Synthesis and fluorescent properties of N(9)-alkylated 2-amino-6-triazolylpurines and 7-deazapurines

• Andrejs Šišuļins,
• Jonas Bucevičius,
• Yu-Ting Tseng,
• Irina Novosjolova,
• Kaspars Traskovskis,
• Ērika Bizdēna,
• Huan-Tsung Chang,
• Sigitas Tumkevičius and
• Māris Turks

Beilstein J. Org. Chem. 2019, 15, 474–489, doi:10.3762/bjoc.15.41

• heterocycles, which were additionally extended by triazole moieties, the compounds with electron-donating groups showed intramolecular charge transfer character (ICT/TICT) of the excited states which was proved by solvatochromic dynamics and supported by DFT calculations. In the 7-deazapurine series this led

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

• Guillaume Ernouf,
• Jean-Louis Brayer,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

• corresponding diastereomeric phosphine oxides 7a/7’a, even upon prolonged heating (toluene, 110 °C), and underwent slow decomposition instead (Scheme 5). This observation was in agreement with DFT calculations which indicated that the rearrangement of cyclopropenylmethyl phosphinite I, although

Catalysis of linear alkene metathesis by Grubbs-type ruthenium alkylidene complexes containing hemilabile α,α-diphenyl-(monosubstituted-pyridin-2-yl)methanolato ligands

• Tegene T. Tole,
• Johan H. L. Jordaan and
• Hermanus C. M. Vosloo

Beilstein J. Org. Chem. 2019, 15, 194–209, doi:10.3762/bjoc.15.19

• application of these systems at higher temperatures. Overall precatalyst 7 performed the best at all temperatures (except at 80 °C). In an attempt to understand the significance of these results, DFT calculations were performed on the precatalysts. Precatalyst 6 showed the lowest activity of all precatalysts

Computational characterization of enzyme-bound thiamin diphosphate reveals a surprisingly stable tricyclic state: implications for catalysis

• Ferran Planas,
• Michael J. McLeish and
• Fahmi Himo

Beilstein J. Org. Chem. 2019, 15, 145–159, doi:10.3762/bjoc.15.15

• the enzyme [19][20]. Thirty years later, density functional theory (DFT) calculations showed that the 4′-amino moiety of the cofactor can either accept or donate a proton in the reactions, depending on the protonation state of N1′ [21]. Orbital analysis of the IP/YIH+ reaction showed that full

• seemed logical to take a closer look at the relative energies of the various states and how those energies may be affected by the binding of different ligands. Toward that end, we have used DFT calculations to explore the energetics of the various states of enzyme-bound ThDP using benzoylformate

Regioselective addition of Grignard reagents to N-acylpyrazinium salts: synthesis of substituted 1,2-dihydropyrazines and Δ⁵-2-oxopiperazines

• Valentine R. St. Hilaire,
• William E. Hopkins,
• Yenteeo S. Miller,
• Srinivasa R. Dandepally and
• Alfred L. Williams

Beilstein J. Org. Chem. 2019, 15, 72–78, doi:10.3762/bjoc.15.8

• Grignard reagent to add regioselectively to give 1,2-dihydropyrazine 3a. DFT calculations support the observations that the isolated regioisomer we obtained was the result of a thermodynamically favored 1,2-addition over a 1,6-addition [9]. It has also been shown that TMS-ketene acetals add selectively to

The activity of indenylidene derivatives in olefin metathesis catalysts

• Maria Voccia,
• Steven P. Nolan,
• Luigi Cavallo and
• Albert Poater

Beilstein J. Org. Chem. 2018, 14, 2956–2963, doi:10.3762/bjoc.14.275

• [29][30][31]. We are interested in evaluating, by density functional theory (DFT) calculations, the difference in the activation step between complexes 1–6 in Scheme 1, whose reactivity and properties have been reported already (for 1 and 2) [24][32][33]. Predictive catalysis will be used here to

• lengths are given in Å). Catalysts studied by DFT calculations. Precatalyst initiation in olefin metathesis (L = NHC ligand). Precatalyst initiation reaction pathway for catalysts 1–6 (M06/TZVPsdd//BP86/SVPsdd; Gibbs free energies in kcal/mol). Structural analysis for species I–III for catalysts 1–6 (in

1,8-Bis(dimethylamino)naphthyl-2-ketimines: Inside vs outside protonation

• A. S. Antonov,
• A. F. Pozharskii,
• P. M. Tolstoy,
• A. Filarowski and
• O. V. Khoroshilova

Beilstein J. Org. Chem. 2018, 14, 2940–2948, doi:10.3762/bjoc.14.273

• -arylketimines of 1,8-bis(dimethylamonio)naphthalene with a different number of methoxy groups in an aromatic substituent were investigated in solution by NMR (acetone, DMSO, MeCN), in solid state by X-ray analysis and in the gas phase by DFT calculations. Both mono- and diprotonated species were considered. It

Generation of 1,2-oxathiolium ions from (arysulfonyl)- and (arylsulfinyl)allenes in Brønsted acids. NMR and DFT study of these cations and their reactions

• Stanislav V. Lozovskiy,
• Alexander Yu. Ivanov,
• Olesya V. Khoroshilova and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2018, 14, 2897–2906, doi:10.3762/bjoc.14.268

• , D2SO4), (arysulfonyl)allenes (ArSO2–CR1=C=CR2R3) and (arylsulfinyl)allenes (ArSO–CR1=C=CR2R3) undergo cyclization into the corresponding stable 1,2-oxathiolium ions, which were studied by means of NMR and DFT calculations. Quenching of solutions of these cations with low nucleophilic media, aqueous HCl

• allenes 2. The main goals of this work were the investigation of reactions of sulfur-containing allenes 1 and 2 under electrophilic activation with Brønsted or Lewis (super)acids, and the study on cationic intermediates of these reactions by means of NMR and DFT calculations. Results and Discussion First

• such broad series of cyclic sulfur containing cations Aa,b and Ba–h. Allenes 2i,j did not react with acids at room temperature, however, they react with TfOH at higher temperature (see below). To estimate the charge distribution in species Aa, Ba we carried out DFT calculations (Table 2). The

Unprecedented nucleophile-promoted 1,7-S or Se shift reactions under Pummerer reaction conditions of 4-alkenyl-3-sulfinylmethylpyrroles

• Takashi Go,
• Akane Morimatsu,
• Hiroaki Wasada,
• Genzoh Tanabe,
• Osamu Muraoka,
• Yoshiharu Sawada and
• Mitsuhiro Yoshimatsu

Beilstein J. Org. Chem. 2018, 14, 2722–2729, doi:10.3762/bjoc.14.250

• calculations (Table 2) [36]. Whether the reactions lead to the formation of pyrroloazepines or diols clearly depends on the substituents in the alkenyl group. We performed DFT calculations for the reaction pathways starting from the key intermediate 14 bearing methyl and phenyl groups. The DFT-calculated ΔG

• Information For crystallographic data see also CCDC 1824587 and 1824588. Supporting Information File 226: Schemes S1 and S2 on the syntheses of compounds 1, 2, and 3a–g; the NMR study for the structure determinations, further DFT calculations, the ORTEP drawing of both sulfone of 5a, 11d and the 1H and 13C

Calixazulenes: azulene-based calixarene analogues – an overview and recent supramolecular complexation studies

• Paris E. Georghiou,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Hidetaka Nishimura,
• Jaehyun Lee,
• Atsushi Wakamiya and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2018, 14, 2488–2494, doi:10.3762/bjoc.14.225

• ]azulene 3. To shed light on possible explanations for these findings, our attention was again directed to computational results derived from DFT calculations which are increasingly being commonly used in supramolecular chemistry. The ωB97xD functional [25] which combines the long range functional ωB97x

• constants. Conclusion Based upon the DFT calculations which we previously conducted in the solid-state study of 5 with C60, we postulated that due to the mechanochemical method of combining both components and the spherical nature of C60 that a possible interaction mode between host and guest could be as

• for the three different conformations of 5. Supporting Information Supporting Information File 355: Experimental determination of binding constants and DFT calculations. Supporting Information File 356: MOL files. Acknowledgements This project was supported by King Saud University, Deanship of

A challenging redox neutral Cp*Co(III)-catalysed alkylation of acetanilides with 3-buten-2-one: synthesis and key insights into the mechanism through DFT calculations

• Andrew Kenny,
• Alba Pisarello,
• Arron Bird,
• Paula G. Chirila,
• Alex Hamilton and
• Christopher J. Whiteoak

Beilstein J. Org. Chem. 2018, 14, 2366–2374, doi:10.3762/bjoc.14.212

• not affect the obtained yield (2p). In an effort to further understand the reaction mechanism involved in the C–H functionalisation of acetanilide substrates with 3-buten-2-one, we employed DFT calculations (Figure 1) using M06 level of theory which has been previously successfully applied for cobalt

• energy difference between the C–H activation and C–C bond formation steps makes identification of the rate limiting step difficult by DFT calculations alone, however, parallel kinetic isotope effect (KIE) experiments do suggest that the C–H activation step is not rate limiting (KIE = 1.3), which is not

• Supporting Information File 1. Computational details: All DFT calculations undertaken using the ORCA 3.03 computational software [32]. Optimisations were performed at the BP86-D3BJ/def2-TZVP level of theory [33][34][35][36][37][38][39] and final single point energies and solvation corrections calculated at

Determining the predominant tautomeric structure of iodine-based group-transfer reagents by ¹⁷O NMR spectroscopy

• Nico Santschi,
• Cody Ross Pitts,
• Benson J. Jelier and
• René Verel

Beilstein J. Org. Chem. 2018, 14, 2289–2294, doi:10.3762/bjoc.14.203

• at natural abundance with DFT calculations, we establish a convenient method to provide solution-phase structural insights for this class of ubiquitous reagents. In particular, we confirm that Shen’s revised, electrophilic SCF3-transfer reagent also adopts an "acyclic" thioperoxide tautomeric form in

• is predicted to be thermodynamically favored over the cyclic form 5a by more than 10 kcal/mol by DFT calculations [5]. However, this type of computational analysis is in general still not decisive. For example, while Togni reagent 4a is thermodynamically less favorable than its acyclic isomer 4b by

Hydroarylations by cobalt-catalyzed C–H activation

• Rajagopal Santhoshkumar and
• Chien-Hong Cheng

Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202

• yields with anti-selectivity. The alkene product originally should be syn-13, but it rearranged to anti-13 at the high reaction temperature likely catalyzed by the cobalt complex. Moreover, the found intermolecular KIE of 1.4 and density functional theory (DFT) calculations strongly suggest that the

• amines, and silyl alkynes in the presence of CoCp*(CO)I2 catalyst gave uncommon branched-selective products 16 in good yields with reasonable selectivity (Scheme 12) [56]. DFT calculations indicated that the regioselectivity of silyl alkynes was controlled by its steric effect in the protonolysis step

• , whereas the electronic nature of propargyl alcohols and amines played a key role in the selectivity control during the insertion. Moreover, the control experiments and DFT calculations show that HOPiv played a crucial role in both the C−H activation and the protonolysis step. In 2016, Yu and co-workers

Selective formation of a zwitterion adduct and bicarbonate salt in the efficient CO₂ fixation by N-benzyl cyclic guanidine under dry and wet conditions

• Yoshiaki Yoshida,
• Naoto Aoyagi and
• Takeshi Endo

Beilstein J. Org. Chem. 2018, 14, 2204–2211, doi:10.3762/bjoc.14.194

• adduct and bicarbonate salt between CO2 and N-benzyl cyclic guanidine 1. The structures of the zwitterionic adduct and bicarbonate salt were analyzed in detail and proved by elemental analysis, FTIR-ATR, solid-state NMR, TGA, and DFT calculations. In this report, the zwitterionic adduct of the monocyclic

Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

• Hendrik V. Schröder and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2018, 14, 2163–2185, doi:10.3762/bjoc.14.190

• , DFT calculations, and UV–vis spectroscopy confirmed five different redox states (TTF/NDI, TTF●+/NDI, TTF2+/NDI, TTF/NDI●−, TTF/NDI2−) and shows interesting optical properties in each of these redox states making this type of mechanically constrained donor–acceptor complex very interesting for

Calix[6]arene-based atropoisomeric pseudo[2]rotaxanes

• Carmine Gaeta,
• Carmen Talotta and
• Placido Neri

Beilstein J. Org. Chem. 2018, 14, 2112–2124, doi:10.3762/bjoc.14.186

• is the most populated in solution, consequently, the threading of this conformation, besides being faster, it is also favored by its abundance in solution. The greater thermodynamic stability of the 2+1cone atropoisomer over the 2+11,2,3-alt one, was confirmed by DFT calculations at the B3LYP/6-31G(d

• NMR studies of hexyloxycalix[6]arene 1, 2D COSY and HSQC spectra of atropoisomeric pseudorotaxanes, details of DFT calculations and atomic coordinates. Acknowledgements The authors acknowledge the Regione Campania (POR CAMPANIA FESR 2007/2013 O.O.2.1, CUP B46D14002660009) for the FT-ICR mass

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

• MOPAC 2016 program [61] with discard of repeated duplicates. Then unique conformers were combined with calix[4]arene core, and corresponding cations and complexes with ATP/ADP were optimized by DFT calculations. For DFT calculations Priroda 16 program [62] with build-in PBE functional on L2 basis level

• [63] was used. Then optimized structures were calculated using DFT calculations with CPCM model of solvation in water with Gaussian 09 program [47] with B3LYP functional on 6-311g basis level. Molecular structure of 8a (50% ellipsoids). The dashed line indicates the alternative position of the

• clarity) and optimized complex structure of 10a with ADP (c) and ATP (d) according to DFT calculations. UV spectra of EY (1), 10b–EY (2), and 10b–EY in the presence of 0.005 (3), 0.05 (4), 0.5 (5) and 2 (6) mM of ADP (a) or ATP (b). Concentration (EY) = 5 µM, concentration (10b) = 6 µM, concentration (MES

Synthesis and characterization of π–extended “earring” subporphyrins

• Haiyan Guan,
• Mingbo Zhou,
• Bangshao Yin,
• Ling Xu and
• Jianxin Song

Beilstein J. Org. Chem. 2018, 14, 1956–1960, doi:10.3762/bjoc.14.170

• Education Department (Grant No. 17B156). We thank Prof. Shubin Liu and Mr. Donghai Yu for their help in DFT calculations.

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• autocorrelation function were employed to judge the quality of the fits. For molecular modelling simulations, the initial structure of the ruthenium complex was obtained from previous DFT calculations using a previously reported methodology [82]. The geometries of the RAFTs and calixarene were built using DS

DFT calculations on the mechanism of copper-catalysed tandem arylation–cyclisation reactions of alkynes and diaryliodonium salts

• Tamás Károly Stenczel,
• Ádám Sinai,
• Zoltán Novák and
• András Stirling

Beilstein J. Org. Chem. 2018, 14, 1743–1749, doi:10.3762/bjoc.14.148

• copper(III)-catalysed carboarylation–ring closure reactions leading to the formation of functionalised heterocycles. We have performed DFT calculations along selected routes and compared their free energy profiles. The calculations considered two viable options for the underlying mechanism which differ

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• macromolecular shape in solution). DFT calculations (in solution), (VT) NMR and IR (KBr) spectroscopy supported these assignments. TEM analysis revealed the ability of the title compounds towards self-assembling into homogeneously packed spherical nano-aggregates. Conclusions: The (non)covalent synthesis and

• quantitative yields (Scheme 4) (Supporting Information File 1, pp. S6–S11; pp. S24–S39, Figures S25–S54). 3 Structural assignments Our research continued with a structural study, implemented by means of DFT calculations, solution (VT) NMR techniques, IR (KBr) spectroscopy and TEM analysis. 3.1 Assignments

• based on DFT calculations of G-0 and G-1 dendrons: optimal geometry and solvation effects First, we attempted to explain the generally difficult conditions encountered during synthesis (Schemes 2–4) based on DFT calculations [50][51][52][53][54][55][56] (Figure 2 and Table 2). As in the case of other

Cobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion

• Eric Detmar,
• Valentin Müller,
• Daniel Zell,
• Lutz Ackermann and
• Martin Breugst

Beilstein J. Org. Chem. 2018, 14, 1537–1545, doi:10.3762/bjoc.14.130

• ORCA 4 [65]. All DFT calculations were performed with Turbomole 7.1 [66][67] and the NCIPLOT code was employed for the visualization non-covalent interactions [48][49]. Experimental Details General remarks: Catalytic reactions were carried out in Schlenk flasks under nitrogen atmosphere using predried

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• PMMA thin-film. DFT calculations helped to ascribe the nature of the frontier molecular orbitals as being carbazole/phenoxy and phenylbenzimidazole for HOMO and LUMO, respectively. OLED devices were fabricated employing complexes 41–43 as emitting dopants with the following architecture ITO/HATCN (10

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• major isomer (Scheme 10). Compound 18 is a valuable intermediate for a variety of coupling reactions to yield 1,5-disubstituted imidazoles – structural motifs which are generally difficult to obtain – in a selective fashion. The proposed reaction mechanism based on DFT calculations starts with the

Stereoselective nucleophilic addition reactions to cyclic N-acyliminium ions using the indirect cation pool method: Elucidation of stereoselectivity by spectroscopic conformational analysis and DFT calculations

• Koichi Mitsudo,
• Junya Yamamoto,
• Tomoya Akagi,
• Atsuhiro Yamashita,
• Masahiro Haisa,
• Kazuki Yoshioka,
• Hiroki Mandai,
• Koji Ueoka,
• Christian Hempel,
• Jun-ichi Yoshida and
• Seiji Suga

Beilstein J. Org. Chem. 2018, 14, 1192–1202, doi:10.3762/bjoc.14.100

• reacted with several nucleophiles. These reactions afforded disubstituted piperidine derivatives with high diastereoselectivities and good to excellent yields. The conformations of the obtained N-acyliminium ions were studied by low temperature NMR analyses and DFT calculations and were found to be

• presents the diastereoselective synthesis of disubstituted piperidine derivatives by the indirect cation pool method and the elucidation of the stereoselectivity based on both NMR analyses of the cyclic N-acyliminium ions and DFT calculations. Results and Discussion N-Acyliminium ions obtained from N-Boc

• , respectively. These explanations are consistent with above mentioned conformational analyses results, and the hypothesis was in agreement with the experimental results (Figure 6). To obtain further insight in the conformation of the cyclic N-acyliminium ions, DFT calculations of C1–C6 were performed (Figure 7