Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• and 6. Relative stability of the tautomers 7 and 7a,b of quinoxaline[2,3-b]phenoxazine calculated at the DFT B3LYP/6-311++G(d,p) level. Preparation of quinoxaline[2,3-b]phenoxazine (7) from 2-amino-3H-phenoxazin-3-one (8) [10] and 2-ethoxy-3H-phenoxazin-3-one (9) [11], respectively. Triphenodioxazine

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

• the 1H,13C-HSQC and 1H,13C-HMBС spectra, as well as by comparing the experimental carbon chemical shifts in DMSO-d6 with those calculated for 6 by the GIAO method at the PBE1PBE/6-311+G(2d,p) level of theory using the DFT B3LYP/6-311++G(d,p) optimized geometries (DMSO solution) and applying a multi

• the PBE1PBE/6-311+G(2d,p) level of theory using the DFT B3LYP/6-311++G(d,p) optimized geometries (DMSO solution) and applying a multi-standard approach [44]. The calculated shifts of sp2-atoms C-7a, C-4, C-6, C-3, and C-3a in (Z)-8 and the s-cis-conformer (with respect to the C4–N bond) of 9 were

• 156.6, 152.1, 151,9, 128.3, 105.6 ppm and 160.9, 158.9, 157.4, 123.3, 98.4 ppm, respectively. The corresponding experimental shifts (155.0, 151.8, 149.9, 128.4, 105.4 ppm) were in good agreement with the structure 8. It is noteworthy that the DFT B3LYP/6-311++G(d,p) calculations using the PCM solvation

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

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

• >C=P– or –N=P– functionality present in these compounds towards 1,3-butadiene. Results and Discussion We investigated the following model DA reactions (Table 1) at the DFT (B3LYP/6-31+G (d)) level of theory. The values of the energies of the frontier molecular orbitals (FMOs) global hardness (η

An isoxazole strategy for the synthesis of 4-oxo-1,4-dihydropyridine-3-carboxylates

• Timur O. Zanakhov,
• Ekaterina E. Galenko,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2022, 18, 738–745, doi:10.3762/bjoc.18.74

• intermediate 3, as shown for the reaction of isoxazole 1g (Scheme 2). Taking into account that compounds 2 can potentially exist in pyridone and pyridole tautomeric forms, we performed calculations at the DFT B3LYP-D3/6-311+G(d,p) level of theory with SMD solvent model to evaluate this tautomeric equilibrium

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• equilibrium between A and B using semiempirical calculations (AM1 and PM3) and DFT (B3LYP/6-31G(d)) in the gas phase and water, where it was observed that in the gas phase B is the most stable, while in water A is formed, which is in agreement with the experimental results reported in the literature. There

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• molecules have been examined. Additionally, theoretical studies based on density functional theory (DFT/B3LYP/6-31G(d)) were carried out. Keywords: alkynes; catalysis; cross-coupling; heterocycles; palladium; Introduction The development and design of small π-conjugated molecules have attracted increasing

Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts

• Kenta Tanaka,
• Yuta Tanaka,
• Mami Kishimoto,
• Yujiro Hoshino and
• Kiyoshi Honda

Beilstein J. Org. Chem. 2019, 15, 2105–2112, doi:10.3762/bjoc.15.208

• examined using MeCN, CH3NO2, DMSO and MeOH, no substantial shifts of the main peak at around 460 nm in the UV–vis absorption spectra were observed [24], indicating that the main absorption of these catalysts would be due to π–π* transition, which is supported by DFT calculations (TD-DFT B3LYP method

Selective detection of DABCO using a supramolecular interconversion as fluorescence reporter

• Indrajit Paul,
• Debabrata Samanta,
• Sudhakar Gaikwad and
• Michael Schmittel

Beilstein J. Org. Chem. 2019, 15, 1371–1378, doi:10.3762/bjoc.15.137

• were established through 1H NMR (Figure 4) and UV–vis spectra (Figure 3b). DFT (B3LYP/6-31G(d)) calculations on rectangle 5 and sandwich complex 6 allow the modeling of the supramolecular architecture and provide some structural insights. The DFT computations demonstrate that the sandwich complex is

Influence of per-O-sulfation upon the conformational behaviour of common furanosides

• Alexey G. Gerbst,
• Vadim B. Krylov,
• Dmitry A. Argunov,
• Maksim I. Petruk,
• Arsenii S. Solovev,
• Andrey S. Dmitrenok and
• Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2019, 15, 685–694, doi:10.3762/bjoc.15.63

• mechanical calculations. All the mentioned changes certainly affect the values of the intraring 1H–1H coupling constants. To study this influence in detail, DFT/B3LYP/pcJ-1 calculation of the constants for low-energy conformers (A–M) denoted in Table 4 was performed (Table 6). The first thing to note is that

• . Coupling constants were computed using DFT/B3LYP/pcJ-1 [33] approximation and DALTON-2015 software [34]. Only Fermi-contact terms were evaluated. Synthesis of propyl α-D-mannofuranoside (1) To a suspension of D-mannose (400 mg, 2.22 mmol) in n-propanol (4 mL) was added resin IR-120(H+) (475 mg). The

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• the positively charged macrocycles a quantum chemical study of the 10a complexes with ATP and ADP has been carried out. For calculations, the Gaussian 09 program with the DFT/B3LYP method based on the 6-311g basis set with CPCM solvation model with water as the solvent was used [47]. The energy of

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• quantum chemical calculations (DFT/B3LYP-6-31G*) [81] steric effects were identified as the main factor influencing the ratio of both regioisomers. These calculations clearly proved the almost apolar character of both possible transition states giving 3- and 4-BPin substituted pyrazoles through bicyclic

A permutation approach to the assignment of the configuration to diastereomeric tetrads by comparison of experimental and ab initio calculated differences in NMR data

• Przemysław J. Boratyński

Beilstein J. Org. Chem. 2017, 13, 2478–2485, doi:10.3762/bjoc.13.245

• geminal hydrogens were arranged by their chemical shifts. The computed geometries were all optimized at DFT/B3LYP/6-31G(d,p) in vacuum and GIAO calculations were performed at the same level of theory but including polarizable continuum solvent model (PCM) for chloroform utilizing Gaussian code [16]. The

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• optimized by using the DFT B3LYP/6-311G(2df,p) method. Energies of the HOMO and the LUMO, their differences and ground-state dipole moments μ were calculated on the DFT B3LYP/6-311++G(2df,p) level (Table 1). Second hyperpolarizabilities were calculated by using the PM7 semi-empirical method implemented in

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• experimental results were rationalized by a computational study performed at the DFT B3LYP/6-31G(d) level of theory with the PCM solvation model [39]. The thermal [3 + 2]-cycloadditions of azomethine ylides derived from diethyl cis- and trans-1-(4-methoxyphenyl)aziridine-2,3-dicarboxylates with E-1b led to

Regiochemistry of cyclocondensation reactions in the synthesis of polyazaheterocycles

• Patrick T. Campos,
• Leticia V. Rodrigues,
• Andrei L. Belladona,
• Caroline R. Bender,
• Juliana S. Bitencurt,
• Fernanda A. Rosa,
• Davi F. Back,
• Helio G. Bonacorso,
• Nilo Zanatta,
• Clarissa P. Frizzo and
• Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 257–266, doi:10.3762/bjoc.13.29

• other hand, the reaction of glyoxalates with amidines did not lead to the formation of imidazolones, but rather N-acylated products were obtained. All the products were isolated in good yields. DFT-B3LYP calculations provided HOMO/LUMO coefficients, charge densities, and the stability energies of the

• intermediates, and from these data it was possible to explain the regiochemistry of the products obtained. Additionally, the data were a useful tool for elucidating the reaction mechanisms. Keywords: DFT-B3LYP; polyazaheterocycles; pyrazinone; pyrido[1,2-a]pyrimidinone; pyrimido[1,2-a]benzimidazole

• reactions [15][16]. The main objective of this work has been the synthesis of a series of polyazaheterocycles through cyclocondensation reactions between a β-enaminodiketone and several 1,3-dinucleophiles. Due to the versatility of the precursors, a wide range of compounds was expected. Hence, DFT-B3LYP

Thiazol-4-one derivatives from the reaction of monosubstituted thioureas with maleimides: structures and factors determining the selectivity and tautomeric equilibrium in solution

• Alena S. Pankova,
• Pavel R. Golubev,
• Alexander F. Khlebnikov,
• Alexander Yu. Ivanov and
• Mikhail A. Kuznetsov

Beilstein J. Org. Chem. 2016, 12, 2563–2569, doi:10.3762/bjoc.12.251

• monosubstituted thioureas 1a–f with maleimides 2a–e. Reaction of monoalkylthioureas 1d–f with N-phenylmaleimide (2a) at room temperature. Relative Gibbs free energies of the optimized conformations of model thiazolidines, ΔG (kcal/mol) [DFT B3LYP/6-31+G(d,p)), 298 K, DMSO (PCM)]. Supporting Information

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• oligophenothiazines [45]. With these geometry-optimized structures in hand the electronic absorptions were calculated with the semiempirical ZINDO-CI, and TD-DFT (B3LYP and CAM-B3LYP, an implemented hybrid exchange-correlation functional [81], using the polarizable continuum model (PCM) [82] applying dichloromethane

• oligophenothiazines 3a, 3b, and 3c, computed UV–vis spectra of ZINDO-CI and TD-DFT (B3LYP, CAM-B3LYP) calculated structures of 3a, 3b, and 3c, computed FMOs (frontier molecular orbitals) of the calculated structures 3a, 3b, and 3c. Supporting Information File 272: Experimental and analytical data. Acknowledgements

Fe(II)/Et₃N-Relay-catalyzed domino reaction of isoxazoles with imidazolium salts in the synthesis of methyl 4-imidazolylpyrrole-2-carboxylates, its ylide and betaine derivatives

• Ekaterina E. Galenko,
• Olesya A. Tomashenko,
• Alexander F. Khlebnikov,
• Mikhail S. Novikov and
• Taras L. Panikorovskii

Beilstein J. Org. Chem. 2015, 11, 1732–1740, doi:10.3762/bjoc.11.189

• and phenacylimidazolium bromides 9 under FeCl2·4H2O/Et3N catalysis. The preparation of ylides 2 and imidazolethiones 13. Relative free energies (carbene 3/ylide 2, ylide 4/betaine 6 and carbene 5/betaine 6) computed at the DFT B3LYP/6-31+G(d,p) level in the gas phase or with the PCM model for the

Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium–zinc base and regioselectivity-computed CH acidity relationship

• Mohamed Yacine Ameur Messaoud,
• Ghenia Bentabed-Ababsa,
• Madani Hedidi,
• Aïcha Derdour,
• Floris Chevallier,
• Yury S. Halauko,
• Oleg A. Ivashkevich,
• Vadim E. Matulis,
• Laurent Picot,
• Valérie Thiéry,
• Thierry Roisnel,
• Vincent Dorcet and
• Florence Mongin

Beilstein J. Org. Chem. 2015, 11, 1475–1485, doi:10.3762/bjoc.11.160

• using the DFT B3LYP method in order to rationalize the experimental results. Keywords: CH acidity; indoles; iodolysis; mixed lithium–zinc bases; pyrroles; Introduction Pyrrole occurs in very important natural products such as tetrapyrrolic (linear) bilirubinoids, and (cyclic) porphyrins and corrins

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• at 314 and 405 nm. In the ECD spectra of (+)/(−)-3, the Cotton effect was observed over the entire absorption range. A simulated spectrum of 3 with the (R)-configuration, calculated by TD-DFT (B3LYP/6-31G(d,p)), has moderate resemblance to the spectrum obtained from (−)-3. This result is also

Gold-catalyzed formation of pyrrolo- and indolo-oxazin-1-one derivatives: The key structure of some marine natural products

• Sultan Taskaya,
• Nurettin Menges and
• Metin Balci

Beilstein J. Org. Chem. 2015, 11, 897–905, doi:10.3762/bjoc.11.101

• calculations performed in the gase phase showed that 6 is about 10.6 kcal/mol (DFT, B3LYP at 6-31G** level) and 8.1 kcal/mol (HF/6-311G** level) more stable than 7 (Figure 3). However, in the case of 30 and 31, we also found that the endo-cyclic isomer 31 is thermodynamically about 4.8 kcal/mol (DFT, B3LYP at

Trifluoromethyl-substituted tetrathiafulvalenes

• Olivier Jeannin,
• Frédéric Barrière and
• Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

• energy absorption maximum λmax (nm) and molar extinction coefficient ε (L·mol−1·cm−1) are determined in CH2Cl2 unless otherwise specified). Calculated (TD-DFT, B3LYP/6-311G**) optical transitions in the model compounds TTF, TTF–CF3, TTF–CO2Me and TTF–CN, and comparison with the experimentally determined

Azirinium ylides from α-diazoketones and 2H-azirines on the route to 2H-1,4-oxazines: three-membered ring opening vs 1,5-cyclization

• Nikolai V. Rostovskii,
• Mikhail S. Novikov,
• Alexander F. Khlebnikov,
• Galina L. Starova and
• Margarita S. Avdontseva

Beilstein J. Org. Chem. 2015, 11, 302–312, doi:10.3762/bjoc.11.35

• DFT B3LYP/6-31+G(d,p) calculations, the cycloaddition of dihydroazireno[2,1-b]oxazoles to acetyl(methyl)ketene, leading to the final bicyclic products, proceeds via consecutive low barrier formation of two pairs of atropoisomeric betaine intermediates followed by their cyclization. The reaction of 2,3

• compounds 6f and 7h. Energy profiles [DFT B3LYP/6-31+G(d,p), 357 K, 1,2-dichloroethane (PCM)] for the transformation of ylide 9j into azadiene 3j and dihydroazireno[2,1-b]oxazole 10j and for the transformation of 10j to adducts 6j,7j. X-ray crystal structure of compound 17. Rh(II)-catalyzed synthesis of

Pyrrolidine nucleotide analogs with a tunable conformation

• Lenka Poštová Slavětínská,
• Dominik Rejman and
• Radek Pohl

Beilstein J. Org. Chem. 2014, 10, 1967–1980, doi:10.3762/bjoc.10.205

• (C2’,P) in rotamer B should be observed. In order to support this assumption, we calculated 3J(C,P) of the most stable conformers (see the chapter Conformational analysis) of the adenine derivatives 13 and 14 for both A and B rotamers using the DFT B3LYP/6-31++G* method. The results summarized in

• pathway in 18-degree steps with constant maximum puckering amplitude of 40 degrees. For each conformer, the endocyclic torsion angles Φ0 and Φ3 were kept fixed and the geometry of the molecule was optimized using the DFT B3LYP/6-31G* method in vacuo. Predominant conformations can be found as the energy