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

• Grubbs 2-type (5) metal carbenes with pyridinyl alcoholato ligands for the 1-octene metathesis reaction (Figure 3) [10][11][12][13][14]. The incorporation of pyridinyl-alcoholato ligands in the Grubbs-type precatalysts has shown an increase in the thermal stability, activity and lifetime of the

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

• other N-alkyl (neopentyl and neophyl) and N-aryl (mesityl) substituents, was published later [61]. Among these novel Hoveyda-type catalysts 193–198 (Figure 35), 198 was of particular interest due to its excellent thermal stability in solution and to the high efficiency in the ethenolysis of ethyl oleate

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• handling, and even reusability [34]. Ionic liquids (ILs) have been extensively reported as green solvents in organic transformations, owing to their considerable properties such as the ability to dissolve a wide range of substances, very low vapor pressure, high thermal stability, recyclability, non

Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine

• Piotr Pomarański,
• Piotr Roszkowski,
• Jan K. Maurin,
• Armand Budzianowski and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2018, 14, 2384–2393, doi:10.3762/bjoc.14.214

• ). Considering further applications of atropisomeric arylated pyridines in the design of new materials like molecular switches [4], it would be desirable to estimate their thermal stability. We therefore performed kinetic experiments in order to establish the value of the barrier to rotation in the

Practical tetrafluoroethylene fragment installation through a coupling reaction of (1,1,2,2-tetrafluorobut-3-en-1-yl)zinc bromide with various electrophiles

• Ken Tamamoto,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 2375–2383, doi:10.3762/bjoc.14.213

• the CF2CF2 unit between two cyclohexane rings caused significant enhancement in thermal stability in a liquid crystalline phase (Figure 1c) [11]. In addition to the development of a convenient access to CF2CF2-containing pyranoses [12], our group also showed that tricyclic mesogens with a CF2CF2

• that possesses higher thermal stability than the corresponding organolithium or -magnesium species due to the almost covalent C–Zn bond [29][30]. Moreover, organozinc reagents can be easily transformed to the “reactive” species, through a transmetallation process with a transition metal (e.g., Pd or Cu

• 1.5 years in the refrigerator [35]. In order to examine the stability of 2-Zn in more detail, we quantitatively evaluated the thermal stability of 2-Zn under various temperature conditions (Figure 2). After a given duration, the recovery yield of 2-Zn was determined by 19F NMR analysis using an

A general and atom-efficient continuous-flow approach to prepare amines, amides and imines via reactive N-chloramines

• Katherine E. Jolley,
• Michael R. Chapman and
• A. John Blacker

Beilstein J. Org. Chem. 2018, 14, 2220–2228, doi:10.3762/bjoc.14.196

• -toluenesulfonamide (11) was investigated as substrate. Differential scanning calorimetry (DSC) was used to assess the thermal stability of 11, which melts at 78 °C and decomposes between 160–200 °C. This profile peaks at 188 °C, corresponding to an enthalpy of decomposition of −84.7 kJ mol−1 (see Supporting

Functionalization of graphene: does the organic chemistry matter?

• Artur Kasprzak,
• Agnieszka Zuchowska and
• Magdalena Poplawska

Beilstein J. Org. Chem. 2018, 14, 2018–2026, doi:10.3762/bjoc.14.177

• and hydrogen bonding-dependent adsorption of glucose on the RGO surface results in a shift of the absorption bands coming from the C=O of RGO (from 1724 cm−1 to 1735 cm−1). Another consideration is that this process further influences the obtained material’s morphology, properties and thermal

• stability [41][42]. Additionally, some researchers have used the acid catalysis [39] or grinding-induced process [40] for the esterification reaction, and the changes in the spectra (e.g., IR, XPS) were not prominent enough to imply the formation of covalent ester-type linkages. In the grinding-induced case

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• [21][22][23][24][25][26][27]. The properties of CyNSs, in terms of physical and mechanical features, porosity, thermal stability and adsorption or release abilities, may be modulated up to a certain extent by a sensible choice of the linker unit, depending on its length and possible functionalization

• surface. Finally, DSC experiments were performed in order to evaluate the behavior on heating and the thermal stability of the materials. We found out that both the parent Ca-OP monomer and the CaNSs materials decompose at ca. 230 °C. pH Dependent absorption abilities The possible pH dependent abilities

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

• complexes exhibited high thermal stability since thermogravimetric analysis (TGA) showed a weight loss of only 5% at temperatures in the range 436–463 °C. An intense and structured emission in the green region with λem = 500–507 nm and PLQY = 0.6–0.78 was recorded when the complexes were used as dopant in

• and high thermal stability. Unfortunately, going from dilute solution to neat solid-state samples, PLQY values dramatically dropped to values as low as 0.10–0.02 that might point to strong intermolecular interaction and TTA phenomena. The tendency toward aggregation for complex 44 and 46 in condensed

Oligonucleotide analogues with cationic backbone linkages

• Melissa Meng and
• Christian Ducho

Beilstein J. Org. Chem. 2018, 14, 1293–1308, doi:10.3762/bjoc.14.111

• reported to be above 80 °C whereas a comparable DNA–DNA duplex was only stable up to 13 °C. DNmt-T5 complexes with native RNA-APoly showed an even higher thermal stability. Job plot analysis revealed the formation of triple-stranded complexes between the DNmt pentamer and DNA-APoly or RNA-APoly

• . Furthermore, a pronounced drop in thermal stability of DNmt–DNA complexes containing 50% T–C mismatches and also for congeners containing 20% T–C mismatches was described [71]. In CD spectroscopic studies performed on the thymidinyl DNmt pentamer, Bruice et al. further confirmed the base-pairing specificity

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

• [12] and show reversible isomerization from the thermally stable E- to the Z-isomer upon irradiation with UV light. The metastable Z-azobenzene re-isomerizes to the E-conformer either thermally or upon irradiation with visible light [13][14]. Interestingly, the thermal stability of azobenzene isomers

Two novel blue phosphorescent host materials containing phenothiazine-5,5-dioxide structure derivatives

• Feng-Ming Xie,
• Qingdong Ou,
• Qiang Zhang,
• Jiang-Kun Zhang,
• Guo-Liang Dai,
• Xin Zhao and
• Huai-Xin Wei

Beilstein J. Org. Chem. 2018, 14, 869–874, doi:10.3762/bjoc.14.73

• . Moreover, their fluorescence emission peaks are in the blue fluorescence region at 408 nm and the fluorescence quantum efficiency (Φ) of CEPDO and CBPDO were 62.5% and 59.7%, respectively. Both CEPDO and CBPDO showed very high thermal stability with decomposition temperatures (Td) of 409 and 396 °C as well

• time, the photophysical properties, electrochemical properties and their thermal stability were studied and the expected results were obtained. Results and Discussion Synthesis and theoretical calculations The synthesis route for CEPDO and CBPDO is shown in Scheme 1. The detailed synthesis procedures

• scanning calorimetry (DSC) under nitrogen atmosphere at a scanning rate of 10 °C/min and the results are shown in Figure 4. Both CEPDO and CBPDO show very high thermal stability with decomposition temperatures (Td) of 409 and 396 °C and glass transition temperatures (Tg) of 167 and 138 °C, respectively

Mannich base-connected syntheses mediated by ortho-quinone methides

• Petra Barta,
• Ferenc Fülöp and
• István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

• reactions is definitely more advantageous. Ionic liquids have also attracted considerable attention due to their „green chemistry” values, including reusability, high thermal stability and non-inflammability. Hajipour et al. reported the one-pot synthesis of 1-amidoalkyl-2-naphthols catalysed by N-(4

Polarization spectroscopy methods in the determination of interactions of small molecules with nucleic acids – tutorial

• Tamara Šmidlehner,
• Ivo Piantanida and
• Gennaro Pescitelli

Beilstein J. Org. Chem. 2018, 14, 84–105, doi:10.3762/bjoc.14.5

• increase in the cuvette, usually best seen in the long-wavelength range of the spectrum, is a clear evidence of precipitation or colloid/aggregate formation in the cuvette, which completely hampers further experiments. The characterization of the thermal stability of the ligand solution by collecting it’s

Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review

• Vânia André,
• Sílvia Quaresma,
• João Luís Ferreira da Silva and
• M. Teresa Duarte

Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239

• coordination networks of pharmaceuticals involving lanthanides, showing different types of architectures based on mono-, di-, tri- and hexametallic centers and 1D polymeric chains. These new compounds proved to be unstable under shelf conditions. With regard to their thermal stability these compounds lose

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

• high thermal stability and low volatility) of ILs can be considered. Reactions in [BMIM][BF4] and [HMIM][TsO] using p-toluenesulfonic acid (p-TsO) as a catalyst were unsuccessful and have been omitted from Table 1. The best conditions that were found for 1a and 5-aminotetrazole (2) were used for the

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• °C, respectively. The 2,5-thienylene linker decreased the melting point approximately by 40 °C (e.g., 2a/4a with Tm = 244/200 °C). End-capping the DPP derivative with a ferrocene donor brings improved thermal stability (e.g., compound 5b with the second highest Tm and Td values within the series b

• in modular way prepared by Suzuki–Miyaura, Migita–Stille, and Sonogashira cross-coupling reactions. The chromophores differ in the π-system extension as well as in the peripheral substitution. The thermal stability of 1–5 is mostly affected by the presence of acetylene linkers, 1,4-phenylene and 2,5

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• TFEO-ZnPc into a fluoropolymer markedly improves its thermal stability. In addition, the TFEO-ZnPc-supported fluoropolymer showed significantly lower fluorescence than monomeric TFEO-ZnPc. This suggests a strong electronic interaction among TFEO-Pc units, allowing for its application in photonic

Novel approach to hydroxy-group-containing porous organic polymers from bisphenol A

• Tao Wang,
• Yan-Chao Zhao,
• Li-Min Zhang,
• Yi Cui,
• Chang-Shan Zhang and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 2131–2137, doi:10.3762/bjoc.13.211

• obtained PPOPs are shown in the Scheme 1. All of the polymers are stable and insoluble in common organic solvents such as dichloromethane, ethanol, and acetone. Furthermore, the as-prepared materials exhibit a high thermal stability according to the results of TGA (Supporting Information File 1, Figure S1

An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• polymers from the polymerization of ethylene oxide [67]. Owing to their significant advantages, including widely commercial availability, biocompatibility, chemical and thermal stability and ease to be derived, PEGs have been widely used as phase-transfer catalysts (PTC) or in the preparation of water

Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

• Sadaf Hanif,
• Bernd Oschmann,
• Dmitri Spetter,
• Muhammad Nawaz Tahir,
• Wolfgang Tremel and
• Rudolf Zentel

Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163

• energy is needed to overcome the lattice energy and melt the salt. Ion liquids are also called “green solvents”, because of their low vapor pressure, fire resistance and thermal stability [4]. Beside this, they have a high ionic conductivity, large heat capacity and good thermal and chemical stability [5

Mechanochemical borylation of aryldiazonium salts; merging light and ball milling

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1463–1469, doi:10.3762/bjoc.13.144

• heating. NMR analysis of the molten 1d revealed the presence of 1-fluoro-4-iodobenzene (for details, see Supporting Information File 1). Therefore, the difference in melting point temperatures of the substrates and their thermal stability could have a direct correlation with the observed reactivity in the

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

• Qing Yin,
• Qi Chen,
• Li-Can Lu and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

• and SugPOP-2 are shown in Figures S2 and S3 (Supporting Information File 1) and show similar resonance intensities to SugPOP-3. All of the polymer samples show some common properties of cross-linked polymers such as stability and insolubility in common solvents. The thermal stability of SugPOP-1–3 was

• characterized by thermogravimetric analysis (TGA) under nitrogen atmosphere (Figure S4, Supporting Information File 1). The TGA plots show that the decomposition temperature of the polymers is at about 300 °C and there is 35% mass loss when the temperature reaches 800 °C, indicating good thermal stability of

• diffraction peaks suggest the formation of small-sized AgNPs. The actual loading capacity of Ag is 5.4 wt % as discerned by TGA under air atmosphere. Meanwhile, the AgNPs/SugPOP-1 composite exhibits about 2% mass loss at 310 °C and good thermal stability (Figure S7 in Supporting Information File 1). The

G-Protein coupled receptors: answers from simulations

• Timothy Clark

Beilstein J. Org. Chem. 2017, 13, 1071–1078, doi:10.3762/bjoc.13.106

• , polar fragment such as the T4 lysozyme [10][11] or other suitable protein fragments [12]. Other techniques used to obtain GPCR crystals include mutations to enhance the thermal stability [13], solubilization with custom detergents [14] or in conjunction with high-affinity ligands, which promote one

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• -C18pPhC18-PC is partially miscible with saturated phosphatidylcholines; however, closed lipid vesicles with an increased thermal stability were not found. Instead, bilayer fragments and disk-like aggregates are formed. Keywords: aggregation behaviour; bolaamphiphiles; bolalipids; membrane lipids; mixing

• -C16pPhC16-PC [36], which self-assembles at room temperature into small ellipsoidal micelles, and to PC-C17pPhC17-PC [35] that forms nanofibres with a significantly reduced thermal stability compared to PC-C32-PC. Unfortunately, the insertion of PC-C17pPhC17-PC into phospholipid bilayers composed of, e.g

• formation of disk-like aggregates in mixtures with DPPC and DSPC, respectively, with partly increased thermal stability [34]. The mixing behaviour of PC-C18pPhC18-PC with phosphatidylcholines was now studied by means of DSC and TEM. Additionally, one example of a bolalipid/phospholipid mixture was further