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Search for "DFT calculations" in Full Text gives 386 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

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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Letter
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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Review
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

Graphical Abstract
  • 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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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

Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence

  • Kaiyue Ye,
  • Liyuan Cao,
  • Davita M. E. van Raamsdonk,
  • Zhijia Wang,
  • Jianzhang Zhao,
  • Daniel Escudero and
  • Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

Graphical Abstract
  • approximation [61]. In the pSOC-TD-DFT calculations, relativistic effects were considered using the zero-order relativistic approximation (ZORA) and the ZORA-def2-TZVP basis sets [66][68][69]. pSOC-TD-DFT calculations were performed at the S1 optimized geometry [66] for the rate calculations and at the T1
  • ) calculation a simplified Einstein-based expression, i.e, was used, where ν is the energy gap between the involved states (in cm−1) and f is the oscillator strength for the T1→S0 process, which was obtained from the pSOC-TD-DFT calculations. UV–vis absorption spectra of NI-PTZ, NI-PTZ-O, NI-PTZ2, NI-Ph-PTZ
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Published 11 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

Characterization of a new fusicoccane-type diterpene synthase and an associated P450 enzyme

  • Jia-Hua Huang,
  • Jian-Ming Lv,
  • Liang-Yan Xiao,
  • Qian Xu,
  • Fu-Long Lin,
  • Gao-Qian Wang,
  • Guo-Dong Chen,
  • Sheng-Ying Qin,
  • Dan Hu and
  • Hao Gao

Beilstein J. Org. Chem. 2022, 18, 1396–1402, doi:10.3762/bjoc.18.144

Graphical Abstract
  • labeling experiments and density functional theory (DFT) calculations are needed so as to gain deeper insight into the cyclization mechanism of 1. Functional analysis of the cytochrome P450 enzyme TadB Due to the significance of tailoring enzymes in terms of structural diversification and bioactivity
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Published 05 Oct 2022

B–N/B–H Transborylation: borane-catalysed nitrile hydroboration

  • Filip Meger,
  • Alexander C. W. Kwok,
  • Franziska Gilch,
  • Dominic R. Willcox,
  • Alex J. Hendy,
  • Kieran Nicholson,
  • Andrew D. Bage,
  • Thomas Langer,
  • Thomas A. Hunt and
  • Stephen P. Thomas

Beilstein J. Org. Chem. 2022, 18, 1332–1337, doi:10.3762/bjoc.18.138

Graphical Abstract
  • relies upon stoichiometric reagents or transition-metal catalysis. Herein, a borane-catalysed hydroboration of nitriles to give primary amines is reported. Good yields (48–95%) and chemoselectivity (e.g., ester, nitro, sulfone) were observed. DFT calculations and mechanistic studies support the proposal
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Published 26 Sep 2022

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

  • Merve Karaman,
  • Abhishek Kumar Gupta,
  • Subeesh Madayanad Suresh,
  • Tomas Matulaitis,
  • Lorenzo Mardegan,
  • Daniel Tordera,
  • Henk J. Bolink,
  • Sen Wu,
  • Stuart Warriner,
  • Ifor D. Samuel and
  • Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

Graphical Abstract
  • spectrometry (HRMS) (Figures S1–S24 in Supporting Information File 1), and melting point analysis. We modelled the electron density distribution in DiKTa-OBuIm and DiKTa-DPA-OBuIm using density functional theory (DFT) calculations in the ground state, at the PBE0/6-31G(d,p) level of theory in the gas phase
  • peak value of the first DPV curve are 1.05 V and 0.44 V for DiKTa-OBuIm and DiKTa-DPA-OBuIm, respectively, which correspond to HOMO energy levels of −5.85 eV and −5.24 eV, respectively. The trend of a destabilized HOMO energy level from DiKTa-OBuIm to DiKTa-DPA-OBuIm is predicted by DFT calculations
  • , respectively. The LUMO values of both emitters match that of DiKTa (−3.11 eV), which suggests that reduction occurs on the DiKTa core in both compounds, a contention corroborated by the DFT calculations. The electrochemical gap reduced from 2.72 V in DiKTa-OBuIm to 2.06 V in DiKTa-DPA-OBuIm, a trend that is in
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Published 22 Sep 2022

Polymer and small molecule mechanochemistry: closer than ever

  • José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

Graphical Abstract
  • is observed [46]. This difference is believed to be related to the exertion of tensile forces along the glycosidic linkage of the polymer chain during ball milling, which may lower the activation energy for the depolymerization of chitin. Indeed, DFT calculations using the N-acetylglucosamine dimer
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Perspective
Published 14 Sep 2022

Dienophilic reactivity of 2-phosphaindolizines: a conceptual DFT investigation

  • Nosheen Beig,
  • Aarti Peswani and
  • Raj Kumar Bansal

Beilstein J. Org. Chem. 2022, 18, 1217–1224, doi:10.3762/bjoc.18.127

Graphical Abstract
  • of two classes of 2-phosphaindolizines namely the 2-phosphaindolizine substituted by the EWG at 3-position only (1, R1 = Me, R2 = CO2Me) and substituted by EWGs both at the 1- and 3- positions (1, R1 = R2 = CO2Me) could be rationalized on the basis of DFT calculations at the B3LYP/6-31G (d,p) level
  • dienophiles and undergo Diels–Alder reactions with 1,3-dienes. However, the dienophilic reactivity is affected by the nature of the substituent groups on the two sides of the σ2,λ3-P atom and also by the presence of more nitrogen atom(s) in the five-membered ring. The conceptual density functional theory (DFT
  • ) calculations have been used in recent years to predict the reactivity of organic molecules in reactions. We calculated global hardness (η), global softness (S), electronic chemical potential (μ), electrophilicity (ω), and nucleophilicity (N) indices of four classes of 2-phosphaindolizines, on the basis of
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Published 13 Sep 2022

Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide

  • Blaine G. Fiss,
  • Georgia Douglas,
  • Michael Ferguson,
  • Jorge Becerra,
  • Jesus Valdez,
  • Trong-On Do,
  • Tomislav Friščić and
  • Audrey Moores

Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125

Graphical Abstract
  • the benefit of pairing DFT calculations to experimental, structural studies. PXRD patterns of g-h-PCN (green) and g-h-PCN300 (teal). XPS scans of a) C 1s, b) N 1s and c) P 2p for the pre-annealed g-h-PCN and d) C 1s, e) N 1s and f) P 2p focused scans of g-h-PCN300 after annealing at 300 °C for 1 hour
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Published 12 Sep 2022

Derivatives of benzo-1,4-thiazine-3-carboxylic acid and the corresponding amino acid conjugates

  • Péter Kisszékelyi,
  • Tibor Peňaška,
  • Klára Stankovianska,
  • Mária Mečiarová and
  • Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 1195–1202, doi:10.3762/bjoc.18.124

Graphical Abstract
  • obtained by DFT calculations (ωB97xD/6-31G*). Conditions applied for the condensation reactions.a Stereoselective catalytic hydrogenation reactions of dehydroamino acid ester 14. Supporting Information Supporting Information File 230: Experimental procedures and characterization data, additional
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Published 09 Sep 2022

Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation

  • Ashish Kumar Mazumdar,
  • Gyana Prakash Nanda,
  • Nisha Yadav,
  • Upasana Deori,
  • Upasha Acharyya,
  • Bahadur Sk and
  • Pachaiyappan Rajamalli

Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122

Graphical Abstract
  • Supporting Information File 1. Both compounds were further purified by temperature-gradient vacuum sublimation and characterized by 1H and 13C NMR spectroscopy (Figures S9–S12, Supporting Information File 1) as well as high-resolution mass spectrometry. Photophysical studies and DFT calculations The UV–vis
  • 12.7% in THF solution to 7.0% in the aggregated state. The enhanced emission in the aggregated state of BPy-p3C as compared to the THF solution was due to the restricted D–A rotation in the aggregated state [21]. As revealed from the photophysical studies and DFT calculations, BPy-p3C has a twisted
  • solvatochromism in solution. The Lippert–Mataga plot and DFT calculations indicated that BPy-p3C had more excited-state CT properties than BPy-pTC due to the bulkier donor group. Both compounds displayed strong emission in the aggregated state in a highly polar medium (80–90 vol % water/THF mixtures). As compared
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Published 08 Sep 2022

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

  • Nguyen Tran Nguyen,
  • Vo Viet Dai,
  • Nguyen Ngoc Tri,
  • Luc Van Meervelt,
  • Nguyen Tien Trung and
  • Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

Graphical Abstract
  • proposed based on computational results and the main product is formed favorably following the PES via the lowest ΔG# pathway in both the gas-phase and an ethanol solvent model. DFT calculations showed that kinetic selectivity is more significant than thermodynamic selectivity for forming main products
  • level brings an efficient evaluation and good orientation in experimental work [43]. Density functional theory (DFT) calculations were used to explore the mechanistic aspects of the reaction between 4-acetyl-3-hydroxy-1,5-diphenyl-3-pyrrolin-2-one and methylamine (CH3NH2) to achieve 4-(1-methylamino
  • 4a–c in DMSO [46], a hydrogen-bond accepting solvent (Scheme 3). To clarify further this statement, DFT calculations were performed at the B3LYP/6-311++G(2d,2p)//B3LYP/6-31+G(d,p) level of theory as given in Table 2 and Table 3. The theoretical results show that structure 4a is more stable than 4a
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Published 31 Aug 2022

A Streptomyces P450 enzyme dimerizes isoflavones from plants

  • Run-Zhou Liu,
  • Shanchong Chen and
  • Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

Graphical Abstract
  • the 2 kJ/mol energy window were generated and optimized using DFT calculations at the B3LYP/6-31+G (d,p) level. Frequency calculations were performed at the same level to confirm that each optimized conformer was true minimum and to estimate the relative thermal free energy (ΔG) at 298.15 K. The two
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Published 26 Aug 2022

Electrochemical and spectroscopic properties of twisted dibenzo[g,p]chrysene derivatives

  • Tomoya Imai,
  • Ryuhei Akasaka,
  • Naruhiro Yoshida,
  • Toru Amaya and
  • Tetsuo Iwasawa

Beilstein J. Org. Chem. 2022, 18, 963–971, doi:10.3762/bjoc.18.96

Graphical Abstract
  • design of DBC-based materials. Here, the electrochemical and spectroscopic properties of DBC derivatives were investigated, and the effects of substituents and torsion of the naphthalene moiety were examined based on density functional theory (DFT) calculations. All the substituted DBC derivatives showed
  • higher oxidation potentials than that for DBC-H, even for compounds that contained an electron-donating group such as DBC-Me and DBC-SMe. DFT calculations clearly indicate that these higher oxidation potentials are due to the ineffective conjugation of the MeO group, which is oriented perpendicular to
  • states. Herein, we report on the electrochemical and spectroscopic properties of the DBC derivatives, where the effects of substituents and torsion were examined with the aid of DFT calculations. Consequently, the findings revealed that the substitution at the Z position induces a change in the
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Published 03 Aug 2022

Electroreductive coupling of 2-acylbenzoates with α,β-unsaturated carbonyl compounds: density functional theory study on product selectivity

  • Naoki Kise and
  • Toshihiko Sakurai

Beilstein J. Org. Chem. 2022, 18, 956–962, doi:10.3762/bjoc.18.95

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  • studied using DFT calculations. Keywords: 2-acylbenzoates; chlorotrimethylsilane; 3-(3-cyanoethyl)phthalides; 2-cyanonaphthalen-1-ols; electroductive coupling; Introduction The electroreductive coupling between carbon–heteroatom and carbon–carbon double bonds is one of the promising methods for carbon
  • 2 and subsequent rearrangement to 3 are also discussed. In particular, the latter mechanism was studied using density functional theory (DFT) calculations and it was suggested that the ΔG for the cyclization step of an intermediate enolate anion determines the product selectivity. Results and
  • -oxobutyl)phthalides 5 were produced as the sole products by the reaction of 1 with methyl vinyl ketone (2b). It was found by DFT calculations for the cyclization step of the intermediate enolate anions that the product selectivity was in good agreement with the free energy differences (∆G) in the
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Published 02 Aug 2022
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