Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

• Sergio Torres-Oya and
• Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

• -position of the activating group with good yields (52–98%), excellent diastereoselectivities and good enantioselectivities (76–94% ee). Additionally, to understand the mechanism of the reaction, the authors performed DFT calculations. Based on the calculations, once the dienolate is hydrolyzed to the free

• mechanism and the origin of the enantioselectivity, the authors performed DFT calculations, highlighting the importance of the outer phenyl ring of the chiral phosphoric acid on the enantioinduction. To demonstrate the synthetic applicability of the chiral axial derivatives a variety of transformations were

Synthesis of 2H-azirine-2,2-dicarboxylic acids and their derivatives

• Anastasiya V. Agafonova,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2024, 20, 3191–3197, doi:10.3762/bjoc.20.264

• not isomerize at room temperature, which is typical for highly sterically congested isoxazoles containing a 3-tert-butyl substituent [26]. The mechanism of such isomerizations of isoxazoles has been previously discussed using DFT calculations [25][26], which revealed the formation of an isoxazole–Fe

Direct trifluoroethylation of carbonyl sulfoxonium ylides using hypervalent iodine compounds

• Radell Echemendía,
• Carlee A. Montgomery,
• Fabio Cuzzucoli,
• Antonio C. B. Burtoloso and
• Graham K. Murphy

Beilstein J. Org. Chem. 2024, 20, 3182–3190, doi:10.3762/bjoc.20.263

• reactants. Finally, DFT calculations provided insights about the mechanism of this transformation, which strongly suggest that an SN2 reaction is operative. Keywords: alkylation; DFT calculations; fluorine chemistry; hypervalent iodine; sulfoxonium ylide; sulphur ylides; Introduction Introducing fluorine

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• chloropentafluorosulfanylated [2]staffane (SF5-BCP-BCP-Cl, 2), based on alternating radical polarity matching in the chain-propagation steps (Figure 1, bottom) [45][46][47]. Density functional theory (DFT) calculations provide insight into our observed selectivity, and our hypothesis is bolstered by computation of relative

• established that [1.1.1]propellane participates in radical-chain reactions (i.e., oligomerization) at room temperature in solution to form unsubstituted [n]staffanes. The origin of this innately controlled oligomerization was then investigated through density functional theory (DFT) calculations. The free

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• is then attacked by a nucleophile. The use of chiral iodine catalysts is essential for controlling the stereochemistry of the reaction. The specific arrangement of the catalyst influences the orientation of this nucleophilic attack as supported by density functional theory (DFT) calculations. In 2022

• up to 95% within a short time-frame of 10 minutes. Treatment of N-(2-phenylallyl)benzamides with 10 equivalents of BF3·Et2O, iodobenzene, m-CPBA in dichloromethane (DCM) at 0 °C resulted in the formation of the oxazoline product (Scheme 21). DFT calculations indicated several steps in the mechanism

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• , with TBAI as a co-catalyst, up to 74% yields (Table 1). The inactivity of porphyrin 18 was attributed to the inaccessibility of the inner core imine due to its planar structure. The mechanism of the epoxide ring-opening reaction was elucidated by DFT calculations, which suggested that the macrocycle

• (Table 5). DFT calculations predicted that the catalytically active species is the adduct of porphyrin and TBACl (18-I), which forms an activated complex (18-II) with the substrate followed by a ring-opening nucleophilic attack of Cl−. The electron-rich nitrogen atom in 18-III further activates

• zero due to too strong association of trifluoroacetate with protonated porphyrin. DFT calculations suggested that the O–O bond in O2 becomes polarized upon binding in {(H4TPP2+)·(TB−)·O2}, which facilitates

Enantioselective regiospecific addition of propargyltrichlorosilane to aldehydes catalyzed by biisoquinoline N,N’-dioxide

• Noble Brako,
• Sreerag Moorkkannur Narayanan,
• Amber Burns,
• Layla Auter,
• Valentino Cesiliano,
• Rajeev Prabhakar and
• Norito Takenaka

Beilstein J. Org. Chem. 2024, 20, 3069–3076, doi:10.3762/bjoc.20.255

• in the absence and presence of N,N-diisopropylethylamine using density functional theory (DFT) calculations (Figure 1). According to the DFT calculations, the free propargyltrichlorosilane (Iprop) can isomerize to allenyltrichlorosilane (Iall) with a prohibitively high barrier of 43.8 kcal/mol

Tailored charge-neutral self-assembled L₂Zn₂ container for taming oxalate

• David Ocklenburg and
• David Van Craen

Beilstein J. Org. Chem. 2024, 20, 3007–3015, doi:10.3762/bjoc.20.250

• sufficient quality to obtain a solid-state structure of the oxalate host–guest complex [(C2)@L2Zn2]2− so that we utilized DFT calculations to model the expected structure of the host–guest species (Figure 3a). Therefore, we funneled structural information obtained from NMR spectra into our starting geometry

gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

• Monika Bilska-Markowska,
• Marcin Kaźmierczak,
• Wojciech Jankowski and
• Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

• approximately 150° [42][43][44][45]. These data were consistent with DFT calculations (see Supporting Information File 1). The reaction of the amide 1d with n-BuLi resulted in a surprising outcome. In this case, product 9d and only traces of the expected product 10d were received, as indicated by the 19F NMR

• ]. These findings are in alignment with DFT calculations (see Supporting Information File 1) and corroborate data for compounds 9a–d. We further decided to use tert-BuLi in our research, considering its role as a stronger base and simultaneously as a weak nucleophile. We first performed the reaction with 2

• experimental procedures, DFT calculations, characterization data, and copies of 1H, 13C, 19F NMR and 1H−13C HSQC spectra. Acknowledgements The calculations were performed in the Poznan Supercomputing and Networking Center.

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

• the Knoevenagel condensation with malononitrile was successfully reported [33]. Theoretical studies Density functional theory (DFT) calculations of two derivatives of compounds 2 and 3, having methoxy groups instead of the longer alkyl chains have been reported in the literature [32], providing

• hindered charge transport. Experimental Computational Density functional theory (DFT) calculations were performed using Gaussian 09 software. Molecular geometries were initially optimised semi-empirically (AM1) and then reoptimised by DFT using the B3LYP method with the 6-311G(d,p) basis set unless stated

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• aryl sulfides 85 from thiols 84 using diaryliodonium salts 16 in basic conditions (Scheme 34). A multitude of thiols and diaryliodonium salts was examined in the reaction under optimized conditions, yielding exceptional yields [88]. To embrace the chemical process, DFT calculations were performed in

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• -β-41a (55%) and E-β-41a (41%) are in accordance with the relative thermodynamic stability of the two geometric isomers. According to DFT calculations, the Z-isomer is slightly energetically favored by 14.88 kJ/mol. The configurations were determined by comparison of chemical shifts of our products

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• 2 and 3, the minimum energy paths (MEPs) of these processes were calculated. Quantum chemical DFT calculations were performed using the B3LYP/6-311++G(d,p) basis set and taking into account solvation effects using the polarizable continuum model (PCM). Interactions of 1 with N-phenylmaleimide (2a

• ). Conclusion Thus, we have proposed an efficient way to construct tetrahydroimidazo[1,2-a]pyrimidines without substituents at the 4 and 5-positions of the imidazole fragment by the reaction of 2-aminoimidazole with N-arylitaconimides and N-substituted maleimides. With the aid of DFT calculations, the most

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• ). Further control experiments and DFT calculations show that during the catalytic process, tertiary amine directly participates as a nucleophilic reagent to give the ammonium salt, which then releases dimethylaminium to provide the final product (Scheme 12). Chiral allylic sulfone compounds can be easily

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

• properties of γ-CD (the largest of the three most abundant native CDs), the main experimental methods applied in this study were differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). By coupling these techniques with density functional theory (DFT) calculations we try to shed some

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• ]. In each structure, the non-hydrogen atoms were refined anisotropically. CIF files (CCDC-2364292–2364296) can be obtained free of charge from the Cambridge Crystallographic Data Centre via https://www.ccdc.cam.ac.uk/data_request/cif. DFT calculations. DFT calculations for the geometrical optimizations

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

• of molecules using density functional theory (DFT) calculations, which are computationally expensive and time-consuming [62]. To overcome this challenge, some studies have proposed to pre-generate QM properties datasets and train ML models to serve as fast feature generators for new molecules [16

• ]. However, this approach requires careful validation of the training data coverage and the extrapolation ability of the surrogate models. Reaction-level descriptors based on DFT calculations of the TS structures of chemical reactions can provide valuable insights for predicting rate constants [113][114][115

Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols

• Smaher E. Butt,
• Konrad Kepski,
• Jean-Marc Sotiropoulos and
• Wesley J. Moran

Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209

• -cyclization onto the alkene when n = 3, we modelled this reaction using DFT calculations (Scheme 2). Similarly, we concluded that the present reaction commences with activation of the olefin in 3a by the hypervalent iodine species 8, which is generated under the reaction conditions. The activation occurs via

• ring. We have performed DFT calculations to support the proposed change in mechanism and developed superior reaction conditions to effect this transformation. Finally, we have explored the substrate scope of this cyclization. Functional molecules containing a substituted pyrrolidine core. A) Our

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

• and nonbonding interactions for the halogen at C4. Finally, density functional theory (DFT) calculations corroborate the preference of talose analogues to adopt a 4C1-like conformation and a natural bonding orbital (NBO) analysis demonstrates the effects of hyperconjugation from C–F antibonding

• ) [24]. The solution and the solid-state conformational analysis were supplemented with DFT calculations to understand key conformational drivers. This study adds more data to the field of nuclear magnetic resonance (NMR) spectroscopy of polyhalogenated molecules. It should be noted that the NMR

• -halides motivated us to use density functional theory (DFT) calculations to understand the preference of talose analogues to adopt 4C1-like conformations. DFT computations were performed using Gaussian 16 revision B.01 [67] with the CAM-B3LYP [68][69][70] functional and the Def2TZVP basis set [71], which

Synthesis and reactivity of the di(9-anthryl)methyl radical

• Tomohiko Nishiuchi,
• Kazuma Takahashi,
• Yuta Makihara and
• Takashi Kubo

Beilstein J. Org. Chem. 2024, 20, 2254–2260, doi:10.3762/bjoc.20.193

• two anthryl moieties (Figure 3b, Supporting Information File 1, Figure S1). DFT calculations for structural optimization revealed that the energy difference between two DAntM radical structures with different spin positions, spin localization at the central sp2 carbon and on the anthryl group, is

• Figure 6a and 6b, respectively. The DAntM radical exhibited a forbidden near-IR (NIR) band centered at 900 nm and relatively intense bands at 580 and 540 nm, whose spectral pattern is similar to the spectrum pattern of the TAntM radical [17]. The result of TD-DFT calculations could reproduce the obtained

Metal-free double azide addition to strained alkynes of an octadehydrodibenzo[12]annulene derivative with electron-withdrawing substituents

• Naoki Takeda,
• Shuichi Akasaka,
• Susumu Kawauchi and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2024, 20, 2234–2241, doi:10.3762/bjoc.20.191

• substituents has a lower Ea than DBA with electron-donating substituents. DFT calculations The reaction mechanism was investigated by computational calculations. The reaction mechanism between 5 and benzyl azide was supported by the ωB97X-D/6-31G(d,p) calculations with the CH2Cl2 polarizable continuum model

• previously reported electron-donating hexyloxy substituents. The addition pattern was experimentally investigated by 2D NMR, which was also supported by DFT calculations. The bistriazole product displayed fluorescence in the visible range with a fluorescence quantum yield of 7.0%. Finally, the developed

• recorded on a JASCO FP-8500. All calculations were carried out using the Gaussian 16 program [21]. The DFT calculations were carried out using the long-range and dispersion-corrected ωB97X-D functional [22]. The 6-31G(d,p) basis set was used for H, C, O, and S atoms [23][24]. The solvent effect of CH2Cl2

Heterocycle-guided synthesis of m-hetarylanilines via three-component benzannulation

• Andrey R. Galeev,
• Maksim V. Dmitriev,
• Alexander S. Novikov and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2024, 20, 2208–2216, doi:10.3762/bjoc.20.188

• Russian Federation (FSNF-2023-0004). The DFT calculations were supported by the RUDN University Scientific Projects Grant System, project № 021342-2-000.

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

Radical reactivity of antiaromatic Ni(II) norcorroles with azo radical initiators

• Siham Asyiqin Shafie,
• Ryo Nozawa,
• Hideaki Takano and
• Hiroshi Shinokubo

Beilstein J. Org. Chem. 2024, 20, 1967–1972, doi:10.3762/bjoc.20.172

• ) norcorrole. The radical reactivity of Ni(II) norcorroles was investigated by density functional theory (DFT) calculations. Keywords: 16π; antiaromatic; norcorrole; porphyrinoid; radical; Introduction Considerable attention has been directed toward antiaromatic norcorroles [1][2][3] due to the fascinating

• presented. We also discuss the selectivity of the radical addition to Ni(II) norcorroles using DFT calculations. Results and Discussion Reactivity with azo radical initiators We selected 2,2'-azobis(isobutyronitrile) (AIBN) as a radical source. Ni(II) dimesitylnorcorrole 1 was treated with AIBN in refluxing

• 2a obtained by TD DFT calculations at the M06/6-31G(d)+SDD//B3LYP-D3/6-31G(d)+SDD level of theory was consistent with the experimental results. Therein, the absorption band at 670 nm (f = 0.0026) was attributed to the transition from HOMO to LUMO+1. Next, the electrochemical properties of 2a in

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• -carboxylate (6) and the use of density functional theory (DFT) to evaluate their mechanisms. Over thirty N1- and N2-alkylated products were isolated in over 90% yield regardless of the conditions. DFT calculations suggest a chelation mechanism produces the N1-substituted products when cesium is present and

• isolated in >99% yield under conditions B albeit with low conversion. Both conditions provided >98:2 regioselectivity for their respective major products as determined by LC–MS. We again turned to DFT calculations to explore the mechanisms of these reactions and found very similar results to the parent

• the major regioisomer regardless of which conditions were employed. Though separation of products was challenging, resulting in a lower isolated yield under conditions B, the regioselectivity was greater than 99:1 under both conditions. DFT calculations again showed the deprotonated analog of 21 to be