Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• provided the desired carboamination product 164. By using methyl cinnamate derivatives, the reactions were highly diastereoselective for the formation of 1,2-anti carboamination products. Notably, the Ritter reaction was found to be the origin of diastereoselectivity on the basis of a density functional

• theory (DFT) mechanistic study. The authors proposed a radical-polar crossover mechanism. First, a SET from Fe(II) to the alkyl diacyl peroxide generates the alkyl acyloxy radical which decarboxylates to afford the alkyl radical 165. Addition of the radical across the alkene affords the benzylic radical

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• density functional theory calculations [46]. Recently, Shi, Lin and co-workers reported the atroposelective synthesis of axially chiral biaryls by Pd(II)-catalyzed free amine-directed atroposelective C–H olefination using chiral spirophosphoric acid CPA 5 as an efficient ligand and Ag2CO3 as the oxidant

• the desired axially chiral pyrazole derivatives 56 in good yields (up to 99%) with excellent enantioselectivities (up to 98% ee, Scheme 19). Density functional theory calculations revealed that the chiral phosphoric acid acts as a proton-transfer shuttle to assist proton transfer from the OH group of

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• enantioselectivity (47–98% ee). The observed results were rationalized with density functional theory calculations (Table 8) [42]. 1.3 Reactions catalyzed by chiral amines He and co-workers developed heterogeneous synergistic catalysis using chiral amines SBA-15 (cat. 44), which promote aza-Michael–Henry cascade

Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 2450–2461, doi:10.3762/bjoc.17.162

• their HOMO/LUMO energy levels were estimated by cyclic voltammetry measurements. Besides, density functional theory calculations were carried out for further exploration of their electronic properties. Keywords: catalysis; cross-coupling; cyclization; fluorescence; palladium; Introduction π-Conjugated

• a PGSTAT30 Autolab potentiostat. Theoretical calculations The theoretical studies were realized in vacuum with the Gaussian 09 program [70]. The geometry of the equilibrium conformer at the ground state was first found at AM1 level. Then, further optimization through density functional theory (DFT

Nomimicins B–D, new tetronate-class polyketides from a marine-derived actinomycete of the genus Actinomadura

• Zhiwei Zhang,
• Tao Zhou,
• Taehui Yang,
• Keisuke Fukaya,
• Enjuro Harunari,
• Shun Saito,
• Katsuhisa Yamada,
• Chiaki Imada,
• Daisuke Urabe and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2194–2202, doi:10.3762/bjoc.17.141

• functional theory (DFT) calculation of the ECD spectrum for 4, for which the absolute configuration was established by the modified Mosher’s method in our previous work [15]. Since the acyltetronic acid exists as a mixture of keto–enol tautomers, the calculation was carried out using the four possible

• (Table S1, Supporting Information File 1) and 3JHH coupling constants [15]. The absolute configuration of 1 was deduced to be the same as 4 in consideration of the overall similarity of the electronic circular dichroism (ECD) spectra of 1 and 4 (Figure 4). This proposition was evidenced by the density

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