Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

• density functional theory, the temperature-dependent swelling behavior of a polymer brush could be simulated in comparison to the corresponding phase diagrams of the free, unbound polymer chains in solution [124]. The corresponding diagrams are summarized in Figure 7 and show the typical thickness

Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions

• Susanne M. Fischer,
• Simon Renner,
• A. Daniel Boese and
• Christian Slugovc

Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117

• radical cations of the phosphines under investigation were calculated by density functional theory (DFT), namely B3LYP-def2-TZVPPD. According to criterion introduced by Stewart et al. postulating air stability of phosphines when the SOMO energy is higher than −10 eV, the three derivatives should be air

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

• . In order to elucidate these experimental observations, quantum chemical calculations based on density functional theory (DFT) methodology were performed. The estimated visualization of highest occupied and lowest unoccupied molecular orbitals, as well as the molecular electrostatic potential (MEP) of

• equilibrium conformer at ground state was first found at AM1 level. Then, further optimizations through density functional theory (DFT) approach [73] at the restricted Becke3–Lee–Yang–Parr hybrid functional (B3LYP) with standard basis set 6-31G were carried out. Experimental procedure and spectroscopic data

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

Structural effects of meso-halogenation on porphyrins

• Keith J. Flanagan,
• Maximilian Paradiz Dominguez,
• Zoi Melissari,
• Hans-Georg Eckhardt,
• René M. Williams,
• Dáire Gibbons,
• Caroline Prior,
• Gemma M. Locke,
• Alina Meindl,
• Aoife A. Ryan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

• . Additionally, we have used density functional theory calculations to determine the structure of several halogenated porphyrins. This contrasts conformational analysis with existing X-ray structures and gives a method to characterize samples that are difficult to crystallize. By using the methods outlined above

• formation of the crystal networks. This is complemented with the use of density functional theory (DFT) calculation of structures that have currently not been determined due to difficulties of obtained crystals of sufficient quality for X-ray determination. Additionally, DFT calculations were conducted for

Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years

• Asha Budakoti,
• Pradip Kumar Mondal,
• Prachi Verma and
• Jagadish Khamrai

Beilstein J. Org. Chem. 2021, 17, 932–963, doi:10.3762/bjoc.17.77

• and co-workers explained the formation of all-cis-2,4,6-trisubstituted THPs with the help of density functional theory (DFT) and stated that in the presence of an external nucleophile, the stabilization of the carbocation intermediate is favored through hyperconjugation [28]. The vacant p-orbital of

Synthesis, structural characterization, and optical properties of benzo[f]naphtho[2,3-b]phosphoindoles

• Mio Matsumura,
• Takahiro Teramoto,
• Masato Kawakubo,
• Masatoshi Kawahata,
• Yuki Murata,
• Kentaro Yamaguchi,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2021, 17, 671–677, doi:10.3762/bjoc.17.56

• ]. Unfortunately, the electrochemistry of some compounds could not be determined under the conditions available to us. Therefore, computational investigations are particularly useful for understanding the trends of the electrochemical and photophysical properties of molecular materials. Density functional theory

Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

• Vladislav A. Budevich,
• Sergei V. Voitekhovich,
• Alexander V. Zuraev,
• Vadim E. Matulis,
• Vitaly E. Matulis,
• Alexander S. Lyakhov,
• Ludmila S. Ivashkevich and
• Oleg A. Ivashkevich

Beilstein J. Org. Chem. 2021, 17, 385–395, doi:10.3762/bjoc.17.34

• structures are known [17][28]. Thus, the information on tetrazole-5-aminides is very limited and fragmentary. In the present work, we try to fill this gap by carrying out experimental (synthesis, X-ray, UV–vis) and theoretical density functional theory (DFT) studies of some selected 1,3-dialkyltetrazolium-5

• –vis spectra and charge transfer were carried out within density functional theory for ground states and time-dependent density functional theory (TD-DFT) for excited states using the τ-dependent hybrid tHCTHhyb functional [37] with the 6-311+G(2d,p) basis set [38]. The chosen functional allows to

Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic dienes

• Savva A. Ponomarev,
• Roman V. Larkovich,
• Alexander S. Aldoshin,
• Andrey A. Tabolin,
• Sema L. Ioffe,
• Jonathan Groß,
• Till Opatz and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2021, 17, 283–292, doi:10.3762/bjoc.17.27

• of CPD with the model nitrostyrene 1h was simulated in silico to predict the reaction pathway, the reaction rate constants, and the activation enthalpies. Density functional theory calculations were conducted for the reactants, products, and transition states using the B3LYP [64][65][66] and M062X

Exploring the possibility of using fluorine-involved non-conjugated electron-withdrawing groups for thermally activated delayed fluorescence emitters by TD-DFT calculation

• Dongyang Chen and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 210–223, doi:10.3762/bjoc.17.21

• -dependent density functional theory calculations indicate that when only two ortho-disposed carbazole donors are used (Type I molecules), the lowest-lying triplet state possesses locally excited (LE) character while the lowest-lying singlet state possesses charge-transfer character. When five carbazole

• states, followed by rISC [22]. This situation typically occurs when there are multiple donors about a single acceptor as exists in the molecules 5CzBN and 5CzTRZ. For 5CzBN, time-dependent density functional theory (TD-DFT) calculation revealed the existence of three intermediate triplet states [22]. The

• [28][29]. Results and Discussion We employed density functional theory (DFT) and TD-DFT calculations to predict the photophysical properties of these emitters in order to assess their potential as TADF emitters for OLEDs. All ground-state calculations were performed using PBE0/6-31G(d,p) in the gas

Pentannulation of N-heterocycles by a tandem gold-catalyzed [3,3]-rearrangement/Nazarov reaction of propargyl ester derivatives: a computational study on the crucial role of the nitrogen atom

• Giovanna Zanella,
• Martina Petrović,
• Dina Scarpi,
• Ernesto G. Occhiato and
• Enrique Gómez-Bengoa

Beilstein J. Org. Chem. 2020, 16, 3059–3068, doi:10.3762/bjoc.16.255

• studied computationally (Figure 2). To this end, a model substrate bearing p-toluensulfonyl as the protecting group on the nitrogen atom was chosen owing to the compatibility with such a process [16]. The structures were located using the B3LYP density functional theory method as implemented in the

UV resonance Raman spectroscopy of the supramolecular ligand guanidiniocarbonyl indole (GCI) with 244 nm laser excitation

• Tim Holtum,
• Vikas Kumar,
• Daniel Sebena,
• Jens Voskuhl and
• Sebastian Schlücker

Beilstein J. Org. Chem. 2020, 16, 2911–2919, doi:10.3762/bjoc.16.240

• the results from density functional theory (DFT) calculations. Keywords: GCI; GCP; guanidiniocarbonyl indole; guanidiniocarbonyl pyrrole; UVRR; Raman spectroscopy; resonance Raman; Introduction Supramolecular ligands are capable to selectively bind to peptides and proteins via reversible non

• the results from density functional theory (DFT) calculations. The assignment of the peaks detectable in the experimental UVRR spectrum is mainly based on the experimental wavenumber position (peak position). Only normal modes with non-vanishing Raman activities were considered. One cannot expect an

Fluorine effect in nucleophilic fluorination at C4 of 1,6-anhydro-2,3-dideoxy-2,3-difluoro-β-D-hexopyranose

• Danny Lainé,
• Vincent Denavit,
• Olivier Lessard,
• Laurie Carrier,
• Charles-Émile Fecteau,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2020, 16, 2880–2887, doi:10.3762/bjoc.16.237

• density functional theory (DFT) calculations). Finally, we wish to report the preparation of novel multi-vicinal fluorinated alditol analogues using a simple reduction protocol. Results and Discussion We initially supposed that DAST, a commonly used reagent to install fluorine atoms on the carbohydrate

Synthesis of purines and adenines containing the hexafluoroisopropyl group

• Viacheslav Petrov,
• Rebecca J. Dooley,
• Alexander A. Marchione,
• Elizabeth L. Diaz,
• Brittany S. Clem and
• William Marshall

Beilstein J. Org. Chem. 2020, 16, 2739–2748, doi:10.3762/bjoc.16.224

• that with the CF3 moieties nearer the five-membered ring of the azabenzimidazole unit, and the rotamer of higher energy was that with the CF3 moieties near the six-membered ring (see Figure 4). Density functional theory calculations predict an enthalpy difference of 0.48 kcal⋅mol−1 between the two

• supplementary publication nos. CCDC #1998565−1998569. Computational chemistry Computational optimization of 8a and 8b structures was performed with Gaussian 9 software. Density functional theory at the B3LYP level, with a 6-311g++ basis set (Co phase) was employed. Reaction of purine (2) and 1 A mixture of 1.2

Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• size distribution was measured from the desorption branch using the nonlocal density functional theory (NLDFT) model assuming a cylindrical pore structure. The average pore size was determined by the Dubinin–Radushkevich (DR) plot of the N2 desorption isotherm. The relative microporosity percentage is

Synthesis of 4-substituted azopyridine-functionalized Ni(II)-porphyrins as molecular spin switches

• Jannis Ludwig,
• Tobias Moje,
• Fynn Röhricht and
• Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2589–2597, doi:10.3762/bjoc.16.210

• is always in a high paramagnetic state (>80%) and showed only minor switching efficiency after irradiation (4%). This is attributed to intramolecular coordination of the trans state (Supporting Information File 1, Figure S17). Application of density functional theory (DFT) at the B3LYP/def2TZVP//PBE

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• diffraction. Therefore, the optimized geometry of the 1:1 complex of TBTQ-(OG)6 C60 in water was simulated by density functional theory (DFT) calculations at the B3LYP/6-31G(d) level of theory, which was completed with the aid of Molclus, MOPAC, and ORCA 4.1.0 programs [54][55][56]. As shown in Figure 6, C60

Conformational preferences of fluorine-containing agrochemicals and their implications for lipophilicity prediction

• Daniela Rodrigues Silva,
• Joyce K. Daré and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2020, 16, 2469–2476, doi:10.3762/bjoc.16.200

• high degree of freedom in the chemical structure of penoxsulam (I), the conformational analysis started with a Monte Carlo conformational search at the ωB97X-D/6-31G(d,p) [16][17] level of the density functional theory (DFT). The global energy minimum conformation was then re-optimized in a higher

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

• Anka Utama Putra,
• Deniz Çakmaz,
• Nurgül Seferoğlu,
• Alberto Barsella and
• Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

• series of new styryl-based organic chromophores containing a free amino group and the corresponding Schiff base derivatives. The photophysical, pH sensitivity, NLO properties, and thermal stabilities of all synthesized dyes were investigated. Density Functional Theory (DFT) calculations were also

• were calculated by Density Functional Theory at the B3LYP/6-31+G(d,p) level of theory in the gas phase [64][65]. This method was also applied to study the nonlinear optic (NLO) properties of the dyes in their ground states. The theoretical absorption spectra in different solvents were calculated using

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• thermoelectric properties in addition to the onigiri-type core-shell assemblies have been reported for sumanene and its derivatives. More interestingly, its application in the absorption of small molecules such as NH3, CO2, CO, and H2 using density functional theory (DFT) calculations has also been revealed [25

• /mol) transformation of 12 (syn) to 17, calculated by density functional theory (DFT) calculations. On the other hand, in 2008, Higashibayashi et al. reported the synthesis of first chiral C3-symmetric trimethylsumanene 28 starting from enantiopure norbornadiene (10) by employing a rational synthetic

• an LED lamp at ca. 365 nm for 1 min in 2-methyltetrahydrofuran (mTHF) at 77 K gave 60 (Scheme 13) [45]. It was noticed from both experimental as well as theoretical studies that the ground state of the prepared carbene 60 is a triplet which was confirmed by ESR as well as density functional theory

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

• (sp3)–H fluorination mechanistic studies: In order to unearth a greater understanding of their previously-reported photosensitized C(sp3)–H fluorination, Tan, Lu, Soo and co-workers employed a nanosecond-scale transient absorption (TA) spectroscopy and time-dependent density functional theory (TDDFT

Muyocopronones A and B: azaphilones from the endophytic fungus Muyocopron laterale

• Ken-ichi Nakashima,
• Junko Tomida,
• Tomoe Tsuboi,
• Yoshiaki Kawamura and
• Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 2100–2107, doi:10.3762/bjoc.16.177

• ) [25]. After conformational analysis, geometry optimization was performed for two possible stereoisomers with the (7S,10R,11R)- and (7S,10S,11S)-configurations using density functional theory (DFT) at the CAM-B3LYP/6-311+G(d,p) level of theory. In addition, the ECD spectra of the DFT-optimized

Isolation and structure determination of a tetrameric sulfonyl dilithio methandiide in solution based on crystal structure analysis and ⁶Li/¹³C NMR spectroscopic data

• Jürgen Vollhardt,
• Hans Jörg Lindner and
• Hans-Joachim Gais

Beilstein J. Org. Chem. 2020, 16, 2057–2063, doi:10.3762/bjoc.16.172

• negative hyperconjugation. Density functional theory and natural bond order calculations of dilithio methandiides of type II [32][43] suggest that the two lone pairs at the dianionic carbon atom of (2a)4·(THF)6 and (2a)6·Li2O·(THF)6 are perhaps located in an sp2 hybridized orbital and p orbital. However

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• advantageous: being a one-pot reaction with metal-free reagent, having shorter reaction times, good yields and a very simple purification method. Moreover, using the density functional theory (DFT) method at the M06-2X/6-31+G(d,p) level of theory the mechanism of the cycloaddition reactions has been elucidated

• isocyanate; computational modeling; cyclic carbonates; density functional theory; oxazolidinone; Introduction Oxazolidinones (1), five-membered heterocyclic rings containing an ester group adjacent to a nitrogen atom, are important compounds in synthetic and pharmaceutical chemistry because of their

Rearrangement of o-(pivaloylaminomethyl)benzaldehydes: an experimental and computational study

• Csilla Hargitai,
• Györgyi Koványi-Lax,
• Tamás Nagy,
• Péter Ábrányi-Balogh,
• András Dancsó,
• Gábor Tóth,
• Judit Halász,
• Angéla Pandur,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2020, 16, 1636–1648, doi:10.3762/bjoc.16.136

• reaction described in Scheme 1 to further o-(pivaloylaminomethyl)benzaldehydes and to support the results by density functional theory (DFT) calculations, single-crystal X-ray measurements and comprehensive NMR studies. Results and Discussion Acid-catalyzed transformations of compounds 1a–d First we kept