Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• reactivity pattern. However, analysis of the results obtained (Figure 1b and Table S1 in Supporting Information File 1) clearly suggests that, again, there is no universal correlation between reaction time and stereoselectivity. Although at high concentration (0.15 mol·L−1) an increase in the reaction time

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• doublet, t = triplet, q = quartet, dd = doublet of doublets, dt = doublet of triplets, m = multiplet), coupling constant in Hz, integration. Assignments were aided by homonuclear 1H,1H (COSY, TOCSY) and 1H,13C heteronuclear (HSQC, HMBC) two-dimensional correlation spectroscopies. 13C chemical shifts were

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations

• Laura Abella,
• Gerard Novell-Leruth,
• Josep M. Ricart,
• Josep M. Poblet and
• Antonio Rodríguez-Fortea

Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10

• calculations. The fullerene dimerization mechanism inside a SWCNT was also studied by density functional theory applied to periodic systems through VASP code [31]. The exchange-correlation functional used was PBE with the zero damping DFT-D3 method of Grimme et al. [16]. Inner electrons were replaced by PAW

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

• . Systematic studies on varying photon fluxes showed an almost linear increase of the hydrogen evolution rate with lower photon fluxes (see Figure 12b). Generally, three regimes can be differentiated for the correlation of the reaction rate with the photon flux [37][38][39][40][41][42]. At low photon fluxes

• photon flux density, c0 is the photocatalyst concentration, and kr is the recombination rate. The linear correlation between reaction rate and photon flux visible in Figure 12b indicates that the system is still in regime 1 and the hydrogen generation rate is limited by the available photon flux, even

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• constant (kMeOH = 2.1 mM−1 s−1) as 2b, the product of the poor Michael acceptor acrylamide in CHCl3. The results show no correlation of the rate constant with the electrophilicity parameter of the Michael acceptors. The low rate constant for the acrylonitrile reaction in chloroform suggests that the

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• with regard to the starting pose (Figure 4). However, the sulfated part of the GAG overlaps with its initial position. Additionally, the correlation between the ligand’s RMSD and MM/GBSA per frame was analyzed (Table 1). In all cases positive correlations between analyzed values was observed. However

• , in some cases this correlation was below 0.5. This is in agreement with the data described above, which showed that despite a significantly different binding pose, sometimes the GAG maintained a relatively strong binding to the protein. This is particularly true for ligand 3 of acidic fibroblast

• number of contacts differ for pulling out and pulling in processes (Table 3). For the dissociation, as expected the number of native contacts and H-bonds correlate very well with the MM/GBSA energies (Pearson correlation coefficients obtained for all frames of the trajectories are 0.81 and 0.76

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

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

• chemistry but also by on-surface chemistry. All these results, which are open for further development, confirm that biphenylene structures are very important synthetic units and will be used as tools for the synthesis of more complex structures in the future. The correlation between stability and Clar's

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

• observed during the 1st and 2nd DSC heating and cooling scans. However, glass transitions were detected for all the studied compounds. The glass transition temperatures (Tg) fall in the range between 63 and 93 °C (Figure 5b). A correlation between the glass transition temperature and the molecular weight

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

• (Supporting Information File 1, Figure S23). Surprisingly, no correlation between signals corresponding to the axle and macrocycle have been observed. This result could be explained by rapid movement of the macrocycle along the axle with no preferred position. However, formation of the rotaxane could be

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

• rearrangement that is known to proceed in 3-substituted 4-iminopyrimidine systems [40][45][46][47]. Our analysis of 1H, 13C NMR, and 2D NMR spectra (DMSO-d6 solution) of the prepared product confirmed its structure as compound 8. For example, the 1H,13C-HMBC spectrum showed correlation of the NH2 protons with

• decoupling, DEPT-135 experiments as well as HMQC, HMBC, and NOESY correlation techniques were used to aid in the assignment of 1H and 13C NMR signals. Elemental analyses (CHN) were performed using a Thermo Finnigan Flash EA1112 apparatus. High-resolution mass spectra (HRMS) were obtained using a Bruker

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

• [58]. Potential electrostatic maps and electron density surfaces were calculated with DFT method from the CIF files using TONTO, also implemented in Crystal Explorer [58]. Computational methods All calculations were done with the Gaussian 16 package [59] using the B3LYP exchange and correlation

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• ). We have previously noted a similar lack of correlation between bond length and bond dissociation energy in comparing the structures of 1c2 (Y = Fc; R = R' = H) and 1e2 (Y = cyclohexyl; R = R' = H) [14], and in comparing those of different organometallic dimers [22][46]. As noted in our previous work

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• disticha. The structures of compounds 1–7 were elucidated by extensive 1D and 2D NMR spectroscopic analyses, including 1D total correlation spectroscopy (TOCSY), HSQC, HMBC, double quantum-filtered (DQF)-COSY, heteronuclear two-bond correlation (H2BC), and HSQC-TOCSY experiments, as well as high-resolution

• (C-1′′), 103.3 (C-1′′′), and 111.9 (C-1′′′′). Because the complex overlap of the glycosyl group signals complicated the HSQC, HMBC, and DQF-COSY analyses, 1D total correlation spectroscopy (TOCSY), HSQC-TOCSY, and heteronuclear two-bond correlation (H2BC) experiments were also performed (Figure 2

• ) [14][15]. The HSQC-TOCSY spectrum showed two correlation series corresponding to two ᴅ-glucopyranoses (δC 62.5, 70.0, 77.5, 77.9, 85.0, 103.2 and δC 61.5, 69.3, 76.7, 82.9, 85.5, 104.5). The signal at δC 85.0 was assigned to C-2′ based on the H2BC correlation with the anomeric proton at δH 4.57 (d, J

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

• and SBE-β-CD are active on CHOL-poor membranes. The effects of β-CD derivatives obtained in this study present a good correlation with biological membranes studies: the methylated β-CD derivatives with high degree of substitution (RAMEB in our study) possess the strongest CHOL extraction capacity and

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• of the reaction to 75 °C, which afforded the best results (70%, Table 1, entry 13). When 0.2 equiv, 0.7 equiv, and 1 equiv of LiHMDS was used, a lower product yield of 58%, 50%, and 36%, respectively, was observed (Table 1, entries 14–16). This was surprising because there was no correlation between

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• ZnMe2 (entries 9 and 10). This difference can be ascribed to a less favorable homolytic substitution reaction of ZnMe2 in relation to its higher analogues and is in line with previous literature observations [11]. The configuration of the major diastereomer was determined by chemical correlation (Scheme

• reaction of dialkylzinc reagents with α,β-unsaturated carbonyl compounds. Enolate formation by zinc radical transfer (SH2 on dialkylzinc reagents). Preparation of α-(aminomethyl)acrylate 10. Reaction of α-(aminomethyl)acrylate 10 with Et2Zn in the presence of air. Chemical correlation to determine the

• –H bonds.a Optimization of the air-promoted 1,4-addition of dialkylzinc reagents onto N-(tert-butanesulfinyl) α-(aminomethyl)acrylates. Supporting Information Supporting Information File 94: General information, characterization data, chemical correlation, and copies of NMR spectra

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• doublet with coupling constants around 4.5 and 11 Hz [28][33]. The β-orientation of H-3 in compound 1 was further supported not only by the ROESY correlation observed between H-3 (δH 4.68, t, J = 2.8 Hz) and Me-29 (δH 0.95, s), but also by the fact that 3-epipachymic acid (3) and 3α,25S-3-O-malonyl-23

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• the correlation of H3-15/H2-6 (Figure 3), which results in ambiguity in the relative configuration assignment of 1. Thus, NMR chemical shift calculations and ECD calculations were used to confirm the relative and absolute configuration of 1. More specifically, NMR calculations were carried out at the

• ). Thus, the planar structure of 3 was assigned (Figure 1). Further analysis of the coupling constants of H-7 (JH-7, Ha-6 = 3.3 Hz and JH-7, Hb-6 = 2.8 Hz) and the ROESY correlation (Figure 3) of H3-15/Hb-6 allowed us to conclude that H3-15 and H-7 are in the opposite orientation. Thus, the relative

• configurations of chiral centers in 3 apart from C-11 were assigned. To determine the configuration of C-11 we performed NMR calculations. The results disclose that 3 has likely the configuration of (7R*,10R*,11S*)-3 based on the DP4+ probability analysis and the correlation coefficient. To clarify the absolute

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• correlation spectroscopy (COSY; Figure 3). The first spin system is part of a 2,3-substituted phenol moiety featuring proton signals at δH 7.15 (H-5), 6.70 (H-6) and 6.69 ppm (H-4; Table 1). Three aromatic carbon atoms could be assigned due to heteronuclear multiple bond correlation (HMBC) correlations from H

• position. An HMBC correlation from H-4 to the carbon atom at 32.7 ppm (C-7) allowed the linkage of the phenol moiety with an n-pentyl sidechain in meta position to the hydroxy group. The spin system of the latter includes proton resonances at δH 2.54 (H-7a), 2.62 (H-7b), 1.49 (H-8), 1.25 (H-9), 1.25 (H-10

• accordance with eight degrees of unsaturation. The NMR data for 4 is closely related with that of compound 3. The carbon atom at 184.9 ppm (C-15) possesses an HSQC correlation to a proton resonance at δH 9.98 (H-15), which is characteristic of an aldehyde function. This is in full accordance with the loss of

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• indicated that the compound possesses the same two pentasubstituted benzene rings, suggesting an axially symmetric structure. The methoxy group is situated at C-3, as determined by the HMBC correlation (Figure 2 and Figure S12 in Supporting Information File 1) of H3-11/C-3 (δC 154.1). The hydroxy group and

• -hydroxyflavan skeleton. The distinction in compound 4 is an additional methoxy group, which is connected to C-5' as supported by the HMBC correlation (Figure 2 and Figure S24 in Supporting Information File 1) of 5'-OCH3 (δH 3.85)/C-5' (δC 136.1). Two asymmetric carbon centers are present at C-2 and C-2″ in

• (δC 43.8), and H-12/C-10, C-11. The presence of a conjugated carboxylic acid was verified by the HMBC correlation of H2-2 to C-1 (δC 177.1). Concerning the geometry of 7, the ROESY correlation (Figure 2 and Figure S32 in Supporting Information File 1) of H-10/H2-12 disclosed that the ∆10,11

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• -unsaturated γ-lactone ring. The HMBC cross-peaks (Figure 2) from H-11 (δH 5.86) to C-10, C-12, and C-13, and from H-15 (δH 6.03) to C-12, C-13 and C-14 allowed the location of an extended conjugated π-system at C-11 and C-12. Moreover, the downfield shift of C-14 (δC 72.2) and the HMBC correlation between H3

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

• (RCysNi)L7 formed in the Michael addition reaction was confirmed using the NOESY spectrum. It is illustrated in Figure 1 for (oBrCysNi)L7 complex as the representative example. A correlation between the signal of the H-2 proton at the α-amino acid stereocenter with the signal of the ortho-protons of the

• new ligand and amino acids (glycine and dehydroalanine) will find their rightful place in the stereoselective synthesis of tailor-made amino acids (including oxidative transformations). Fragment of the NOESY spectrum of the ʟ-(oBrCysNi)L7 complex indicating the correlation between the H-2 and H-17,21

Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme

• Josipa Matić,
• Tana Tandarić,
• Marijana Radić Stojković,
• Filip Šupljika,
• Zrinka Karačić,
• Ana Tomašić Paić,
• Lucija Horvat,
• Robert Vianello and
• Lidija-Marija Tumir

Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40

• Scatchard equation [38] and Global Fit procedure [40]. Calculations mostly gave values of ratio n = 0.2 ± 0.05, but for easier comparison all Ka values were re-calculated for fixed n = 0.2. Values for Ka have satisfactory correlation coefficients (>0.98). In Scatchard equation values of association constant

Access to cyclopropanes with geminal trifluoromethyl and difluoromethylphosphonate groups

• Ita Hajdin,
• Romana Pajkert,
• Mira Keßler,
• Jianlin Han,
• Haibo Mei and
• Gerd-Volker Röschenthaler

Beilstein J. Org. Chem. 2023, 19, 541–549, doi:10.3762/bjoc.19.39

• stereochemistry of the main isomer, the 19F,1H-HOESY NMR spectrum of compound 6c was recorded. The spectrum shows direct correlation of one fluorine nucleus of the difluoromethyl phosphonate group with two cyclopropane protons at 1.75 and 2.91 ppm, respectively. Thus, it is conceivable that the major