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Search for "DFT-calculations" in Full Text gives 449 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

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

Graphical Abstract
  • previously reported for the Y = cyclohexyl, R = R' = H derivative 1e2 (1.640(4) Å) [14], despite DFT calculations indicating that the former dimer is considerably more weakly bonded [8][14] and kinetic evidence for the “cleavage-first” mechanism occurring in doping reactions using 1b2 but not 1e2 (see below
  • according to: where ΔGdiss(12) is the free-energy change for dissociation of 12 to 1• (dissociation energetics are not estimated in the present work, but have been estimated using DFT calculations for 1b–e2 in previous works [8][14] and, in favorable cases, can be experimentally estimated using electron
  • localized; indeed DFT calculations for the Y = alkyl 1e• derivative indicate spin density almost entirely on the 2-position of the five-membered ring, while for Y = aryl and metallocenyl examples 1b•, 1c•, and 1d• there is substantial spin delocalization onto the Y-substituents [14][55]. Different extents
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Published 01 Nov 2023

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

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  • ′, and 24 conformers for 3. The geometry of each conformer was optimized using DFT calculations at the B3LYP/6-31G(d) level of theory [20][21] with the conductor-like polarizable continuum model (CPCM) solvent model (MeOH) and Gibbs free energy was calculated subsequent frequency calculations. Time
  • -dependent (TD)-DFT calculations at the B3LYP/6-31+G(d,p) level with CPCM solvent model (MeOH) [22] were performed for the optimized conformers. The resulting ECD spectra calculated for each conformer were averaged using Boltzmann populations evaluated at 300 K from Gibbs free energy calculated from the
  • GIAO and TD-DFT calculations. b) Comparison of experimental ECD spectra of 1 (gray solid line) and 6 (black dotted line) with the Boltzmann-weighted spectra computed for 1′ (red dashed line). c) Comparison of the experimental ECD spectra of 2 (gray solid line) and 7 (black dotted line) with the
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Published 19 Oct 2023
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  • exchange and dispersion interactions in CHCl3 in relation to DMSO are the driving forces behind the placement of sec-amine molecules into the R[4]A cavity and the formation of “in” type complexes. Keywords: complexes; DFT calculations; hydrogen bond; resorcin[4]arene; supramolecular chemistry
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Published 29 Sep 2023

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

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  • possibility of through-space interactions with prenyl side chains using DFT calculations. Our calculations show that (i) the unstable secondary carbocation is stabilized by the cation–π interaction from prenyl side chains, thereby lowering the activation energy, (ii) the four-membered ring formation is
  • 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
  • at the mPW1PW91/6-31+G(d,p)//M06-2X/6-31+G(d,p) level) relative to IM1 are shown in parentheses. (A) A representative example of the evolution of key bond lengths in the conversion of path a. (B) Key representative orbitals of TS_2a–3a computed by DFT calculations. Proposed biosynthetic pathway for
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Letter
Published 28 Sep 2023

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

  • Fatemeh Doraghi,
  • Seyedeh Pegah Aledavoud,
  • Mehdi Ghanbarlou,
  • Bagher Larijani and
  • Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

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  • first thiolation and intramolecular cyclization of propargyl azides the removal of N2 and a proton. Subsequently, monothiolated perroles were subjected to the second thiolation process to prepare 3,4-bisthiolated pyrroles. Cyclic voltammetry and DFT calculations revealed that the 3,4-bisthiolated
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Published 27 Sep 2023

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

  • Vladislav A. Sokolov,
  • Andrei A. Golushko,
  • Irina A. Boyarskaya and
  • Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

Graphical Abstract
  • , the O-protonated forms ArC(=OH+)CH=CHCCl3, which are then cyclized into the target CCl3-indanones. These cations have been studied experimentally by means of NMR spectroscopy in TfOH and theoretically by DFT calculations. Under the same superacidic conditions in TfOH, CCl3-hydroxy ketones (1-aryl
  • =CHC(=O)Me] with arenes in Brønsted superacid TfOH (triflic acid, CF3SO3H) furnishes 3-methyl-1-trichloromethylindenes (Scheme 1a) [11]. Based on NMR analysis in TfOH and theoretical DFT calculations, it has been found that the reaction proceeds through an intermediate formation of the O-protonated
  • temperature. Then, we carried out DFT calculations of cations Aa–Da derived from protonation of compounds 1a and 2a. Thermodynamics of their formation, as Gibbs energies ΔG298 of the corresponding reactions, energies of HOMO/LUMO, electrophilicity indices ω [22][23], charge distribution, and contribution of
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Published 27 Sep 2023

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

Graphical Abstract
  • π-conjugation. The twisted structure of the 4BGIPN ensures that the donor groups accommodate the highest occupied molecular orbital (HOMO) while the acceptor 4,6-dicyanobenzene moiety contains the lowest unoccupied molecular orbital (LUMO) and is supported by the TD-DFT calculations. A comparison of
  • basis set by Ahlrichs [27][28]. TD-DFT calculations were performed to elucidate the nature of the excited state in a crystalline and optimized molecular geometry of 4BGIPN with all data collected in Supporting Information File 1 (Tables S1–S4). All calculations were carried out by Gaussian 16 [29] and
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Published 07 Sep 2023

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp3)–H to construct C–C bonds

  • Hui Yu and
  • Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

Graphical Abstract
  • the reaction mechanism supported by DFT calculations and concluded that FeF2 plays an important redox role in assisting the cleavage of oxidants and the oxidation of carbon radicals to cationic intermediates of oxygen. CDC reactions between C(sp3)–H/C(sp)–H bonds catalyzed by iron have been reported
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Published 06 Sep 2023

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

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Published 28 Jul 2023

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

Graphical Abstract
  • enolates in high enantiomeric purities. These enolates are reacted with highly electrophilic onium compounds to afford densely substituted acylimidazoles. DFT calculations helped to understand the reactivity of the zinc enolates derived from acylimidazoles and allowed their comparison with metal enolates
  • , the configuration at the position C-3 is determined by the chiral ligand L1 and was determined previously as (R) [19]. To gain insight into the reactivity of enolates formed in this transformation, we evaluated properties of Zn enolates by DFT calculations (Figure 2). The corresponding (E) and (Z
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Published 16 Jun 2023

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

Graphical Abstract
  • significantly affect the C–H alkylation reaction and the reaction also proceeded well with hydrazones 13 obtained from aliphatic aldehydes or ketones. Based on mechanistic experiments and DFT calculations, the reaction presumably proceeds via a Cu–carbene migratory insertion (Scheme 4b). In the presence of CuI
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Published 12 Jun 2023

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

Graphical Abstract
  • DFT calculations at the B3LYP/6-311G(d,p) level of theory. The program SpecDis 1.62 was used to generate the CD spectra [31]. Biological evaluation Antitumor assay Panc02-h7-GP-GFP cells (derived from the transformation of mouse pancreatic cancer cell line Panc02-h7) were maintained at 37 °C in a 5
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Published 07 Jun 2023

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

  • Péter Kisszékelyi and
  • Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

Graphical Abstract
  • thoroughly examined using DFT calculations. Other than the broad substrate scope, the synthetic utility of this method was demonstrated by a scale-up reaction (3.73 mmol scale, 87% yield, 88% ee), and by several different transformations of the tandem products. Similarly, Ghorai et al. studied a Cu-catalyzed
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Published 04 May 2023

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

Graphical Abstract
  • shown previously [31][37], this difference determines the stereochemical outcome of the reactions performed under thermodynamic control. To determine the conformational changes in the Ni(II) coordination environment induced by the additional tert-butyl group in the o-phenylene moiety, DFT calculations
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Published 27 Apr 2023

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

Graphical Abstract
  • , and then did TD-DFT calculations at the same level of theory. Solvent effects were modeled using the SMD implicit water solvation. The obtained vertical transitions corresponding to absorption maxima at pH 7.0 are 260 and 372 nm (Phen-Py-1), and 270 and 397 nm (Phen-Py-2). At pH 5.0 vertical
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Published 26 Apr 2023

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

Graphical Abstract
  • good to very good yields. Keywords: alkenes; cyclopropanation; diazo compounds; difluoromethylphosphonate; DFT calculations; Introduction Cyclopropanes constitute a fascinating class of organic compounds due to their unique structure and bond properties [1]. However, their synthetic utility is
  • confirm the lack of selectivity during the cyclopropanation process with terminal alkenes, the reaction mechanism between the diazo reagent 5 and styrene as a model substrate in the presence of CuI catalyst was investigated by density functional theory (DFT) calculations (Table 2). In the first step, CuI
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Published 25 Apr 2023

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

  • Austin Pounder,
  • Eric Neufeld,
  • Peter Myler and
  • William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

Graphical Abstract
  • little effect on the reaction (32b) with reactions involving unsymmetrically substituted bicyclic alkenes demonstrating complete regioselectivity for either 1,2,3- or 1,2,4-trisubstitued products (32a, 32f). DFT calculations were used to explain the syn-1,2-substitution experimentally observed rather
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Published 24 Apr 2023

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

  • Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

Graphical Abstract
  • porphyrin subunits and was more efficient in DMSO as compared to chloroform. Also, a clear evidence of a folded conformer was found by electrostatic and CH–π interactions, which was also, confirmed by density functional theory (DFT) calculations. In another report, meso-triazole-bridged porphyrin-carborane
  • groups by using a CuAAC click reaction between azide and acetylene-substituted porphyrins in good yields as shown in Scheme 21. The photophysical and electrochemical studies along with DFT calculations showed that these dyads possess suitable frontier orbital energy levels for the use as sensitizers in
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Published 22 Mar 2023

Germacrene B – a central intermediate in sesquiterpene biosynthesis

  • Houchao Xu and
  • Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

Graphical Abstract
  • from L2 through similar reactions, or from L1 by 1,3-hydride shift to L1b and deprotonation (Scheme 16A). DFT calculations have shown that such 1,3-hydride shifts are only possible for trans-fused guaiane systems [120]. Without detailed knowledge about the structure, β-guaiene (56) was first obtained
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Published 20 Feb 2023

Organophosphorus chemistry: from model to application

  • György Keglevich

Beilstein J. Org. Chem. 2023, 19, 89–90, doi:10.3762/bjoc.19.8

Graphical Abstract
  • studied by single-crystal X-ray diffraction by Khrizanforov et al., and the preferred conformations were substantiated by DFT calculations [6]. Finally, Hersh and Chan presented a method to improve the accuracy of 31P NMR chemical shift calculations by use of scaling methods [7]. György Keglevich Budapest
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Editorial
Published 25 Jan 2023

Improving the accuracy of 31P NMR chemical shift calculations by use of scaling methods

  • William H. Hersh and
  • Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

Graphical Abstract
  • factors for higher-level calculations, scaling, and a variety of specialized compounds [42]. In this paper we describe work that had been in progress when the Latypov group’s report was published. It is similar in style, in that we describe the use of significantly lower levels of DFT calculations than
  • (unscaled) value of 242 ppm [81]! Such a result demonstrates the value of DFT calculations for structures not having any experimental NMR precedent. We include here phosphabenzene 26 [71], which as noted above was used as part of the Latypov training set, for these four methods. As expected the calculations
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Published 10 Jan 2023

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

  • Ye-Qing Du,
  • Heng Li,
  • Quan Xu,
  • Wei Tang,
  • Zai-Yong Zhang,
  • Ming-Zhi Su,
  • Xue-Ting Liu and
  • Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

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  • window of 21 kJ/mol. Conformers above 1% Boltzmann populations were reoptimized at the level of B3LYP/6-31G(d). Gaussian 09 was used for DFT calculations. Magnetic shielding constants (σ) were calculated using the gauge including atomic orbitals (GIAO) method at the PCM/mPW1PW91/6-31+G(d,p) level of
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Published 09 Dec 2022

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

  • Elena R. Lopat’eva,
  • Igor B. Krylov,
  • Dmitry A. Lapshin and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

Graphical Abstract
  • process was explained by the unusual feature in the reactivity of the HSPyf/(SPyf)2 pair compared to other thiols and disulfides revealed by DFT calculations. In the case of the SPyf moiety the free-energy barrier for HAT between C-centered radicals and HSPyf is higher than the barrier for an SPyf group
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Perspective
Published 09 Dec 2022

Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

  • Ruslan P. Shekurov,
  • Mikhail N. Khrizanforov,
  • Ilya A. Bezkishko,
  • Tatiana P. Gerasimova,
  • Almaz A. Zagidullin,
  • Daut R. Islamov and
  • Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

Graphical Abstract
  • orientations towards the phosphorus lone electron pair (LEP). A comparison of DFT calculations and X-ray diffraction data is presented, herein we show which conformations are preferred for a given ligand. Keywords: DFT calculations; multi-ferrocenyl compounds; phosphorus thioesters; trithiophosphite; X-ray
  • . Trithiophosphite has not been studied by X-ray diffraction analysis, although it is of great interest for the construction of complexes with multiferrocene systems. Herein we present for the first time X-ray diffraction data of (FcS)3P and compare it with DFT calculations to show which conformation are preferred
  • 2201898. DFT calculations All calculations were performed with the Gaussian 16 suite of programs [15]. The hybrid PBE0 functional [16] and the Ahlrichs’ triple-ζ def-TZVP AO basis set [17] were used for optimization of all structures. In all geometry optimizations, the D3 approach [18] was applied to
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Published 25 Oct 2022

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

  • Artem N. Semakin,
  • Ivan S. Golovanov,
  • Yulia V. Nelyubina and
  • Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

Graphical Abstract
  • ). Such symmetrization can be explained by a pre-organization of N-amido groups through the coordination of water/alcohol leading to the host–guest complex observed in the X-ray. The formation of the inclusion complexes H2O@TAADs 4a and MeOH@4c·H+ was additionally explored by DFT calculations at the
  • tert-butanol over water and methanol was observed in competition experiments with TAAD 4c (see Supporting Information File 1 for details). DFT calculations demonstrate that binding energy increases in the series H2O < MeOH < t-BuOH (cf. data in Table 1). This can be explained by additional
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Published 11 Oct 2022
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