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

• Department, Universidad del Valle, Cali 76001, Colombia Australian National Phenome Center, and Center for Computational and Systems Medicine, Health Futures Institute, Murdoch University, Harry Perkins Building, Perth WA6150, Australia Department of Chemistry, Case Western Reserve University (CWRU

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• vigorously used to search for novel compounds in recent years due to the rapid improvement of DNA sequence technologies and computational approaches to analyze BGCs [1][3]. Our research group previously identified the secondary metabolite-specific nitrous acid biosynthetic pathway, named ANS (aspartate

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

• addition, with computational studies we demonstrated the greater stability of BF3 in BMIm-BF4 compared to BF3·Et2O [103]. Based on the ever increasing need to identify new eco-friendly catalysts and/or reaction media for the hydration of alkynes, and considering our previous works on ILs and

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

• , computational approaches could be efficiently used to gain insight into protein–GAG interactions that take place at single-molecule levels [32]. More than a complementary tool, computational approaches provide a better understanding of the role of individual interaction partners (including GAGs, solvent, and

• ions) by bringing often new and experimentally inaccessible details [33][34]. However, for computational researchers, there are still many challenges to overcome that originate from the physicochemical properties of GAGs, viz. their highly polarized (anionic) nature, their periodicity, and the

• explanation and prediction of GAG specificity [35]. Computational methodologies like molecular docking and molecular dynamics (MD) have proven to be successful in modelling protein–GAG interactions, particularly examining the fundamental questions related to these interactions such as their specificity, the

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

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

• compounds [12]. Research using computational methods to investigate how benzo and benzocyclobutadiene annulations impact the ring current density of biphenylene derivatives reveals that the antiaromatic (paratropic) current density in the 4-ring structure can range widely, shifting from highly antiaromatic

• phenomenon is a result of non-radiative deactivation was corroborated by detailed computational chemistry studies. In continuation of the aforementioned work by Wagner and co-workers [49], they have synthesized also "v" and "z"-shaped POAs, wherein biphenylene groups are angularly incorporated into the 1,4

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

• /23 = 4.6 of the respective monomer 22, which was already best among fullerene monomers. In computational simulations, the positive maximum of the MEP surface next to the amine base was the same for dimer 37 (+13.9 kJ mol−1) and monomer 22 (+13.8 kJ mol−1), supporting that the dramatic increase in

• below that of unsubstituted NDIs despite stronger π acidity. Supported by experimental and computational data, this poor performance of dyad 46 was explained by lone-pair π interactions of the fullerene with the donating oxygens. These lone-pair π interactions were even more impactful on the sulfone

• level. Compared to the sulfoxides in 46, the catalytic activity of dyad 47 decreased rather than increased despite stronger π acidity. Supported by computational predictions [80][81], record activities in anion–π catalysis with fullerene dimers called for higher oligomers. However, synthetic efforts

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• absorption and emission maxima of 411 and 520 nm, respectively, with a mega Stokes shift of 109 nm and fluorescence quantum yields both in the solid state (41%) and in solution (86%). The optical properties were supported by computational chemistry using density functional theory for optimized geometry and

• . The high thermal stability is profitable for the preparation of stable and durable OLED devices. Computational chemistry Ground-state geometry optimization of DMB-TT-TPA (8) was performed using density functional theory (DFT) calculations with the Gaussian 16 software at the B3LYP/6-31G (d,p) level

• model and synthesized in 85% yield. Its photophysical properties were investigated by UV–vis and fluorescence spectroscopy. The obtained experimental results were found to be in good agreement with computational investigations. An OLED fabrication, where DMB-TT-TPA (8) was employed as an emitter, showed

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• novel metallaphotoredox catalysis by combining the NaI/PPh3 photoredox catalyst with a Cu(I) catalyst to accomplish diverse C–O/N cross-couplings of alkyl N-hydroxyphthalimide esters 3 with various phenols/secondary amines 30 (Scheme 13) [24]. It was anticipated the utilization of computational methods

• NHC catalyst acted as a stabilizer for the EDA complex and generates a radical species, which was confirmed by further computational studies. Monofluoromethylation The monofluoromethyl (CH2F) group, which is commonly found in a lot of agrochemicals, pharmaceuticals, and materials, serves as a powerful

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

• transport [37][38]. Therefore, to better understand the charge mobility of compounds 1 and 2, we obtained their ground state geometry using DFT within the B3LYP/def2-TZVP(-f) level of theory (Figure 8a). To reduce computational efforts, isopropyl moieties were used instead of the large aliphatic

Trifluoromethylated hydrazones and acylhydrazones as potent nitrogen-containing fluorinated building blocks

• Zhang Dongxu

Beilstein J. Org. Chem. 2023, 19, 1741–1754, doi:10.3762/bjoc.19.127

• trifluoroacetaldehyde hydrazones. Jasiński et al. demonstrated that the CF3 group offered an appropriate electronic balance through experimental spectral analysis and computational DFT methods, and the hydrazones could be readily used to provide convenient access to azo tautomers under the acidic conditions [43]. The C

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

• File 12: Copies of IR, 1H and 13C NMR spectra of synthesized compounds and computational details. Funding This research was financially supported by the Russian Science Foundation (Grant No. 23-23-00324).

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

• liquors and, in both cases, XRD confirmed the obtention of the (E)-isomer, in an anti-conformation. Computational calculations (gas and water phases) were performed in order to confirm some of the structural and vibrational aspects of the compounds. An important intramolecular H bond involving the

• calculate the electrostatic potential over an electronic density map as well. For hdz-NO2, results show the alternated slipped stack motif involves the assembly of portions with opposite electrostatic potentials. Computational calculations were performed in order to confirm some of the structural and

• 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

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

• compound with the donor polymer PM6 to create BHJ nanoparticles and employed it in the hydrogen evolution reaction. This approach substantially reduced trap density, increasing the hydrogen evolution rate by 2–3 times compared to conventional inorganic/organic hybrid photocatalysts [30]. Computational

• ]. Several computational studies have also been performed to design dyes for optimized performance in DSSCs [46][47]. Shi and colleagues’ quantum modeling study sheds light on the optoelectronic properties of Qx-based dyes containing DPQ (Qx44a) or methoxy-substituted DPQ (Qx44b) as π units, highlighting the

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

• reduce computational costs (Figure 3a). The calculated ECD curve for 1′ agreed well with the experimental ECD spectra of 1 and 6, indicating that the aglycones of these compounds had an absolute configuration of 1R,3R,4R,6S,7R,9S,11S,12R,16S,17S (Figure 3b). Similarly, the absolute configurations of

• -arabinose), 16.20 (ᴅ-arabinose), and 22.14 (ʟ-rhamnose) min. Computational method Conformers of 1′, 2′, and 3 were generated using CONFLEX 8 with the MMFF94s force field [19] and a search limit of 5 kcal/mol, respectively. Similar conformers were excluded, yielding 9 conformers for 1′, 10 conformers for 2

Unraveling the role of prenyl side-chain interactions in stabilizing the secondary carbocation in the biosynthesis of variexenol B

• Moe Nakano,
• Rintaro Gemma and
• Hajime Sato

Beilstein J. Org. Chem. 2023, 19, 1503–1510, doi:10.3762/bjoc.19.107

• , computational chemistry including DFT [5][6][7][8][9], QM/MM [10][11][12][13][14][15][16] and QM/MM MD [14][15][16][17] calculations have been used for the biosynthetic studies of terpene/terpenoids [18]. Terpene-forming reactions, which involve various types of carbocation species stabilized by

• biosynthesis of trichobrasilenol [22], by combined methods of computational and experimental chemistry. Recently, Dickschat et al. reported the synthesis of a novel diterpene compound, variexenol B, using a substrate analogue called iso-GGPP (Scheme 1) [23]. This biosynthetic pathway has two interesting

• investigated the biosynthetic pathways using DFT calculations to validate the above-mentioned aspects. Results and Discussion The detailed structures of the intermediates and transition states were elucidated by computational analysis. Interestingly, we have found an interaction between the secondary

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

• ). Computational results Computations were performed using density functional theory (DFT) for the ground state and time-dependent DFT (TD-DFT) with Tamm–Dancoff approximation [24][25] for the excited states calculations, using the global hybrid MN15 functional by Truhlar [26] in combination with the def2-TZVP

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

• have been evaluated extensively through both qualitative and quantitative means. Methods of evaluation have included X-ray crystallography and spectroscopy (e.g., microwave, IR, Raman, NMR, NQR), as well as through computational determination of their electrostatic VS,max potentials (Figure 2), their

• positively charged. Halogen-bonded adducts of these have also been observed, which further illustrated the existence and properties of σ-holes in such HVI compounds. For example, I-7-pyr was characterized by X-ray crystallography and by computational methods, where molecular orbital (MO) analysis showed that

• halogen bonding had been invoked for years when describing reactions of such ylides. In 2022, Murphy et al. used computational analysis to assess iodonium ylides for their σ-holes, and found that two of these existed, with one situated opposite the arene and the other opposite the β-dicarbonyl motif

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

• coupling, i.e., the 3LE mediate 3CS → 1CS rISC in TADF [27]. The photochemical properties of each compound in different solvents are summarized in Table 5. Computational investigations The optimized ground state geometry of the dyads at the DFT-B3LYP/6-31G (d) level of theory determined with Gaussian 09

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

• absolute configurations, were identified by comprehensive spectroscopic analyses and computational methods. Inspired by our previous study on the same kinds of skeletons, we speculated that the new compounds have anticancer and anti-inflammatory activities. The results did not show any activity, but they

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

• scope. Results of selected optimization experiments. Supporting Information Supporting Information File 174: Characterization data for all compounds, computational details, and picture of NMR spectra. Funding This work was supported by the Slovak Research and Development Agency under the Contract no

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

• functionalization of chelating molecules under action of a Rh(NHC) system. Based on the computational studies and experimental data, the proposed mechanism (Scheme 40b) describes that the Rh(I) complex ligated to tert-butoxide and NHC (IMes·HCl) 215 is a catalytically active species. The Rh–hydride species 217 is

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

• , accompanied by two known flavan derivatives 5 and 6 and a known olefine acid (9) were isolated from whole bodies of Kronopolites svenhedini (Verhoeff). The structures of the new compounds were determined by 1D and 2D nuclear magnetic resonance (NMR) and other spectroscopic methods, as well as computational

• Table 4. Kronoponoid B (8): light yellow gum; [α]D25 +2.50 (c 0.40, MeOH); UV (MeOH) λmax, nm (log ε): 202 (3.81); HRESIMS (m/z): [M + H]+ calcd for C17H31O3, 283.2268; found, 283.2268 ; 1H and 13C NMR data, see Table 4. Computational methods The CONFLEX 7 searches, considering the Molecular Merck force

Bromination of endo-7-norbornene derivatives revisited: failure of a computational NMR method in elucidating the configuration of an organic structure

• Demet Demirci Gültekin,
• Arif Daştan,
• Yavuz Taşkesenligil,
• Cavit Kazaz,
• Yunus Zorlu and
• Metin Balci

Beilstein J. Org. Chem. 2023, 19, 764–770, doi:10.3762/bjoc.19.56

• Kutateladze claimed that based on an applied machine learning-augmented DFT method for computational NMR that the structure of the product, (1R,2R,3S,4S,7s)-2,3,7-tribromobicyclo[2.2.1]heptane was wrong. With the aid of their computational method, they revised a number of published structures, including ours

• erroneous mechanistic pathway. Keywords: bromination; computational NMR; γ-gauche effect; NMR; NOE-Diff experiments; Introduction Nuclear magnetic resonance (NMR) spectroscopy is one of the most important analytical tools used to determine the structure of organic compounds. NMR not only confirms the

• have developed a machine learning-augmented DFT method for computational NMR, DU8ML, for fast and ‘accurate’ computational approaches [2]. They applied this computational method to a number of previously published organic compounds and claimed to have revised some structures and proposed new mechanisms

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

• with an α,β-butenolide-type, whereas compound 3 is a dimeric caged cassane diterpenoid with unique 6/6/6/6/6/5/6/6/6 nonacyclic ring system. The structures of 1 and 3 were characterized by extensive spectroscopic analysis combined with computational ECD analyses. The α-glucosidase inhibitory activity