Synthesis and characterization of water-soluble C₆₀–peptide conjugates

• Yue Ma,
• Lorenzo Persi and
• Yoko Yamakoshi

Beilstein J. Org. Chem. 2024, 20, 777–786, doi:10.3762/bjoc.20.71

• . Purple arrows in (b) indicate the split peaks. The 1H NMR spectrum of purified 5b was measured in D2O with 2% NaOD (Figure S12, Supporting Information File 1). 13C NMR analysis of the same sample was not possible due to the high ionic strength of the solution. NMR characterization was performed using a

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

• maintained in DMSO-d6 solution. It is worth noting that the presence of the electron-withdrawing nitro substituent in hdz-NO2 makes the interaction stronger. An IR spectroscopy study, which was supported by computational calculations, as well as a complete NMR characterization of both compounds, align with

• structures (Figure S4), experimental and calculated geometric parameters (Tables S1 and S2) and vibrational assignments (Tables S3 and S4), 13C, COSY, HMBC and HSQC spectra (Figures S5–S12) and the full NMR characterization (Table S5) for both hydrazones reported herein. Hydrolytic stability of hdz-NO2 at pH

Selective recognition of ATP by multivalent nano-assemblies of bisimidazolium amphiphiles through “turn-on” fluorescence response

• Rakesh Biswas,
• Surya Ghosh,
• Shubhra Kanti Bhaumik and
• Supratim Banerjee

Beilstein J. Org. Chem. 2020, 16, 2728–2738, doi:10.3762/bjoc.16.223

• , water/DMSO, 99.5:0.5, pH 7.4). Supporting Information Supporting Information File 382: Synthetic procedures, additional spectroscopic, microscopic and dynamic light scattering data (figures and tables) and NMR characterization. Funding IISER Kolkata and INSPIRE are acknowledged for research

Muyocopronones A and B: azaphilones from the endophytic fungus Muyocopron laterale

• Ken-ichi Nakashima,
• Junko Tomida,
• Tomoe Tsuboi,
• Yoshiaki Kawamura and
• Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 2100–2107, doi:10.3762/bjoc.16.177

• formula determined by HRESIMS, the 2,4-dimethyl-3-hydroxyhexanoate side chain was finally predicted to be connected to the remaining oxygenated carbon (C-7) of the azaphilone core. During their investigation into the structural determination of (−)-SCH 64874, Tokuyama et al. reported the synthesis and NMR

• characterization of the four possible diastereomers of the β-hydroxycarboxylic acid side chain [20]. Based on the obtained NMR data, the relative structure of the side chain of 1 was determined to adopt the (2′R*,3′R*,4′S*) configuration, as determined by the chemical shifts and the coupling constants between H-2

Polarity effects in 4-fluoro- and 4-(trifluoromethyl)prolines

• Vladimir Kubyshkin

Beilstein J. Org. Chem. 2020, 16, 1837–1852, doi:10.3762/bjoc.16.151

• Information File 134: Data on acid–base transition and amide bond isomerism and NMR characterization of compounds 1–7. Funding The author would like to acknowledge Canadian federal government for funding the research chair for chemical synthetic biology (lead Dr. Budisa) at the University of Manitoba.

4-Hydroxy-3-methyl-2(1H)-quinolone, originally discovered from a Brassicaceae plant, produced by a soil bacterium of the genus Burkholderia sp.: determination of a preferred tautomer and antioxidant activity

• Dandan Li,
• Naoya Oku,
• Yukiko Shinozaki,
• Yoichi Kurokawa and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1489–1494, doi:10.3762/bjoc.16.124

• compounds and a synthetic preparation of 1, allowed its first full NMR characterization and identification of 2-quinolone but not 2-quinolinol (2) as the preferred tautomer for this heterocyclic system. While the metal-chelating activity was negligible, compound 1 at 10 μM, a concentration lower than that

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

• Esteban P. Urriolabeitia,
• Pablo Sánchez,
• Alexandra Pop,
• Cristian Silvestru,
• Eduardo Laga,
• Ana I. Jiménez and
• Carlos Cativiela

Beilstein J. Org. Chem. 2020, 16, 1111–1123, doi:10.3762/bjoc.16.98

• that steric hindrance plays a role during the reaction. Oxazolones 2a–j contain two exocyclic C=C bonds in their skeleton and these can, in principle, have different conformations. The NMR characterization of 2a–j showed that they are obtained as single isomers. The oxazolone exocyclic C=C bond has the

• absorption maxima for complexes 3 located in the range of 454–467 nm. In this case the use of blue light (465 nm) is optimal for their irradiation, because the irradiation wavelength matches the maximum absorption. NMR characterization of complexes 4 showed that all compounds were obtained as a single

Direct borylation of terrylene and quaterrylene

• Haruka Kano,
• Keiji Uehara,
• Kyohei Matsuo,
• Hironobu Hayashi,
• Hiroko Yamada and
• Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

• with AlCl3 reproducibly provided a pure terrylene [8]. Scholl reaction using a superacid catalyst in combination with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant provides a scalable preparation of quaterrylene [9], but unfortunately the low solubility prevents 1H NMR characterization

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

• Vuyisa Mzozoyana,
• Fanie R. van Heerden and
• Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

• for coumarin 6 is solvent independent. A literature report of the NMR characterization of a structurally similar 7-hydroxycoumarin performed in DMSO-d6 has the signal for H5 reported as a singlet [44]. Since coumarins 6 and 5 have similar structure, the only difference is at position seven, 6 has a

Arylisoquinoline-derived organoboron dyes with a triaryl skeleton show dual fluorescence

• Vânia F. Pais,
• Tristan Neumann,
• Ignacio Vayá,
• M. Consuelo Jiménez,
• Abel Ros and
• Uwe Pischel

Beilstein J. Org. Chem. 2019, 15, 2612–2622, doi:10.3762/bjoc.15.254

• described and the NMR characterization data of the dyes are given. General procedure for the Ir-catalyzed borylation – synthesis of the dyes 16–19 Following the described procedure [42], a dried Schlenk tube was loaded with the substrate (12–15) and B2Pin2 (1 equiv). After three vacuum–argon cycles, 1 mL

Different reactivity of phosphorylallenes under the action of Brønsted or Lewis acids: a crucial role of involvement of the P=O group in intra- or intermolecular interactions at the formation of cationic intermediates

• Stanislav V. Lozovskiy,
• Alexander Yu. Ivanov and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2019, 15, 1491–1504, doi:10.3762/bjoc.15.151

• -1,2-oxaphosphol-2-ium ions. The progenitor of the oxaphospholium ion family, 2,2-dichloro-5,5-dimethyl-1,2-oxaphosphol-2-ium, was postulated for the first time in 1978 [12]. We have recently reported on the generation, NMR characterization and reactions of oxaphospholium ions bearing phenyl or phenoxy

Efficient synthesis of 4-substituted-ortho-phthalaldehyde analogues: toward the emergence of new building blocks

• Clémence Moitessier,
• Ahmad Rifai,
• Pierre-Edouard Danjou,
• Isabelle Mallard and
• Francine Cazier-Dennin

Beilstein J. Org. Chem. 2019, 15, 721–726, doi:10.3762/bjoc.15.67

• Information File 340: Additional protocol and NMR characterization. Acknowledgements Pole Metropolitain Cote d’Opale (PMCO) is gratefully acknowledged for financial support.

Polyaminoazide mixtures for the synthesis of pH-responsive calixarene nanosponges

• Antonella Di Vincenzo,
• Antonio Palumbo Piccionello,
• Alberto Spinella,
• Delia Chillura Martino,
• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2019, 15, 633–641, doi:10.3762/bjoc.15.59

• characteristic -N3 stretching band at 2103 cm−1. Interestingly, spectra show also a band at ca. 1688 cm−1, in a position consistent with the presence of a urethane carbonyl group. The latter finding provides a confirmation of the formation of oxazinanone derivatives shown in Scheme 4. On passing to NMR

• characterization (the complete collection of spectra is reported in Supporting Information File 1), the apparently very complex 1H NMR spectrum of mixture I (Supporting Information File 1, Figure S1) is characterized by the presence of various sets of signals, which are indeed easily recognizable, namely: i) a

Generation of 1,2-oxathiolium ions from (arysulfonyl)- and (arylsulfinyl)allenes in Brønsted acids. NMR and DFT study of these cations and their reactions

• Stanislav V. Lozovskiy,
• Alexander Yu. Ivanov,
• Olesya V. Khoroshilova and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2018, 14, 2897–2906, doi:10.3762/bjoc.14.268

• the case of the cation Bf, the signals of two isomers were found in the spectra in a ratio of 5 to 1. These isomers appear due to cis-, trans-orientation of t-Bu and ArS groups in the five-membered ring. To the best of our knowledge, this is one of the first examples of full NMR characterization of

Enhanced single-isomer separation and pseudoenantiomer resolution of new primary rim heterobifunctionalized α-cyclodextrin derivatives

• Iveta Tichá,
• Gábor Benkovics,
• Milo Malanga and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2018, 14, 2829–2837, doi:10.3762/bjoc.14.261

• same yield 4% and 4%, whereas the AD regioisomer 8d was obtained in 3% yield (calculated from the starting 6A-azido-α-CD) thus corresponding with the HPLC regioisomeric ratios. Subsequently, each regioisomer was characterized by NMR, HRMS, IR and optical rotation measurements. NMR characterization of

Calixazulenes: azulene-based calixarene analogues – an overview and recent supramolecular complexation studies

• Paris E. Georghiou,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Hidetaka Nishimura,
• Jaehyun Lee,
• Atsushi Wakamiya and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2018, 14, 2488–2494, doi:10.3762/bjoc.14.225

• by Lash and Colby in their syntheses of 3 and 4. Although 5 was not sufficiently soluble in CS2, benzene, toluene or 1,2-dichlorobenzene to enable 1H NMR solution titration studies to be conducted with fullerene C60, a dilute solution of 5 in dichloromethane-d2 could be obtained that enabled its NMR

• characterization. This finding suggested to us that solution complexation studies with other electron-deficient suitable guests could be conducted in dichloromethane (DCM). The concentrations that could be obtained with DCM were too dilute for typical NMR titration studies, but we judged that they could instead be

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• between the reactive groups during the construction of the polymer network, as compared with the flexible linkers A1–A3 (see below). Solid-state NMR characterization The CP-MAS solid-state NMR technique has been proven a versatile and powerful tool for the structural characterization of materials and

Cyclodextrins tethered with oligolactides – green synthesis and structural assessment

• Cristian Peptu,
• Mihaela Balan-Porcarasu,
• Alena Šišková,
• Ľudovít Škultéty and
• Jaroslav Mosnáček

Beilstein J. Org. Chem. 2017, 13, 779–792, doi:10.3762/bjoc.13.77

• L-LA monomer, noted with F2. The F2 fraction was further purified by partial removal of unreacted monomer through sublimation under vacuum at 40 °C temperature, in order to facilitate the NMR characterization. The unfractionated samples were first assessed by liquid chromatography with evaporative

Novel β-cyclodextrin–eosin conjugates

• Gábor Benkovics,
• Damien Afonso,
• András Darcsi,
• Szabolcs Béni,
• Sabrina Conoci,
• Éva Fenyvesi,
• Lajos Szente,
• Milo Malanga and
• Salvatore Sortino

Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

• can be eventually recovered. NMR characterization of eosin-appended β-CDs, 2–β-CD and 4–β-CD Solutions in deuterated DMSO (DMSO-d6) were used for NMR measurements, in order to preserve a molecularly dispersed form of the CD derivatives during characterization. The 1H NMR spectra of both conjugates

Correction: Synthesis, dynamic NMR characterization and XRD studies of novel N,N’-substituted piperazines for bioorthogonal labeling

• Constantin Mamat,
• Marc Pretze,
• Matthew Gott and
• Martin Köckerling

Beilstein J. Org. Chem. 2017, 13, 301–302, doi:10.3762/bjoc.13.32

Synthesis, dynamic NMR characterization and XRD studies of novel N,N’-substituted piperazines for bioorthogonal labeling

• Constantin Mamat,
• Marc Pretze,
• Matthew Gott and
• Martin Köckerling

Beilstein J. Org. Chem. 2016, 12, 2478–2489, doi:10.3762/bjoc.12.242

Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

• M. Fernanda N. N. Carvalho,
• M. João Ferreira,
• Ana S. O. Knittel,
• Maria da Conceição Oliveira,
• João Costa Pessoa,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2016, 12, 732–744, doi:10.3762/bjoc.12.73

• developed by means of DFT calculations on potential transition states. Keywords: amino acids; camphorsulfonylimine; DFT calculations; NMR characterization; Strecker degradation; Introduction Among the many derivatives of natural camphor, oxoimine 1 (Figure 1) shows an especially versatile chemistry. The C

New synthetic strategies for xanthene-dye-appended cyclodextrins

• Milo Malanga,
• Andras Darcsi,
• Mihaly Balint,
• Gabor Benkovics,
• Tamas Sohajda and
• Szabolcs Beni

Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

• supramolecular assembly of the xanthene-dye-appended cyclodextrins were developed based on the set of data collected by the extensive NMR characterization. Keywords: DMT-MM; fluorescein; rhodamine; supramolecular assembly; Introduction Cyclodextrins (CDs) are cyclic oligosaccharides consisting of 6, 7 or 8

• , fluorescent single-isomer CD; more commonly, the system is a mixture of unsubstituted and substituted CD derivatives. Although some data are reported in the literature for the characterization of fluorescently labeled CDs, a full NMR characterization, to the best of our knowledge, has never been presented and

• extensively characterized by NMR spectroscopy. NMR characterization of Rho-β-CD The proton NMR spectrum shown in Figure 4 is a typical spectrum of an asymmetric cyclodextrin. The sharpness of the peaks suggests the high purity of the compound. The two constituent parts of the molecule can be easily recognized

Polydisperse methyl β-cyclodextrin–epichlorohydrin polymers: variable contact time ¹³C CP-MAS solid-state NMR characterization

• Isabelle Mallard,
• Davy Baudelet,
• Franca Castiglione,
• Monica Ferro,
• Walter Panzeri,
• Enzio Ragg and
• Andrea Mele

Beilstein J. Org. Chem. 2015, 11, 2785–2794, doi:10.3762/bjoc.11.299

Two strategies for the synthesis of the biologically important ATP analogue ApppI, at a multi-milligram scale

• Janne Weisell,
• Jouko Vepsäläinen and
• Petri A. Turhanen

Beilstein J. Org. Chem. 2015, 11, 2189–2193, doi:10.3762/bjoc.11.237

• any NMR characterization data, only HPLC and MS data were presented, and these are rather unsatisfactory methods with which to prove the purity of a product. They also stated that there was 5–10% ADP (adenosine diphosphate) as an impurity in some preparations and that it is possible that there may