated molecules, the more localized π-orbital results in a higher energy emission state. The same effect was

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• conventional radical polymerization. Most free radicals have an extremely short lifetime due to a diffusion-controlled termination process between two free radicals. The inevitable termination between radicals makes the synthesis of well-defined polymers and co-polymers very difficult. In addition, polymers

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• , we first re-assessed the various extracts of the A. mexicana plant parts against this same panel, as our original study had only focused on the plant’s activities against six representative microbes [9]. Activities were assessed through a Kirby–Bauer disc-diffusion assay, measuring zones of

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

• isomeric mixture of 4BGIPN. This is expectedly higher than the analogous Tg of 176 °C for the 4CzIPN material [13] due to a lower molecular mass of the latter (Figure S1, Supporting Information File 1). Single crystals for X-ray diffraction study were obtained by slow layer diffusion of hexanes into

• ppm; Anal. calcd. for C60H32N14 (948.29): C, 75.94; H, 3.40; N, 20.66; found: C, 75.59; H, 3.54; N, 20.28; HRESIMS m/z: [M + Na]+ calcd. for C60H32N14Na, 971.2827; found, 971.2854. X-ray crystallography Crystals suitable for X-ray diffraction study were obtained by slow layer diffusion of hexanes

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

• a two-photon process. DBU was found to quench the steady-state fluorescence of *PC1 with a quenching rate constant two orders of magnitude smaller than the diffusion rate constant in DMSO at 298 K and one order of magnitude greater under the borylation reaction conditions (i.e., 0.20 M DBU) than the

• obtained by transient absorption spectroscopy with femtosecond pulsed laser excitation and were 2–3 orders of magnitude greater (e.g., keT (*PC1•−) = 6.8 × 1010 s−1) than the diffusion rate in DMSO (kdiff = 4.0 × 108 s−1 of 0.12 M 1d) confirming a preassociation of PC1•− and the substrate prior to PET

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

• the C=N bond), diffusion controlled (the slope of the ln ipc vs ln v dependence is 0.48), and reversible; the direct and reverse peak separation value was 57 mV at 100 mV/s, and Ia/Ic peak current ratio was close to unity. This means that the radical anion of (GlyNi)L7 is stable, at least in the

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• antibacterial or antifungal activities were observed [55]. Ponnapalli and co-workers tested in an agar diffusion assay the isolated compounds corniculatolide A (4), 11-O-methylcorniculatolide A (5), 12-hydroxy-11-O-methylcorniculatolide A (6), isocorniculatolide A (7), and 11-O-methylisocorniculatolide A (8

Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements

• Robert N. Goldberg,
• Robert T. Giessmann,
• Peter J. Halling,
• Carsten Kettner and
• Hans V. Westerhoff

Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26

• . Concentration expressed as mol∙dm−3 has important advantages when dealing with transport properties (e.g., diffusion coefficient and transport number). In this document the word “concentration” is used with the understanding that “molality” or mole fraction could also have been used. The reaction equation and

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• parameter of the release curve) value is a criterion used to illuminate the release from a polymeric matrix. “β” ≤ 0.75 indicates Fickian diffusion, while 0.75 < “β” < 1 indicates Fickian diffusion and controlled release combination [35]. The “β” value for the Weibull model was calculated as 0.396 and 0.434

• for the 6-O-capro-β-CD and CS-(6-O-capro-β-CD) nanoparticle formulations, respectively. According to the Weibull model, CPT release kinetics from nanoparticles were found to be compatible with Fickian diffusion in SGF medium [36]. In the model-independent principal evaluation of in vitro release

• profiles, this was considered as the rapid/burst and initial release of the drug adsorbed on the nanoparticle surface or encapsulated in the nanoparticle material matrix. It has been confirmed by mathematical modeling that the release is based on diffusion. This indicates the release of the CPT, which is

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• yield compound 1 (0.7 mg). Nostochopcerol (1): [α]D22.4 −5.9 (c 0.01, MeOH); UV (MeOH) λmax, nm (log ε): 200 (1.7); HRMS–ESIMS (m/z): [M + Na]+ calcd for C19H34NaO4+, 349.2349; found, 349.2348; IR (ATR) νmax: 3350, 2921, 2852, 1601, 1457, 1195, 1103, 1015, 875, 696 cm−1. Paper disk-agar diffusion method

• According to a procedure described in [6], the antimicrobial potency of chromatographic fractions was evaluated by a paper disk-agar diffusion method. Fractions at each purification stage were diluted to the same concentration with MeOH, and 10 μL aliquots were impregnated into 6 mm-diameter paper disks

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

• Bilge Banu Yagci,
• Selin Ezgi Donmez,
• Onur Şahin and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

• ]. In the present work, the α-methylene-γ-lactam products 19 were in most cases isolated as oils after column chromatography. Fortunately, lactam product 19l turned out to be a solid, and high-quality crystals could be obtained via slow vapor diffusion of pentane into its CH2Cl2 solution. Single-crystal

Modern flow chemistry – prospect and advantage

• Philipp Heretsch

Beilstein J. Org. Chem. 2023, 19, 33–35, doi:10.3762/bjoc.19.3

• scalability, and higher sustainability are the most prevalent ones. To provide examples and explanation for these claims, “flash chemistry”, a term coined by late Yoshida [4] for reactions at the diffusion limit, i.e., reactions completed within milliseconds with proper mixing, showcases the fast heat- and

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

• diffusion coefficient by binding with a high-molecular-weight host serves as a reliable indicator for the determination of binding parameters in a case if, for example, no alternation of chemical shifts is observed on the NMR spectrum. The diffusion coefficient can be estimated by a DOSY experiment [37]. In

• our case, a gradual, steady decline of tetracene's diffusion coefficient was detected by titration with 4, but it exceeded the measurement error only at the maximum concentration of the CD. Thus, this method discovers a poor supramolecular interaction where a reliable determination of the binding

Synthesis, optical and electrochemical properties of (D–π)₂-type and (D–π)₂Ph-type fluorescent dyes

• Kosuke Takemura,
• Kazuki Ohira,
• Taiki Higashino,
• Keiichi Imato and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

• evaluated to be 0.28 V for OTK-2 and 0.35 V for OTT-2. Therefore, the E1/2ox for OTK-2 with the (D–π)2Ph-type structure is cathodically shifted by 0.07 V, compared with that for OTT-2 with the (D–π)2-type structure. Furthermore, we investigated the diffusion-controlled process form CV at different scan

• negligible change during 20 cycles at a scan rate of 100 mV s−1, indicating diffusion control and good reversibility of the oxidation process (Figures S2b,c and S3b,c, Supporting Information File 1). The highest occupied molecular orbital (HOMO) energy level versus vacuum level was estimated from the E1/2ox