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

• 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

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

• 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

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

• 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

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

• 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

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• experimentally observed stereoselectivity. Keywords: azomethine ylides; cycloaddition; cyclopropenes; DFT calculations; spiro heterocycles; Introduction Spiro compounds (molecules containing at least two rings with only one common atom) are an important class of both synthetic and naturally occurring

• ourselves exclusively to carrying out laboratory experiments. We turned to DFT calculations (M11 density functional theory) [42][43][44][45][46] to interpret the experimental results. At the beginning of the computational study, we evaluated the relative stability of prototropic tautomers which are formed

• diastereoselective approach for the synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane through cycloaddition reactions of a stable azomethine ylide – protonated Ruhemann's purple to cyclopropenes. The cycloaddition reaction is compatible with a broad scope of cyclopropenes. DFT calculations

Structural basis for endoperoxide-forming oxygenases

• Takahiro Mori and
• Ikuro Abe

Beilstein J. Org. Chem. 2022, 18, 707–721, doi:10.3762/bjoc.18.71

• molecular dynamics analyses, as well as DFT calculations of the FtmOx1 reaction, suggested a modified mechanism [72][73][74]. In this mechanism, the tyrosyl radical at Tyr224 is generated by the Fe(IV)=O species, which abstracts a hydrogen atom at C21 to form an endoperoxide ring through the reaction with

Syntheses of novel pyridine-based low-molecular-weight luminogens possessing aggregation-induced emission enhancement (AIEE) properties

• Masayori Hagimori,
• Tatsusada Yoshida,
• Yasuhisa Nishimura,
• Yukiko Ogawa and
• Keitaro Tanaka

Beilstein J. Org. Chem. 2022, 18, 580–587, doi:10.3762/bjoc.18.60

• -induced emission enhancement (AIEE) properties in aqueous media. Compounds 4a and 4e, bearing electron-withdrawing groups (Br and CF3, respectively) showed 7.0 and 15 times fluorescence enhancement. Time-dependent density functional theory (TD-DFT) calculations were performed to gain better insight into

• in AIEE. To compare the electronic natures of the compounds with and without AIEE, we performed TD-DFT calculations on each monomer of 3a, 4a, and 4e. The graphical representations of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) for the ground-state

• (Br and CF3, respectively) exhibited a large fluorescence enhancement. A comparison of the calculated and observed Exmax using TD-DFT calculations revealed the basic features of compounds 4. Therefore, we envision N-methyl-4-((pyridin-2-yl)amino)-substituted maleimides based on an A–D–A system as

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• for the non-interlocked mixture, see Figure 15). DFT calculations showed that the reaction takes place by cooperative action of the Li phosphate macrocycle and the amine thread, enabled by the mechanical bond. The Li phosphate acts as a Lewis acid to activate the malonic acid diethyl ester, which is

Iridium-catalyzed hydroacylation reactions of C1-substituted oxabenzonorbornadienes with salicylaldehyde: an experimental and computational study

• Angel Ho,
• Austin Pounder,
• Krish Valluru,
• Leanne D. Chen and
• William Tam

Beilstein J. Org. Chem. 2022, 18, 251–261, doi:10.3762/bjoc.18.30

• electron-withdrawing groups inactivates the iridium catalyst, perhaps by chelation with the carbonyl and the bridging oxygen atom. Computational Computational details All density functional theory (DFT) calculations in this study were carried out with the Gaussian 16, C.01 suite of programs [68]. Geometry

• calculated from the optimized structures by single-point calculations by adding thermochemical corrections to the electronic energy. Optimized structures are illustrated using CYLview [73]. In order to further understand the iridium-catalyzed hydroacylation reaction, we carried out DFT calculations on the

• diminished product yields. Using DFT calculations, we investigated the [Ir(COD)OH]2-catalyzed hydroacylation reactions of C1-substituted OBDs. From these results, we found the reductive elimination step is the rate-determining step and the origin of regioselectivity for the catalytic cycle. Moreover, we

The enzyme mechanism of patchoulol synthase

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2

• contradictory. For this reason, we have reinvestigated the enzyme mechanism of PTS in isotopic labelling experiments through methods recently developed in our laboratory that make use of 13C and 2H-substituted terpene precursors, and by DFT calculations. The general strategy in these experiments is to use

• experiments and the DFT calculations were not only carried out in a way to gain support for one mechanism, but also to disprove some of the earlier reports in order to resolve the contradictions in the literature. Results and Discussion Absolute configurations of patchoulol and pogostol In order to

• , but this deuterium loss for 5 is best explained by the terminal deprotonation step from C6. Investigations on patchoulol biosynthesis by DFT calculations The biosynthesis of 3 was also investigated by DFT calculations (Figure 3). For the mechanism proposed by Croteau et al. (Scheme 1) [9], the

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• in i + 4-position of the linear axin CBD sequence aAxWt were substituted by tryptophan and lysine, respectively, to have a higher analogy to the lysine modified SMC stapled peptides. Following the indications of DFT calculations, stapled peptide P5 was synthesised by modification of lysine in the i

• for support in the synthetic work. Funding The project was supported in part by a Bielefeld University Ph.D. fellowship to H.G. and by Deutsche Forschungsgemeinschaft (SE609/16-1). The DFT calculations were carried out using hardware and software resources of the Supercomputing and Networking Center

DABCO-promoted photocatalytic C–H functionalization of aldehydes

• Bruno Maia da Silva Santos,
• Mariana dos Santos Dupim,
• Cauê Paula de Souza,
• Thiago Messias Cardozo and
• Fernanda Gadini Finelli

Beilstein J. Org. Chem. 2021, 17, 2959–2967, doi:10.3762/bjoc.17.205

• , in a similar fashion of previous reports [31][32]. However, addition of bromide from external sources led to diminished yields (Supporting Information File 1, Table S6). Also, DFT calculations demonstrated that a HAT reaction between bromine radical and isovaleraldehyde is a barrierless reaction

• results do not support this is the operating mechanism and further investigations are underway to determine a plausible path for the reaction in the absence of bicyclic amine catalysts (see Supporting Information File 1, chapter 8 for details). The HAT step with 1 was investigated by DFT calculations at

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• DICzTRZ were determined by a combination of NMR spectroscopy, mass spectrometry, and IR spectroscopy. Theoretical calculations Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations in the gas phase at the PBE0/6-31G(d,p) level reveal the potential of DICzTRZ as a TADF material. The

• , respectively, while the S1 level for DICzTRZ is more stabilized at 2.80 eV vs 2.94 eV for ICzTRZ). We can clearly observe that the phosphorescence spectrum presents a well-defined structure, typical for transitions coming from a local excited (LE) type state on the diindolocarbazole. TDA-DFT calculations in

• EML. Thus, vacuum deposition of this family of TADF emitters is clearly superior to solution processing. Conclusion Building upon our previously reported emitter, ICzTRZ, here we presented a dual emitter strategy consisting of two ICzTRZ moieties covalently linked together in the form of DICzTRZ. DFT

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• , C. tropicalis, and C. glabrata standard strains. A deep conformational survey was monitored using DFT calculations with the aim to explain the importance of the final conformation in the biological experimental results. Keywords: antituberculosis; bidentate ligands; DFT; nickel; palladium

• results of its corresponding nickel(II) [18] and palladium(II) [19][20] complexes with the analogous tests obtained in the case of having a benzylic substituent at the same position. Also, DFT calculations are run in order to study the conformational analysis of the synthetized complexes. Results and

• 62.50–125 μg/mL (Table 2) when compared to reference drugs. the L3-Ni complex has the highest activity against Candida glabrata. DFT calculations of complexes The survey of relationship between structure of the complex and activity (SAR) moved us to design DFT calculations. The difference of the

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

• provide easy access to the privileged NOBIN (2-amino-2’-hydroxy-1,1’-binaphthyl) structures 41. The additional insights into the origins of enantiocontrol were described by DFT calculations. Owing to the presence of axially chiral indole-based biaryl scaffolds such as naphthylindoles and phenylindoles in

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

• Viera Poláčková,
• Dominika Krištofíková,
• Boglárka Némethová,
• Renata Górová,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

• influence on the catalytic reactions. Under ball-milling conditions, the Michael adducts were obtained in good yields but with slightly lower enantiomeric purities than in solution. DFT calculations elucidated its mode of action and confirmed a dual activation mode, which combines enamine activation of

• have evaluated the suitability of these catalysts under solvent-free conditions. With the help of DFT calculations, we elucidated the mode of action of these catalysts. Results and Discussion Synthesis of catalysts We have started the synthesis of the catalysts from Boc-protected (S)-prolinol (1), from

• 8f in 76 and 79% yield with comparable diastereoselectivity and enantioselectivity (Table 4, entries 8 and 9). DFT calculations of catalyst structure and reaction stereo-course To understand the catalyst operation, we have conducted DFT calculations of its structure and reaction course. All

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

• and their optical and electrochemical properties investigation by the use of UV–vis and emission spectroscopy, CV measurements as well as DFT calculations. Results and Discussion Synthesis. At the beginning of this study, we synthesized 2,4-dibromo-9-chloro-5,6,7,8-tetrahydroacridine (2) by refluxing

• further study the electronic properties, DFT calculations were carried out on the fully ground state at the restricted B3LYPlevel with 6-31G(d) basis set using dichloromethane as a continuum solvent model. The optimized chemical structures of 4a–d are given in Figure 7 with selected geometrical parameters

• 4f. Calculated energy levels for compounds 4a–d and their spatial distribution of the HOMO–LUMO frontier molecular orbitals from DFT calculations. Visualization of MEP for compounds 4a–d calculated by B3LYP method with 6-31G(d) basis set. Cyclic voltammogram for 4c in 0.1 M (n-Bu)4NBF4/acetonitrile

Synthesis of 5-arylacetylenyl-1,2,4-oxadiazoles and their transformations under superelectrophilic activation conditions

• Andrey I. Puzanov,
• Dmitry S. Ryabukhin,
• Anna S. Zalivatskaya,
• Dmitriy N. Zakusilo,
• Darya S. Mikson,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2021, 17, 2417–2424, doi:10.3762/bjoc.17.158

• bond of these oxadiazoles quantitatively resulted in E/Z-vinyl triflates. The reactions of the cationic intermediates have been studied by DFT calculations and the reaction mechanisms are discussed. Keywords: acetylene-oxadiazoles; Friedel–Crafts reaction; hydroarylation; superelectrophilic activation

• expect the formation of similar dications at the protonation of acetylenyloxadiazoles 3 in Brønsted superacids (see Table 1). Table 1 contains data on DFT calculations of cations Aa–d (N-protonated forms) and Ba–d (N,C-diprotonated forms) derived at the protonation of oxadiazoles 3a–d. Charge

• positive charge (0.40–0.47 e) and gives a big contribution into LUMO (16.7–30%), pointing out that this carbon is a reactive electrophilic center by charge and orbital factors. Thus, according our previous data on reactions of 5-styryl-1,2,4-oxadiazoles 1 [24] and results of the DFT calculations for

Halides as versatile anions in asymmetric anion-binding organocatalysis

• Lukas Schifferer,
• Martin Stinglhamer,
• Kirandeep Kaur and
• Olga García Macheño

Beilstein J. Org. Chem. 2021, 17, 2270–2286, doi:10.3762/bjoc.17.145

• example highlighting the importance of sidechain catalyst design was given by Jacobsen et al. in the tail-to-head cyclization of neryl chloride and derivatives 59 (Scheme 13) [17]. Mechanistic studies and DFT calculations revealed that an extended π-system in the sidechain of the bidentate urea catalyst

Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs

• Jongwoo Son

Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122

• . Additionally, difluorination was observed with negligible amounts because the monofluorinated product is rendered more electronically deficient by the first fluorine atom. Based on an analysis by DFT calculations, the postulated reaction pathway of manganese-catalyzed C–H fluorination is described in Figure 1

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

• activity of differently substituted triarylphosphines in the oxa-Michael addition of alcohols to electron-deficient olefins was investigated. In general, the activity increases with increasing methoxy-substitution in the order TPP < MMTPP < TMTPP. The activity order was rationalized based on DFT

• calculations by an increasing stationary concentration of the primary reaction product, the corresponding β-phosphonium α-carbanionic zwitterion, when using arylphosphines with more electron-donating substituents. Besides the catalyst, the second decisive factor for the speed of the reaction is the acidity of

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• investigated by means of DFT calculations using the reaction between enaminone 6a and phenyl azide. TS1 and TS2 have been proposed as two transition states, which then converted to IN1 and IN2 as two possible isomers. The stable final products were achieved via a cascade reaction including the elimination of

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

Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Tsutomu Kimura,
• Koto Sekiguchi,
• Akane Ando and
• Aki Imafuji

Beilstein J. Org. Chem. 2021, 17, 1352–1359, doi:10.3762/bjoc.17.94

• magnesium alkylidene carbenoids was studied by using 13C-labeled sulfoxides and by using DFT calculations. Keywords: alkyne; 1-chlorovinyl p-tolyl sulfoxide; DFT calculation; Fritsch–Buttenberg–Wiechell rearrangement; magnesium alkylidene carbenoid; Introduction Alkynes are important compounds in organic

• rearrangement of magnesium alkylidene carbenoids 3 by using 13C-labeled sulfoxides and by using DFT calculations is also described. Results and Discussion Synthesis of 1-heteroatom-substituted vinyl p-tolyl sulfoxides As magnesium alkylidene carbenoid precursors, a series of 1-heteroatom-substituted vinyl p

• (Scheme 3a). The 2,2-unsymmetrically substituted sulfoxides 2d–g were obtained as mixtures of geometric isomers that were separated by column chromatography on silica gel. FBW rearrangement of magnesium alkylidene carbenoids Based on the results of DFT calculations, the degree of the vinylidene character

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

• need of crystallization, using DFT calculations with a high degree of accuracy. Keywords: conformational analysis; crystal engineering; halogenation; macrocycles; porphyrins; Introduction Crystal engineering using porphyrins as a scaffolding unit has been a topic of increasing interest over the past

• 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

• structures, the features are generally similar to each other. DFT calculations and NSD analysis The limited availability of meso-halogenic porphyrin crystal structures in the CSD makes it difficult to study a complete series. While we can develop certain trends based on the current data sets, the gaps