Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones

• Carola Tortora,
• Christian A. Fischer,
• Sascha Kohlbauer,
• Alexandru Zamfir,
• Gerd M. Ballmann,
• Jürgen Pahl,
• Sjoerd Harder and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59

• isomer, with a more acute Ca–N–C angle of 92°, has greater resemblance to a (here absent) side-on form (found to dominate computationally for Ca(CN)2 in the gas phase) [54]. Fortunately, that isomer in which the isonitrile carbon is closer to the imine carbon (i.e., the hydrocyanation reaction center

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• dimeric molecules, instead of expected 9,10-(perfluoroalkyl)2ANTH [26]. To the best of our knowledge, perfluorobenzylation of anthracene has not been reported prior to this study. The only PAH perfluorobenzylations were reported by our group: with CORA using gas-phase solvent-free reactions in sealed

• ampules and with PERY using solution-phase reactions at elevated temperatures in the presence of Cu metal or another reducing agent [22]. In this study we first explored the approaches from our previous work: a high-temperature gas-phase reaction between ANTH and BnFI [18][19], and a solution-phase

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• (Scheme 2). The structures of tautomeric forms of 7a, 7b, 8a, 8b and their energy characteristics were calculated by PBE0/6-311+G(d,p) method in the gas phase and polar solvent (DMSO) (Table 1, Figure 1 and Supporting Information File 3). According to the obtained data, the (NH) isomers of 7 and 8 are

• studied compounds. The difference in the energy characteristics of the (NH) and (OH) tautomeric forms of compounds 7a, 7b, 8a, and 8b in the polar solvent and the gas phase is small (2.0–3.8 kcal/mol), and probably the nature of the solvent can influence the shift of the equilibrium towards one of the

• Tukey’s post hoc test of significance. IC50 values were determined in the RStudio development environment using the DRC software package [40]. Structural characteristics of (NH) and (OH) tautomeric forms of compounds 7 and 8 in the gas phase according to PBE0/6-311+G(d,p) calculations. Bond lengths are

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• dihydroxyviolanthrone. Chemical structures of 2b and 3b. Optimised ground state geometries of compounds 2 and 3 calculated using B3LYP/6-311G(d,p) in the gas phase. Views of the crystal structure of 3b (left, shows displacement ellipsoids drawn at 50% probability level, right showing the twisted conformation

Mechanochemical difluoromethylations of ketones

• Jinbo Ke,
• Pit van Bonn and
• Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

• the gas phase than in solution [32][33], it has remained a challenge to control such reactions. Our group has recently reported a mechanochemical difluoromethylation of primary, secondary, and tertiary alcohols [34], yielding products with difluoromethoxy groups, which are promising organofluorine

Computational design for enantioselective CO₂ capture: asymmetric frustrated Lewis pairs in epoxide transformations

• Maxime Ferrer,
• Iñigo Iribarren,
• Tim Renningholtz,
• Ibon Alkorta and
• Cristina Trujillo

Beilstein J. Org. Chem. 2024, 20, 2668–2681, doi:10.3762/bjoc.20.224

• presence of the CO2 adduct. In the gas phase and isolated, the isomerisation of the epoxide exhibits a barrier of 52.6 kcal·mol−1. In the case of F2_NB_H_H, the barrier is reduced to 37.0 kcal·mol−1. CO2 later reacts with the aldehyde, forming the insertion product already observed in mechanism 1 (Min2

Deciphering the mechanism of γ-cyclodextrin’s hydrophobic cavity hydration: an integrated experimental and theoretical study

• Stiliyana Pereva,
• Stefan Dobrev,
• Tsveta Sarafska,
• Valya Nikolova,
• Silvia Angelova,
• Tony Spassov and
• Todor Dudev

Beilstein J. Org. Chem. 2024, 20, 2635–2643, doi:10.3762/bjoc.20.221

•  3. The enthalpies estimated for the subsequent binding process of water molecules to γ-CD in both the gas phase (ΔH1) and aqueous medium (ΔH78) at both levels of theory are presented in Table 1. The two sets of calculations using different basis sets (M062X/6-31G(d,p) and M062X/6-311++G(d,p)//M062X

• /6-31G(d,p)) follow the same trend of changes. All interactions in the gas phase are favorable and characterized by a negative ΔH1. In principle, the formation of new hydrogen bonds is beneficial, while the breaking of existing ones is unfavorable to the hydration process. For this reason, the change

• the γ-CD cavity, i.e., what is the saturation point of the γ-CD internal hydration as determined by DFT modeling of possible γ-CD–nH2O complexes? In general, the gas-phase calculations at the two levels of theory (and in aqueous media at the M062X/6-31G(d,p) level) show that the sequential insertion

Machine learning-guided strategies for reaction conditions design and optimization

• Lung-Yi Chen and
• Yi-Pei Li

Beilstein J. Org. Chem. 2024, 20, 2476–2492, doi:10.3762/bjoc.20.212

• theoretical calculations are typically restricted to gas-phase reactions [31]. Despite these challenges, recent advances in quantum chemical methods have shown that theoretical calculations can provide practical guidance for validating experimental results [32]. Thus, we posit that the role of theoretical

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• includes effective core potentials for iodine. Empirical dispersion was accounted with Grimme’s D3 [72][73] correction including Becke–Johnson damping [74]. Computations were performed both in the gas phase (i.e., individual molecules with thermal corrections at 298.15 K based on ideal gas assumptions) and

• structures are shown in Table 8. In the gas phase, there is little difference in enthalpy between the two structures. For Cl, Br, and I, the 1C4 structures are predicted to have slightly lower enthalpies. However, as these differences are much smaller than 1 kcal/mol, one should conclude that the structures

• structures in the gas phase and in chloroform (PCM). Thermal corrections are reported at 298.15 K. Second order perturbation theory energies of the Fock matrix in the NBO basis for 4C1 and 1C4 structures, from CAM-B3LYP-D3BJ/Def2TZVP results. Only results from CHCl3 solvation (PCM) are reported as gas phase

Divergent role of PIDA and PIFA in the AlX₃ (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study

• Kevin A. Juárez-Ornelas,
• Manuel Solís-Hernández,
• Pedro Navarro-Santos,
• J. Oscar C. Jiménez-Halla and
• César R. Solorio-Alvarado

Beilstein J. Org. Chem. 2024, 20, 1580–1589, doi:10.3762/bjoc.20.141

• values as Gibbs free energy at 298 K and 1 atm. All our calculations were performed in the gas phase. Then, the solvent effects were included according to the polarizable continuum model via the solvent model density (SMD) option considering Truhlar’s model [36][37][38][39][40] and MeCN as the solvent

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• interactions [4]. Protonation of 3-fluoropyrrolidine generates the 3-fluoropyrrolidinium cation, and this typically results in a highly favored conformation in both the gas phase and solution where the fluorine and nitrogen atoms are cis, mirroring the behavior observed in analagous 4- and 6-membered ring

• -fluoroalkylamines and the respective cations [6]. Intramolecular hydrogen bonds involving either the carboxy or hydroxy group of 4R- and 4S-hydroxyproline have been identified as key factors in stabilizing the favored conformations in the gas phase. Therein, the contribution of a gauche effect due to electron

• only slightly more stable than the other three conformers in both the gas phase and implicit water [4]. Hence, it appears that strong intramolecular interactions, and not only hydrogen bonding, govern the orientation of the fluorine atom in the F‒C‒C‒N fragment, favoring the cis-isomer of 3

Predicting bond dissociation energies of cyclic hypervalent halogen reagents using DFT calculations and graph attention network model

• Yingbo Shao,
• Zhiyuan Ren,
• Zhihui Han,
• Li Chen,
• Yao Li and
• Xiao-Song Xue

Beilstein J. Org. Chem. 2024, 20, 1444–1452, doi:10.3762/bjoc.20.127

• iodine [61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76] and the computational database of organic species by Paton and co-workers [77], geometry optimizations and single point energy calculations for homolytic BDEs are both performed using M06-2X/def2-TZVPP [78][79][80] in the gas phase

A comparison of structure, bonding and non-covalent interactions of aryl halide and diarylhalonium halogen-bond donors

• Nicole Javaly,
• Theresa M. McCormick and
• David R. Stuart

Beilstein J. Org. Chem. 2024, 20, 1428–1435, doi:10.3762/bjoc.20.125

• -qzvpp for iodine and tellurium and in the gas phase. In our present work using M06-2x/6-311+G(d) with def2-txvpp for iodine and astatine, we observed excellent agreement in the correlation between orbitals used on the halonium center and the C–X–C bond angle, i.e., molecular geometry, from our prior

Stability trends in carbocation intermediates stemming from germacrene A and hedycaryol

• Naziha Tarannam,
• Prashant Kumar Gupta,
• Shani Zev and
• Dan Thomas Major

Beilstein J. Org. Chem. 2024, 20, 1189–1197, doi:10.3762/bjoc.20.101

• stereochemistry. Theory is an important tool in understanding the complex chemistry in terpene synthesis. Gas-phase and in-enzyme tools have been employed extensively to understand terpene chemistry in general and terpene synthases in particular [21][22][23][24][25][26][27][28][29]. In the current work, we

• calculations with zero damping [35]. Extensive benchmarking on different sets of classical and non-classical carbocations have shown that M06-2X in conjunction with the 6-31+G(d,p) basis set performs well for carbocations [29][36], and here we confirm this finding for hydroxylated carbocations. All gas-phase

Novel route to enhance the thermo-optical performance of bicyclic diene photoswitches for solar thermal batteries

• Akanksha Ashok Sangolkar,
• Rama Krishna Kadiyam and
• Ravinder Pawar

Beilstein J. Org. Chem. 2024, 20, 1053–1068, doi:10.3762/bjoc.20.93

• /kg), and TBR barrier (121.76 kJ/mol) of prototype NBD/QC in the gas phase. The outcomes render useful insights into the stability and properties of bicyclic diene-based photoswitches having elongated unsaturated bridges and indeed paves the way for the rational design of practical MOST systems

• exhibit the best storage energy capacities and high TBR barriers. The calculated energy storage capacities (138.28–165.74 kJ/mol) of the studied bridged bicyclic dienes are ≈1.5 times higher than the prototype NBD/QC (≈96 kJ/mol) pair in the gas phase. The estimated energy barriers for the thermal back

• isomerization in the studied photoswitching systems are large enough to store the harvested energy for several months or longer in the gas phase. The time-dependent calculations using the TD-M062X functional reveal that an elongation of the unsaturated bridge using –(CO)– and –NH– red-shifts the absorption

Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• exhibits a noteworthy impact on the thermal stabilities (analyzed by TGA) of the compounds. The single-crystal X-ray diffraction of DPQD 2b exhibits a desirable herringbone solid-state arrangement for a potential OFET application. Complementary gas-phase computational analysis has provided insight into the

• illustrated in Figures S37–S41 (Supporting Information File 1). This serves as good evidence that the synthesized compounds exhibit no signs of aggregation in DMSO within the assessed concentration range (i.e., 2.5–45 μM). Electronic structure calculations Gas-phase computational investigations were conducted

• and DPQDs were established using gas-phase computational DFT analysis (B3LYP/6-31+G* level of theory), UV–visible spectroscopy, thermal analysis, and X-ray analysis in the solid state for 2b, 5b, and 6b. The primary takeaways from the work concern the attractive functional consequences of efficiently

Advancements in hydrochlorination of alkenes

• Daniel S. Müller

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

• . Thermodynamic and theoretical data provide hydride affinities, which correspond to the negative heat of formation for the combination of a hydride anion with a given cation in the gas phase (Figure 2) [26][29]. It is noteworthy that, in contrast to the hydride affinity scale, the Mayr scale considers energetic

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• nitrogen. Thus, the rate of intramolecular hydroamination is enhanced by a more nucleophilic nitrogen. Another qualitative interpretation is that rates are enhanced by carbonyl basicity. Gas-phase basicity measurements indicate that ureas are more basic than amides [47][50], and here the most Lewis base

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

• Eiichi Kayahara,
• Yoshiyuki Mizuhata and
• Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

• present in solution when the solvent effect is negligible. Formation of complex 1 in the gas phase was highly exothermic with ΔG = −222 kJ mol−1 at 298.15 K and 1.00 atm, and this value is about two times higher than that of the complex formation of neutral [10]CPP⊃[5]CPP (ΔG = −114 kJ mol−1). Therefore

• , the same trend of the relative stability between [10]CPP⊃[5]CPP2+ and [10]CPP⊃[5]CPP was also observed in the gas phase. The significant increase in relative stability in the gas phase compared to the solution state is likely due to the overestimation of electronic interactions due to CT in the

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• isoindigo derivatives are photostable, and no photochromism was reported for these compounds till 2019, when Oomens and co-workers provided an evidence for the E–Z photoisomerization of the protonated isoindigo in the gas phase (Figure 16) [77]. The backward Z–E photoisomerization of the protonated

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

• singlet state [10]. Although only a few analyses of the reaction mechanisms have been studied due to the complexity of the system, several intermediates inside the CNT have been proposed [3][11][12], which may be different from those proposed to take place in the gas phase or in the solid state at high

• -dimensional space within the CNT and compared the results with those for the same reaction in the gas phase. We assumed that the cation radical mechanism takes place, that is, the ionized CNT generates a radical cation C60•+ that reacts with a C60 molecule to yield different C120•+ dimers. The energies for

• in the latter (Figure 1). Dimer 1-Cs is at our computational settings (PBE/PW), more than 15 kcal mol−1 higher in energy than dimer 1-D2h, the one characterized by X-ray crystallography in the solid state, both in the gas phase and inside the CNT. Similar lower stabilities for dimer 1-Cs are also

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

• liquid bulk to liquid–gas interface, and transfer from liquid–gas interface to gas phase [43]. Since the inert gas was purged into the reactor continuously, the generated hydrogen could also directly be transferred from the photocatalyst surface to the gas phase if a gas bubble got in contact with the

• maximum hydrogen generation rate was 1.5 times higher at 740 rpm than at 430 rpm. This gives evidence that increased convection improves the mass transfer of generated hydrogen from the liquid phase to the gas phase or even directly from the catalyst to the gas phase. This is in line with the measured

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

• .19.134 Abstract Carbohydrate sequencing is a formidable task identified as a strategic goal in modern biochemistry. It relies on identifying a large number of isomers and their connectivity with high accuracy. Recently, gas phase vibrational laser spectroscopy combined with mass spectrometry tools have

• proposed to identify the presence of structural features in oligosaccharides based on their gas-phase IR spectra [11]. To the best of our knowledge, machine learning classification studies have not been reported to identify saccharides using MS–IR carbohydrate analysis. Here, we report a study of a

• approach is based on the IRMPD spectroscopic scheme (infrared multiple photon dissociation), which is the combination of mass spectrometry and IR spectroscopy. IRMPD is an action spectroscopy method that allows recording IR absorption spectra of isolated gas-phase ions, based on the measurement of the

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

• for hdz-CH3 (0.648 Å in the gas phase and 0.623 Å in water). However, the small RMSD values in all cases showed that the calculated structures correlated pretty well with the respective experimental ones [45][46]. The biggest differences between the theoretical structures and the experimental data

• errors of 2% (hdz-CH3) and 0% (hdz-NO2). In general, the structures calculated involving the IEFPCM formalism (water phase) displayed the best agreement with the experimental data. Regarding the vibrational characterization, infrared spectra were also calculated with both B3LYP/6-311G(d,p) – gas phase

• intensity bands, respectively, at 1519 and 1336 cm−1. These modes were calculated at 1608 and 1379 cm−1 in the gas phase. Although N-acylhydrazones are usually prone to undergo speciation in DMSO-d6 solution [47], 1H NMR measurements showed the existence of only one set of signals in the spectra of hdz-CH3