Click chemistry towards thermally reversible photochromic 4,5-bisthiazolyl-1,2,3-triazoles

• Chenxia Zhang,
• Kaori Morinaka,
• Mahmut Kose,
• Takashi Ubukata and
• Yasushi Yokoyama

Beilstein J. Org. Chem. 2019, 15, 2161–2169, doi:10.3762/bjoc.15.213

• , and (2) changing the substituents on the phenyl rings at the peripheral of the molecule. Finally, we would like to discuss the solvent effects on the thermal back reactions of 1c, 2c, and 3c. As can be seen in Figure S13, the solvents are classified into two categories: (1) polar solvents (EtOH and

• Supporting Information File 1). The absorption spectral properties are summarized in Table 1 together with their predicted absorption maxima obtained by TD DFT calculations in vacuum [35]. Although 1o and 2o showed substantial coloration, 3o showed only a slight coloration at room temperature. The solvent

• effects on the absorption maximum wavelengths of the closed forms were not remarkable. The tendency observed was of the absorption maximum wavelength being a few nanometers longer in less polar toluene than for the other solvents. When the substituents on the terminal phenyl rings are electron-withdrawing

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• analysis which gives information about solution anion binding trends, the authors found that the cavity size of macrocycle, solvent effects and strength of electrostatic interactions notably affect the observed anion recognition processes [52]. 2.6.1. 1,2,3-Triazolium macrocycles with additional H-bond

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

• -withdrawing groups. Subsequently, we measured the UV–vis spectra of thioxanthylium salts. As shown in Figure 2, almost all measured UV–vis spectra are nearly identical in spite of different substituents on the benzene ring at the 9-position of the thioxanthylium core. Moreover, when the solvent effects were

Functional panchromatic BODIPY dyes with near-infrared absorption: design, synthesis, characterization and use in dye-sensitized solar cells

• Quentin Huaulmé,
• Cyril Aumaitre,
• Outi Vilhelmiina Kontkanen,
• David Beljonne,
• Alexandra Sutter,
• Gilles Ulrich,
• Renaud Demadrille and
• Nicolas Leclerc

Beilstein J. Org. Chem. 2019, 15, 1758–1768, doi:10.3762/bjoc.15.169

• thiophene ring. As we are dealing with charge-transfer electronic excitations, we have adopted a tuned range-separated CAM-B3LYP functional and the polarizable continuum model (PCM) to account for (implicit) solvent effects (in THF). The one-electron energy diagram reported in Figure 2 shows that: (i

Transient and intermediate carbocations in ruthenium tetroxide oxidation of saturated rings

• Manuel Pedrón,
• Laura Legnani,
• Maria-Assunta Chiacchio,
• Pierluigi Caramella,
• Tomás Tejero and
• Pedro Merino

Beilstein J. Org. Chem. 2019, 15, 1552–1562, doi:10.3762/bjoc.15.158

• ]. Computations were done using the B3LYP functional [48][49] in conjunction with Grimme’s dispersion correction [50][51] (henceforth referred to as B3LYP-d3bj). The standard basis set Def2SVP was employed [52][53]. For the purpose of comparison optimizations at gas phase and considering solvent effects (both

• point calculations at the 3ξ level of theory, using the Def2TZVP basis set and considering solvent effects, were carried out over optimized geometries to obtain more accurate energy values. The electronic structures of stationary points were analyzed by the topological analysis of the gradient field of

• considering solvent effects for acetonitrile and water and their corresponding energy values were calculated at the same level. Since the experimental conditions for the oxidation reactions usually involve a polar medium containing water, all discussions were based on data obtained considering solvent effects

Strong hyperconjugative interactions limit solvent and substituent influence on conformational equilibrium: the case of cis-2-halocyclohexylamines

• Camila B. Francisco,
• Cleverton S. Fernandes,
• Ulisses Z. de Melo,
• Roberto Rittner,
• Gisele F. Gauze and
• Ernani A. Basso

Beilstein J. Org. Chem. 2019, 15, 818–829, doi:10.3762/bjoc.15.79

• preference for the ea conformer in cis-2-halocyclohexylamines, being strong enough to restrain the shift in the equilibrium due to other factors such as steric repulsion or solvent effects. Keywords: conformational equilibrium; cyclohexane derivatives; dynamic NMR; hyperconjugation; principal component

• generalizations [2][3][4][5][6][7][8][9]. In the case of cis-2-halocyclohexylamines, the balance of interactions occurs between an amine group, which is known to be sensitive to the solvent [2][10][11], and the halogen, where the size increases considerably from F to I. Batchelor reported the solvent effects on

• the populations were 95, 94 and 91% for F, Cl and Br, respectively. These results clearly show that the equilibrium is non-sensitive to halogen size and solvent effects. A similar axial preference of cyclohexane halo derivatives was observed by Basso and co-workers in cis-2-halocyclohexanols [14], and

Study on the regioselectivity of the N-ethylation reaction of N-benzyl-4-oxo-1,4-dihydroquinoline-3-carboxamide

• Pedro N. Batalha,
• Luana da S. M. Forezi,
• Maria Clara R. Freitas,
• Nathalia M. de C. Tolentino,
• Ednilsom Orestes,
• José Walkimar de M. Carneiro,
• Fernanda da C. S. Boechat and
• Maria Cecília B. V. de Souza

Beilstein J. Org. Chem. 2019, 15, 388–400, doi:10.3762/bjoc.15.35

• compared in gas and condensed phase using water and DMSO. The solvent effects were included according to the polarized continuum solvation model (IEFPCM) [27][28]. The presence of the base used in the synthesis was also taken into consideration within both equilibria (Scheme 4 and Table 2). From these

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

• were obtained by single point calculations on the optimised geometries with the M06 functional [64] and the TZVP basis set [65], and solvent effects were estimated with the polarisable continuous solvation model PCM using dichloromethane as solvent [66][67]. The reported free energies in this work

Diazirine-functionalized mannosides for photoaffinity labeling: trouble with FimH

• Femke Beiroth,
• Tomas Koudelka,
• Thorsten Overath,
• Stefan D. Knight,
• Andreas Tholey and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1890–1900, doi:10.3762/bjoc.14.163

• X-ray crystallography, studies in solution add valuable information in molecular recognition studies as they take molecular dynamics as well as solvent effects into consideration. In the latter respect, photoaffinity labeling has evolved as a useful tool for studies under physiological conditions [1

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

• Rakesh Puttreddy,
• Ngong Kodiah Beyeh,
• S. Maryamdokht Taimoory,
• Daniel Meister,
• John F. Trant and
• Kari Rissanen

Beilstein J. Org. Chem. 2018, 14, 1723–1733, doi:10.3762/bjoc.14.146

• , has investigated the impact of host cavity flexibility, guest’s steric and electronic demands, and solvent effects, in both solution and the solid state [36][37][38]. For example, we recently studied C-ethyl-2-bromoresorcinarene (BrC2) [39] and C-propyl-2-bromoresorcinarene (BrC3) [40] to understand

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

• the M06-2X exchange-correlation functional together with the def2-TZVP basis set in the presence of a solvent environment implemented in the Gaussian 09 program package. The solvent effects were taken into account via the Polarisable Continuum Model (PCM) using the integral equation formalism variant

A three-armed cryptand with triazine and pyridine units: synthesis, structure and complexation with polycyclic aromatic compounds

• Claudia Lar,
• Adrian Woiczechowski-Pop,
• Attila Bende,
• Ioana Georgeta Grosu,
• Natalia Miklášová,
• Elena Bogdan,
• Niculina Daniela Hădade,
• Anamaria Terec and
• Ion Grosu

Beilstein J. Org. Chem. 2018, 14, 1370–1377, doi:10.3762/bjoc.14.115

• experimental (the order of the association constants) and theoretical (the magnitude of the binding energies) results, the intermolecular interaction energies were recomputed considering solvent effects induced by the DMSO solvent environment. Accordingly, the intermolecular interaction energies for the

London dispersion as important factor for the stabilization of (Z)-azobenzenes in the presence of hydrogen bonding

• Andreas H. Heindl,
• Raffael C. Wende and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2018, 14, 1238–1243, doi:10.3762/bjoc.14.106

• and solvent effects. In general, intramolecular hydrogen bonds were found to have the strongest influence on the observed thermal Z→E isomerization half-lives. However, LD becomes the decisive factor in polar solvents in which hydrogen bonding plays a minor role. This study demonstrates the importance

Polysubstituted ferrocenes as tunable redox mediators

• Sven D. Waniek,
• Jan Klett,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2018, 14, 1004–1015, doi:10.3762/bjoc.14.86

• functional [91][92][93] and employ the RIJCOSX approximation [94][95]. Relativistic effects were calculated at the zeroth order regular approximation (ZORA) level [96]. The ZORA keyword automatically invokes relativistically adjusted basis sets. To account for solvent effects, a conductor-like screening

Novel amide-functionalized chloramphenicol base bifunctional organocatalysts for enantioselective alcoholysis of meso-cyclic anhydrides

• Lingjun Xu,
• Shuwen Han,
• Linjie Yan,
• Haifeng Wang,
• Haihui Peng and
• Fener Chen

Beilstein J. Org. Chem. 2018, 14, 309–317, doi:10.3762/bjoc.14.19

• 10–16). Notably, with methyl-protected catalyst 7q, this reaction proceeded with longer reaction time but with decreased enantioselectivity, suggesting the effects of a bulky ether group (Table 1, entry 17). Solvent effects were then evaluated and aprotic solvent performed better than protic solvents

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-a]pyrimidine/2-azidopyrimidines

• Elisandra Scapin,
• Paulo R. S. Salbego,
• Caroline R. Bender,
• Alexandre R. Meyer,
• Anderson B. Pagliari,
• Tainára Orlando,
• Geórgia C. Zimmer,
• Clarissa P. Frizzo,
• Helio G. Bonacorso,
• Nilo Zanatta and
• Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 2396–2407, doi:10.3762/bjoc.13.237

• energy data about the stabilization of the different forms, solvent effects, and shows that the azide–tetrazole transformation is initiated by a p–π atomic orbital overlap rather than an electrostatic attraction process [48]. To detect which form is more stable in the solid state, quantum mechanical

Cycloheximide congeners produced by Streptomyces sp. SC0581 and photoinduced interconversion between (E)- and (Z)-2,3-dehydroanhydrocycloheximides

• Li Yang,
• Ping Wu,
• Jinghua Xue,
• Huitong Tan,
• Zheng Zhang and
• Xiaoyi Wei

Beilstein J. Org. Chem. 2017, 13, 1039–1049, doi:10.3762/bjoc.13.103

• accurate energies of these conformers in MeOH were obtained with the B3LYP-D3/def2-TZVP method. Solvent effects were taken into account by using polarizable continuum model (PCM). The TDDFT calculations were performed using the hybrid BHandHLYP [26], M11 [27], and/or PBE1PBE [28][29] functionals, and

• used. Solvent effects were treated using PCM. To build 3D conformers of 2a and 3a, the global energy minima of 2 and 3, obtained in above ECD computations, were used and their glutarimide ring was replaced by a hydrogen atom. The built conformers were subjected to geometry optimizations to obtain the

Conformational study of L-methionine and L-cysteine derivatives through quantum chemical calculations and ³J_HH coupling constant analyses

• Weslley G. D. P. Silva,
• Carolyne B. Braga and
• Roberto Rittner

Beilstein J. Org. Chem. 2017, 13, 925–937, doi:10.3762/bjoc.13.94

• conformational analysis of esterified and N-acetylated derivatives of L-methionine and L-cysteine using a combination of 1H NMR and electronic structure calculations is reported. The geometries and energies of the most stable conformers in isolated phase and taking into account the implicit solvent effects

• solvents. The results showed that the conformational stability of the esterified derivatives is not very sensitive to solvent effects, whereas the conformational equilibrium of the N-acetylated derivatives changes in the presence of solvent. According to the natural bond orbital (NBO), quantum theory of

• its population reduced from almost 100% in isolated phase to 67.7% in DMSO. In general, these population changes for the geometries of compounds 3 and 4 indicate that their conformational equilibria are sensitive to solvent effects. The conformational changes induced by the solvent were also

Synthesis and optical properties of new 5'-aryl-substituted 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazoles

• Anastasia S. Kostyuchenko,
• Tatyana Yu. Zheleznova,
• Anton J. Stasyuk,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2017, 13, 313–322, doi:10.3762/bjoc.13.34

• derivatives having a thienyl (15c), phenyl (15d), naphthalen-1-yl (15e) and anthracen-9-yl (15f) aromatic substituent. The DFT/TDDFT approach at the B3LYP/Def2-SVPD level of theory coupled with polarizable continuum model of solvent effects and using the integral equation formalism variant (IEFPCM) was

Total synthesis of a Streptococcus pneumoniae serotype 12F CPS repeating unit hexasaccharide

• Peter H. Seeberger,
• Claney L. Pereira and
• Subramanian Govindan

Beilstein J. Org. Chem. 2017, 13, 164–173, doi:10.3762/bjoc.13.19

• participation groups and solvent effects. It lends further credence to the linear assembly concept in which one monosaccharide unit at a time is incorporated, and which serves as the basis for automated glycan assembly [43]. With the synthetically sourced hexasaccharide repeating unit in hand detailed

Methylenelactide: vinyl polymerization and spatial reactivity effects

• Judita Britner and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 2378–2389, doi:10.3762/bjoc.12.232

• ) = 2914 cm−1). Figure 4 shows the IR spectra of MLA and of the obtained poly(MLA). To evaluate some kinetic solvent effects of the discussed self-initiated polymerization reactions of MLA, the kinetics of the AIBN-initiated and initiator-free radical polymerizations of MLA were repeated in less polar 1,4

Experimental and theoretical investigations into the stability of cyclic aminals

• Edgar Sawatzky,
• Antonios Drakopoulos,
• Martin Rölz,
• Christoph Sotriffer,
• Bernd Engels and
• Michael Decker

Beilstein J. Org. Chem. 2016, 12, 2280–2292, doi:10.3762/bjoc.12.221

• cc-PVTZ basis sets [42][43] and all computations were performed with TURBOMOLE [44]. Solvent effects were mimicked by the Screening Model (COSMO) for water [45]. As expected, N-3 was found to be more basic for all test compounds, with the exception of 9c. Therefore, in the following text, only the

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• route for the synthesis of 20a. Synthesis of THQ 21 and DHQ 22 using borane·dimethyl sulphide complex or DIBAL, respectively. Postulated mechanism for the formation of 22 using DIBAL. Miyaura borylation of 21 and 22 to give crystalline boronic esters 29 and 30. Temperature and solvent effects from the

One-pot synthesis of tetracyclic fused imidazo[1,2-a]pyridines via a three-component reaction

• Bo Yang,
• Chuanye Tao,
• Taofeng Shao,
• Jianxian Gong and
• Chao Che

Beilstein J. Org. Chem. 2016, 12, 1487–1492, doi:10.3762/bjoc.12.145

• % yield. Performing the reaction under reflux conditions slightly improved the yield to 11%. We next examined solvent effects in this MCR reaction and various solvents were screened, as summarized in Table 1. We observed that protic solvents with medium polarity can facilitate the reaction by product

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• ligands. Solvent effects on asymmetric redox bicycloisomerization reaction as described in [43]. Effect of the catalyst structure on the redox bicycloisomerization as described in [43]. Comparison of complex 1 to other catalyst systems as described in [43]. Effect of the nitrogen protecting group on