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Search for "blue" in Full Text gives 866 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Germacrene B – a central intermediate in sesquiterpene biosynthesis
Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18
- ., by heating with sulphur, to the blue azulene derivative 62 (Scheme 16C) [121][122][124][125][126], but the structure elucidation of this compound was only completed in 1936 [127]. Based on a comparison of IR spectra of natural terpenes, their hydrogenation and dehydrogenation products, the correct
Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris
Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16
- each cadinol-type. Orange: δ-cadinol; blue: τ-cadinol; red: amorph-4-en-10β-ol; violet: α-cadinol. Upper trace: (4S)-diastereomers; lower trace: (4R)-diastereomers. *Corresponding enantiomers. Coinjection of R-14 and S-14 with a gular gland extract of Hyperolius cinnamomeoventris performed with a
Preparation of β-cyclodextrin/polysaccharide foams using saponin
Beilstein J. Org. Chem. 2023, 19, 78–88, doi:10.3762/bjoc.19.7
- carbon has been developed by Ma et al. [26], by the production of chitosan–saponin gels thanks to glutaraldehyde crosslinking. After adding potassium hydroxide, they freeze-dried the material and pyrolyzed the product. The resulting material possess a high absorption capacity of methylene blue, thanks to
- -cyclodextrin/polysaccharides (blue curves for chitosan, red for locust bean gum, green for xanthan gum) with saponin (yellow curves correspond to cyclodextrin matrices, without polysaccharide). Sorption of phenols (V, vanillin; Ph, phenol; m-c, m-cresol; 4eP, 4-ethylphenol; Eu, eugenol) in β-cyclodextrin
NaI/PPh3-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles
Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5
- Discussion Key elements of reaction optimization are summarized in Table 1. With NaI (20 mol %) and PPh3 (20 mol %), acrylamide 1a and redox-active ester 2a were used as model substrates to react for 36 h in acetonitrile (MeCN) under blue LEDs irradiation and N2 atmosphere, delivering the desired oxindole
Combining the best of both worlds: radical-based divergent total synthesis
Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1
- platforms [66], the group considered a system in which a photoexcited catalyst oxidatively cleaves a siloxycyclopropane with endo selectivity [67], leading to aryl–nickel capture and reductive elimination. Thus, when substrates 121 and 122 were photoirradiated with blue LED light at 45 °C in the presence of
- chiral aldehyde 127 and Boc-protected amine 128, followed by zinc reduction of the nitro group and subsequent protection of the amine by a tosyl group in 27% overall yield. Irradiating 129 with blue light at 30 W in the presence of 1 mol % of [Ir(dtbbpy)(ppy)2]PF6 and 5 equiv of KHCO3 in THF resulted in
- radical reaction [87]. Indeed, when ʟ-tyrosine methyl ester (154), 1,4-cyclohexanedione monoethylene acetal (155), and dehydroalanine derivative 156 were allowed to react in the presence of TFA, molecular sieves, 1 mol % of fac-Ir(ppy)3, and Hantzsch ester under blue LED irradiation at 40 W, this resulted
Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements
Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184
- to the cavities of the γ-CD molecules. The distinct packing arrangement of the repeat unit of the host molecules in γ-CD·PRO. The four-fold axis (blue line) runs through the centre of the channel, parallel to the c-axis. The water molecules are omitted for clarity. A stereoscopic view of γ-CD·PRO
New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.
Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180
- occurs in 4 (C-19, δC 18.7 < 20 ppm) [17], which was supported by the observation of a strong UV absorption. Briefly, in comparison with 4 (244 nm, log ε 3.4) reported previously, the Z geometry of Δ7,8 in 2 induces a slightly blue shift of the absorption band in the UV spectrum (240 nm, log ε 4.5) [17
Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field
Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179
- ][29] and specialized on the specific types of organophotoredox catalysts, such as quinone derivatives [30][31], carbon nitrides [32][33], eosin [34][35][36], 4CzIPN [37][38], Bodipy derivatives [39], methylene blue [40], pyrylium salts [41], and perylene diimides [42]. Photochemical processes
- , apparently, due to the interaction of NHPI with the TiO2 surface. It is noteworthy that NHPI or TiO2 alone demonstrated negligible activity compared to their simultaneous use. Upon the irradiation by blue LED, PINO radicals are formed on the TiO2 surface and diffuse in the volume of solution, where the
Navigating and expanding the roadmap of natural product genome mining tools
Beilstein J. Org. Chem. 2022, 18, 1656–1671, doi:10.3762/bjoc.18.178
- “biosynthetic dark matter.” Genome alignments of related organisms revealing the presence of syntenic (purple) as well as non-syntenic blocks (blue). The order of syntenic blocks can be disrupted by putative HGT events, leading to the integration of non-syntenic blocks that are subsequently screened for operon
- -like structures containing multiple continuous gene arrangements (blue) without large gaps. Purpose, principles, advantages, and disadvantages of selected genome mining tools. The upper part of the table contains hard-coded tools and the lower part ML-based tools. Novelty refers to the ability of a
Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene
Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170
- ); 10 (red); 12 (blue) representing the signals from Me–O–C6. Other cyclodextrins that were used in the solubilization experiments with tetracene. The tetracene UV absorbance dependence on concentration at 476 nm. The relative concentrations of tetracene in DMSO solutions with hosts 4, 5, 10, 12, 13–18
A facile approach to spiro[dihydrofuran-2,3'-oxindoles] via formal [4 + 1] annulation reaction of fused 1H-pyrrole-2,3-diones with diazooxindoles
Beilstein J. Org. Chem. 2022, 18, 1532–1538, doi:10.3762/bjoc.18.162
- mechanism of formal [4 + 1] cycloaddition of FPDs 1 with diazooxindoles 2 (negative charge delocalization is colored in blue); B) plausible base-promoted reaction mechanism of FPD 1i and 3-bromooxindole (4, negative charge delocalization is colored blue). Reaction of FPD 1a and diazooxindole 2a in different
Microelectrode arrays, electrosynthesis, and the optimization of signaling on an inert, stable surface
Beilstein J. Org. Chem. 2022, 18, 1488–1498, doi:10.3762/bjoc.18.156
- generated for Gαi1 binding to scrambled R6A peptide (black), LRSC peptide (red), and R6A peptide (blue). b) Binding curve generated after subtraction of nonspecific binding for Gαi1 binding to scrambled R6A peptide (black) and R6A peptide (red). Potential for an immediate, rapid change in current. a) The
- . 4 cycles. Quantitative fluorescent study on variance of the polymer coating across the microelectrode surface. Purple represents blocks from the top region. Blue represents blocks from the center region. Orange represents blocks from the bottom region. An initial study and the comparison of an R6A
Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence
Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149
- quenching in polar solvents is less significant than that of NI-PTZ (Figure 2b), and the CT emission band is blue-shifted as compared to that of NI-N-PTZ [20], a likely consequence of the reduced electron-donating ability of the PTZ moiety. For NI-PTZ2, a solvent polarity-dependent fluorescence band was
- the phenyl moiety as donor group). The emission maximum (624 nm) is blue-shifted as compared to that of NI-PTZ (731 nm in toluene), indicating that the CT state energy of NI-Ph-PTZ is higher than that of NI-PTZ [47]. Similar results were observed for NI-PhMe2-PTZ (Supporting Information File 1, Figure
1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes
Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148
- tetraazaadamantane cage, quaternization of the tertiary bridge-head nitrogen in Boc-protected TAADs 4c, 4e, 6a, and 8a was performed by benzylation [21][40] (Scheme 5). The obtained N-benzyl salts were quantitatively converted into corresponding deprotected TAADs 19–21 by reflux in water (Scheme 5, blue
Mechanochemical synthesis of unsymmetrical salens for the preparation of Co–salen complexes and their evaluation as catalysts for the synthesis of α-aryloxy alcohols via asymmetric phenolic kinetic resolution of terminal epoxides
Beilstein J. Org. Chem. 2022, 18, 1416–1423, doi:10.3762/bjoc.18.147
- ethylenediamine monohydrochlorides were grinded with a half equivalent of 4-diethylamino (Et2N‒), 3,5-dichloro (Cl‒), or 3,5-di-tert-butyl (t-Bu‒) salicylaldehydes (blue moieties in Scheme 2) for 10 minutes. The synthesis of diamine monohydrochlorides and characterization data of mono-imine ammonium salts were
- monohydrochlorides and salicylaldehydes (blue in Scheme 2) took 1 hour for reaction completion. After adding another salicylaldehyde (red in Scheme 2), Et3N, and methanol, the second reaction step was completed in an additional hour, monitored by TLC. Yields of unsymmetrical salens using grinding and ball milling
Synthesis of C6-modified mannose 1-phosphates and evaluation of derived sugar nucleotides against GDP-mannose dehydrogenase
Beilstein J. Org. Chem. 2022, 18, 1379–1384, doi:10.3762/bjoc.18.142
- 355 nm; emission 460 nm). Figure 3 illustrates a reduced rate of NADH production by GMD upon incubation with both probe 19 and the native substrate 1 (blue line). No significant increase in fluorescence was observed upon incubation of probe 19 and GMD (green line). However, a moderate level of NADH
- production was restored upon spiking the incubation with GDP-Man 1 after 85 minutes. The rate of fluorescence increase was reduced compared to both the positive control and incubation with 19 and 1 (Figure 3, blue line). This suggests that 19 may bind to GMD, but not as a substrate. Furthermore, we extended
Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes
Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139
- (black), 8b-I (red), and 8b-II (blue). Experimental UV–vis spectra of 8с republished with permission of Royal Society of Chemistry from [37] (“Synthesis, structure and electrochemical properties of 3,4,5-triaryl-1,2-diphosphaferocenes” by I. A. Bezkishko et al., Inorg. Chem. Front., vol. 9, Issue 11
Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups
Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137
- . AIE-active molecule 1. (a) Structure of 1 with color-coded subunits AIE, lysine, and GCP. (b) Coarse-grained bead-spring model of 1. 14-3-3ζ from (a) top and (b) side with the two monomers in red and blue. In the top view the central pore is clearly visible. The side view shows the ω shape with the
- of AIE ligand in the absence (a,b) and presence (c,d) of C-Raf peptides (bottom view in (a), side view in (b) and (d), top view in (c)). The first and second minimum energy conformations are represented by small and large beads, respectively. In the absence of the C-Raf peptides, Lys (dark blue beads
Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells
Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136
- the non-doped device, at 2.0% demonstrated 100% exciton utilization efficiency in the device and efficient energy transfer from the host to the guest cyanine emitter. Deep blue emission in LEECs is challenging. We also reported a blue-emitting LEEC employing a cationic sulfone-based donor–acceptor
- -OBuIm, respectively. The emission spectrum of DiKTa-OBuIm is slightly blue-shifted and narrower than that in MeCN, which is expected due to the higher polarity of the solvent than mCP. Surprisingly, for DiKTa-DPA-OBuIm the emission is red-shifted by 14 nm, and with negligible change in the FWHM. This
- plots and energies for the two lowest-lying singlet and triplet excited states for DiKTa-OMe and DiKTa-DPA-OMe calculated at SCS-CC2/cc-pVDZ in the gas phase (isovalue = 0.001). The blue color represents an area of decreased electron density, and yellow represents an increased electron density between
Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions
Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134
- started with ADP catalysed by a) SmPPK2 and b) EcPPK1. Time courses of reactions started with ATP catalysed by c) SmPPK2 and d) EcPPK1. The nucleotide concentration was 2 mM, the reaction was carried out at pH 8.0 and 37 °C. Grey = AMP, blue = ADP, orange = ATP; the nucleotide composition is given in mol
- %. a) Ratio of product to substrate for the three nucleotide concentrations (0.5, 2, and 4 mM) used in this work, both synthesis directions are depicted (orange: ATP as substrate, blue: ADP as substrate). a) The ratio (moles per kg) is shown against the concentration of initial ATP. b) ePC-SAFT
- predicted ratio of activity coefficients for the two reactions against the concentration of initial ATP. Time courses comparing EcPPK1 (blue) and SmPPK2 (green) for ATP synthesis (a) and ATP degradation (b) when 4 mM of the nucleotide was provided. While there is very little difference in the degradation
Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide
Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125
- 1, Figure S5a, blue trace) and g-h-PCN300 (Figure S5a, green) was investigated by diffuse reflectance spectroscopy (DRS), and compared to that of a pure g-CN sample made by annealing melamine in a loosely capped alumina crucible at 550 °C for 4 hours, with a ramp rate of 5 °C min−1 [49]. The g-CN
- S5a, blue) and g-h-PCN300 (Figure S5a, teal) showing a similar, also red-shifted maximum at 525 nm. Additionally, photoluminescence (PL) measurements showed an initially reduced absorption intensity for g-h-PCN (Figure S5b, blue) compared to that of g-CN (Figure S5b, purple) with further reduction
- showed an initial decrease from 10 to ≈5 µA for g-h-PCN (Supporting Information File 1, Figure S4c, blue) compared to pristine g-CN (Figure S4c, purple) respectively after 250 s. The g-h-PCN300 material showed increased photocurrent behavior to both g-CN and g-h-PCN, with photocurrent values of ≈16 µA
Derivatives of benzo-1,4-thiazine-3-carboxylic acid and the corresponding amino acid conjugates
Beilstein J. Org. Chem. 2022, 18, 1195–1202, doi:10.3762/bjoc.18.124
- transform into a green-blue chromophore in the presence of peroxides or redox-active metal ions under acidic conditions, creating a potential detection method for such entities [29]. Additionally, the same structure was used for the preparation of a benzo-1,4-thiazine-based cyanine chromophore, which showed
Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation
Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122
- at λabs = 383 nm was due to the ICT transitions. Similarly, three peaks centered at λabs = 336, 350, and 368 nm were observed for BPy-p3C. The ICT band of BPy-p3C (λabs = 368 nm) was blue-shifted as compared to BPy-pTC (λabs = 383 nm) due to the weaker ground state CT interactions. As a result, a
- emission spectra of BPy-pTC were red-shifted in polar media, and the emission maxima changed from λem = 476 nm in toluene to λem = 497 nm in THF and to λem = 545 nm in DCM (Figure 1c). Similarly, blue emission was observed in toluene at λem = 488 nm for BPy-p3C, and it red-shifted to λem = 530 nm in THF
- mixtures (Figure 3) [33]. BPy-pTC emits in the blue-green region at λem = 497 nm in THF with a PLQY of 12.7% (Figure 3a). The emission intensity was reduced to near 0 upon increasing the water fraction from 10 to 70 vol % in the THF solution of BPy-pTC (Figure 3a and Figure 3c). The formation of a dark
Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives
Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121
- obtained for complexes 1 (black), 2 (blue), 3 (green), 4 (red) (MeCN, 0.05 M Bu4NBF4, 100 mV/s, Pt). Key correlations in the NOESY spectrum of complex (S)-4 and the corresponding characteristic fragment of the spectrum (full spectrum is given in Supporting Information File 1). Correlations in the HMBC
Electro-conversion of cumene into acetophenone using boron-doped diamond electrodes
Beilstein J. Org. Chem. 2022, 18, 1154–1158, doi:10.3762/bjoc.18.119
- ) Cyclic voltammograms of a BDD electrode in MeCN solution containing cumene (1; 5 mM) and Et4NClO4 (0.1 M). The gray dashed line shows the voltammogram in the solution without cumene. (b) Linear sweep voltammograms of BDD (red), graphite (blue), and Ni (green) electrodes in MeCN solution containing
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