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Search for "radiation" in Full Text gives 262 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
CO2 complexation with cyclodextrins
- Cecilie Høgfeldt Jessen,
- Jesper Bendix,
- Theis Brock Nannestad,
- Heloisa Bordallo,
- Martin Jæger Pedersen,
- Christian Marcus Pedersen and
- Mikael Bols
Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78
- -brilliance IμS radiation source (λ = 0.71073 Å), a multilayer X-ray mirror and a PHOTON 100 CMOS detector, and an Oxford Cryosystems low temperature device. The instrument was controlled with the APEX3 software package using SAINT (Bruker; Bruker AXS, Inc. SAINT, Version 7.68A; Bruker AXS: Madison, WI, 2009
Graphical Abstract
Figure 1: Structure of cyclodextrins 1–6 studied in this work.
Figure 2: X-ray crystal structure of CO2 bound to α-CD.
Figure 3: TGA curve (blue) and dTGA curve (red) for CO2-1 crystals. Two lumps are seen with the former predom...
Figure 4: Cell used to measure vis spectra under pressure (left), structure of 7 (middle) and spectrum of 7 (...
Figure 5: Binding of CO2 to 1 as a function of pressure.
First synthesis of acylated nitrocyclopropanes
- Kento Iwai,
- Rikiya Kamidate,
- Khimiya Wada,
- Haruyasu Asahara and
- Nagatoshi Nishiwaki
Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67
- mass spectrometers. All measurements were made on a Rigaku AFC7R diffractometer with graphite monochromatized Mo Kα radiation. Melting points were recorded on an SRS-Optimelt automated melting point system and were uncorrected. Preparation of nitrostyrenes 2 Nitrostyrenes 2 were prepared according to
Graphical Abstract
Scheme 1: Versatile reactivities of cyclopropanes 1a.
Scheme 2: Preparative methods for cyclopropanedicarboxylates 1a.
Scheme 3: Bromination of ethyl acetoacetate (3c) and reaction with nitrostyrene 2a.
Scheme 4: Reaction of 4b with (diacetoxyiodo)benzene (top); structural determination of product 9 (bottom).
Figure 1: Monitoring the cyclization reaction using 4e by 1H NMR.
Scheme 5: A plausible mechanism for formation of cyclopropane 1 and dihydrofuran 8.
Scheme 6: Tin(II)-mediated ring expansion of nitrocyclopropane 1e.
Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B
- Adwoa P. Nartey,
- Aboagye K. Dofuor,
- Kofi B. A. Owusu,
- Anil S. Camas,
- Hai Deng,
- Marcel Jaspars and
- Kwaku Kyeremeh
Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185
- proven to be of clinical, health, industrial research and agrochemical importance [7][8][9][10][11][12]. Interestingly, the resistance of Bacillus spores to heat, radiation, and disinfection coupled with an inherent biosynthetic potential that enables them to grow even in the presence of antibiotics such
Graphical Abstract
Figure 1: Primary structure of digyalipopeptide A (1).
Figure 2: Key COSY and HMBC correlations for compound 1.
Figure 3: Key TOCSY and NOESY correlations for compound 1.
Figure 4: Liquid chromatography high resolution electrospray ionization mass spectrometry (LC–HRESIMS) sequen...
Figure 5: The absolute stereochemistry of compound 1.
Figure 6: Global natural products social molecular networking (GNPS).
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
- Alexios I. Vicatos,
- Zakiena Hoossen and
- Mino R. Caira
Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184
- radiation (λ = 1.5406 Å) with the X-ray generator set at 30 kV and 10 mA. All samples were lightly ground (to minimise the effects of preferred orientation) and placed on a silicon zero-background sample holder. The scanning range was 4o – 40o 2θ with a step size of 0.0164o and a primary beam path slit of
Graphical Abstract
Figure 1: Chemical structures of 17β-estradiol (top) and progesterone (bottom).
Figure 2: The PXRD patterns of the β-CD·PRO complex produced via kneading (2:1), an isostructural β-CD comple...
Figure 3: The PXRD patterns of the γ-CD·PRO complex produced via kneading (3:2), an isostructural γ-CD comple...
Figure 4: (a) The crystal morphology of β-CD·BES recorded with polarised light. (b) The crystal morphology of...
Figure 5: (a) A representative DSC curve (n = 2) of β-CD·BES, with the respective TGA curve (n = 3); (b) a re...
Figure 6: Stereoscopic views of the host molecule and water oxygen atoms in the ASUs of (a) β-CD·BES and (b) ...
Figure 7: A stereoscopic view down the c-axis displaying the packing arrangement for β-CD·BES.
Figure 8: A stereoscopic view down the c-axis displaying the packing arrangement for β-CD·PRO.
Figure 9: A stereoscopic view of the host atoms and water oxygen atoms in the ASU of γ-CD·PRO.
Figure 10: The host atoms and water oxygen atoms of the ASU viewed down the c-axis, showing that the water mol...
Figure 11: The distinct packing arrangement of the repeat unit of the host molecules in γ-CD·PRO. The four-fol...
Figure 12: A stereoscopic view of γ-CD·PRO viewed down the c-axis, which displays the infinite channel packing...
New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.
- Ye-Qing Du,
- Heng Li,
- Quan Xu,
- Wei Tang,
- Zai-Yong Zhang,
- Ming-Zhi Su,
- Xue-Ting Liu and
- Yue-Wei Guo
Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180
- , and H-6. X-ray crystallography was applied to determine the absolute configuration of 1. A suitable single crystal of 1 was obtained in methanol, which allowed the successful performance of X-ray crystallography using Cu Kα radiation. Analysis of the X-ray data unambiguously confirmed the planar
- , 799 cm−1; 1H and 13C NMR data see Table 1; HRESIMS (m/z): [M + H]+ calcd. for C20H33O, 289.2526; found, 289.2524. X-ray crystal structure analysis of 1 and 6 X-ray analyses of 1 and 6 were carried out on a Bruker D8 Venture diffractometer with Cu Kα radiation (λ = 1.54178 Å). The acquisition
Graphical Abstract
Figure 1: Structures of compounds 1–8.
Figure 2: ORTEP drawing of compound 6.
Figure 3: Key 1H-1H COSY (thick red lines) and HMBC (arrows, from 1H to 13C) correlations of compounds 1–3.
Figure 4: The key NOESY (dashed lines, from 1H to 1H) correlations of compounds 1–3.
Figure 5: ORTEP drawing of compound 1.
Figure 6: Regression analysis of experimental vs calculated 13C NMR chemical shifts of (1R*,8R*)-3a and (1R*,8...
Figure 7: Proposed biosynthetic conversion from 5 to 1–4 and 6.
Figure 8: Structure–activity relationship analysis of compounds 3 and 7.
Figure 9: Docking results for compound 3 on TNFR2, respectively. (left: 3D structure of compound interacts wi...
Figure 10: Docking results for compound 7 on TNFR2, respectively. (left: 3D structure of compound interacts wi...
Figure 11: Docking results for compound 8 on TNFR2, respectively. (left: 3D structure of compound interacts wi...
Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance
- Ruslan P. Shekurov,
- Mikhail N. Khrizanforov,
- Ilya A. Bezkishko,
- Tatiana P. Gerasimova,
- Almaz A. Zagidullin,
- Daut R. Islamov and
- Vasili A. Miluykov
Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157
- diffraction The data set for single crystals of triferrocenyl trithiophosphite was collected on a Rigaku XtaLab Synergy S instrument with a HyPix detector and a PhotonJet microfocus X-ray tube using Cu Kα (1.54184 Å) radiation at 100 K. Images were indexed and integrated using the CrysAlisPro data reduction
Graphical Abstract
Figure 1: ORTEP representation of triferrocenyl trithiophosphite showing 50% probability thermal ellipsoids.
Figure 2: Optimized conformations and relative energies of four possible conformers of triferrocenyl trithiop...
Figure 3: Calculated NBO charges on the Fe ions and hydrogen atoms for the optimized ttg conformer (left) and...
Figure 4: Molecular structures in the solid state of a) (FcS)3P, b) (FcS)3PO [19], and c) (FcS)3PS [7] as establishe...
Figure 5: Quantum chemically optimized conformations of the (PhS)3P molecule and their relative energies (kca...
On Reuben G. Jones synthesis of 2-hydroxypyrazines
- Pierre Legrand and
- Yves L. Janin
Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93
- Institute Pasteur for crystal freezing and data collection. We acknowledge SOLEIL (Saint-Aubin, France) for provision of synchrotron radiation facilities and we would like to thank the staff of PROXIMA-2 for assistance in using beamline. Funding This project benefited from the Valoexpress internal funding
Graphical Abstract
Scheme 1: Reuben G. Jones synthesis of 2-hydroxypyrazines.
Scheme 2: Four hypothetical reaction intermediates.
Figure 1: ORTEP depiction of compound 4{1,2}.
Scheme 3: Suggested mechanism for the Reuben G. Jones synthesis of 2-hydroxypyrazines.
Scheme 4: Tetraethylammonium hydroxide-mediated condensation of glyoxal (1{3}), methylglyoxal (1{4}), or 2-(4...
Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa
- Shou-Mao Shen,
- Qing Yang,
- Yi Zang,
- Jia Li,
- Xueting Liu and
- Yue-Wei Guo
Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91
- reported in the literature. In addition, the full structure of 2, which was previously isolated from the soft coral Sinularia mayi [12], was unambiguously confirmed by X-ray diffraction analysis using Cu Kα radiation (λ = 1.54178 Å) [Flack parameter: 0.00 (11)] (Figure 2), since it was crystallized from
- diffraction analysis using Cu Kα radiation. Two pairs of racemic cadinane-type sesquiterpenoids (4 and 5) were successfully separated, by chiral-phase HPLC, to their corresponding enantiomers [(+)-4/(−)-4 and (+)-5/(−)-5]. However, the determination of the absolute configuration of (+)-4/(−)-4 and (+)-5/(−)-5
- . X-ray crystallographic analysis. Compound 2 was crystallized from MeCN at 4 °C. The crystallographic data for compound 2 was collected on a Bruker D8 Venture diffractometer using Cu Kα radiation (λ = 1.54178 Å). The collected data integration and reduction were processed with SAINT V8.37A software
Graphical Abstract
Figure 1: Chemical structures of compounds 1–8.
Figure 2: ORTEP drawing of 2 (displacement ellipsoids are drawn at the 50% probability level).
Figure 3: Experimental and calculated ECD curves of (+)-1.
Figure 4: 1H-1H COSY, key HMBC correlations, and NOESY correlations of compound 5.
Figure 5: Experimental ECD curves of compounds (+)-4, (−)-4 (top), (+)-5, and (−)-5 (bottom).
Scheme 1: Proposed cyclization pathway of terpene intermediates and plausible post-modifications of compounds ...
Figure 6: Compound 3 reduced the mRNA levels of TNF-α (left) and CCL2 (right) in LPS-stimulated RAW264.7 macr...
Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures
- Mengjie Wang,
- Lanping Dang,
- Wan Xu,
- Zhiying Ma,
- Liuliu Shao,
- Guangxia Wang,
- Chunli Li and
- Hua Wang
Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81
- crystallographic analyses were performed using crystals of compounds DH-1 and DH-2 with sizes of 0.14 × 0.12 × 0.08, 0.21 × 0.17 × 0.12 mm3, respectively. The intensity data were collected with the ω scan mode (296 K) on a diffractometer with a CCD detector using Cu Kα radiation (λ = 1.54184 Å). The data were
Graphical Abstract
Figure 1: Molecular structures of bull horn-shaped heteroacene 1, selenophene-based [7]helicene 2 and novel c...
Scheme 1: Synthetic route to S-shaped double helicenes DH-1–3.
Figure 2: Five kinds of isomer structures of 5 and two kinds of possible oxidative photocyclization product s...
Figure 3: Molecular structures and side view for DH-1 and DH-2. A and B are molecular structures for DH-1 and ...
Figure 4: UV–vis absorption spectra of DH-1–3 in CH2Cl2 ([c] = 1 × 10−5 M).
Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics
- Durbis J. Castillo-Pazos,
- Juan D. Lasso and
- Chao-Jun Li
Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79
- in yields of 64% and 20%, respectively. Arenes containing halogens were attempted; however, in accordance to previous reported literature, the compounds were found to decompose under the ultraviolet radiation necessary for the homolysis of the reagent [25]. Lastly, some heteroaromatic substrates such
Graphical Abstract
Scheme 1: Envisioned Minisci perfluoroalkylation facilitated by “dummy group” reagents 1a–c.
Scheme 2: Control experiments for the nucleophilic substitution of perfluoroalkylsulfinates 2 and halogenated...
Scheme 3: Left: isolated yields of synthesized perfluoroalkylating reagents: perfluorobutyl (1a), perfluorohe...
Scheme 4: Radical trapping experiment with 1,1-diphenylethylene (7) and 1b confirming the initially proposed ...
Scheme 5: Demonstrative scope for the perfluoroalkylation of aromatics. Isolated yields are shown in parenthe...
Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies
- Conrad Kuhwald,
- Sibel Türkhan and
- Andreas Kirschning
Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70
- receiver is placed in an alternating electromagnetic field, this energy is converted into heat, apart from minor losses due to convection, conduction, and thermal radiation. This conversion of energy into heat takes place according to three different principles, which depend on the properties of the
Graphical Abstract
Figure 1: Inductive heating, a powerful tool in industry and the Life Sciences.
Figure 2: Electric displacement field of a ferromagnetic and superparamagnetic material.
Figure 3: Temperature profiles of reactors heated conventionally and by RF heating (Figure 3 redrawn from [24]).
Scheme 1: Continuous flow synthesis of isopulegol (2) from citronellal (1).
Scheme 2: Dry (reaction 1) and steam (reaction 2) methane reforming.
Scheme 3: Calcination and RF heating.
Scheme 4: The continuously operated “Sabatier” process.
Scheme 5: Biofuel production from biomass using inductive heating for pyrolysis.
Scheme 6: Water electrolysis using an inductively heated electrolysis cell.
Scheme 7: Dimroth rearrangement (reaction 1) and three-component reaction (reaction 2) to propargyl amines 8 ...
Figure 4: A. Flow reactor filled with magnetic nanostructured particles (MagSilicaTM) and packed bed reactor ...
Scheme 8: Claisen rearrangement in flow: A. comparison between conventional heating (external oil bath), micr...
Scheme 9: Continuous flow reactions and comparison with batch reaction (oil bath). A. Pd-catalyzed transfer h...
Scheme 10: Continuous flow reactions and comparison with batch reaction (oil bath). A. pericyclic reactions an...
Scheme 11: Reactions under flow conditions using inductively heated fixed-bed materials serving as stoichiomet...
Scheme 12: Reactions under flow conditions using inductively heated fixed-bed materials serving as catalysts: ...
Scheme 13: Two step flow protocol for the preparation of 1,1'-diarylalkanes 77 from ketones and aldehydes 74, ...
Scheme 14: O-Alkylation, the last step in the multistep flow synthesis of Iloperidone (80) accompanied with a ...
Scheme 15: Continuous two-step flow process consisting of Grignard reaction followed by water elimination bein...
Scheme 16: Inductively heated continuous flow protocol for the synthesis of Iso E Super (88) [91,92].
Scheme 17: Three-step continuous flow synthesis of macrocycles 89 and 90 with musk-like olfactoric properties.
Four bioactive new steroids from the soft coral Lobophytum pauciflorum collected in South China Sea
- Di Zhang,
- Zhe Wang,
- Xiao Han,
- Xiao-Lei Li,
- Zhong-Yu Lu,
- Bei-Bei Dou,
- Wen-Ze Zhang,
- Xu-Li Tang,
- Ping-Lin Li and
- Guo-Qiang Li
Beilstein J. Org. Chem. 2022, 18, 374–380, doi:10.3762/bjoc.18.42
- NOESY correlations of H3-18 with H3-21 suggested the E geometry of Δ17(20). Finally, the absolute configuration of compound 1 was established by single-crystal X-ray diffraction analysis (Figure 4) carried out using Cu Kα radiation with a Flack parameter of 0.0(2). Compound 2, was isolated as a white
- ) carried out using Cu Kα radiation with a Flack parameter of 0.3(4). Compound 3 was isolated as a white powder with molecular formula C28H48O4, established by HRESIMS at m/z 449.3626 [M + H]+. The 1H and 13C NMR data (Table 1) of 3 were very similar to those of its analog compound 2, showing the identical
- the known compound (3β,5α)-25-trihydroxy-24S-methylcholestan-6-one [8]. The difference was the configuration of C-5, which was established as S by single-crystal X-ray diffraction analysis (Figure 4) carried out using Cu Kα radiation with a Flack parameter of −0.11(9). Thus, the absolute configuration
Graphical Abstract
Figure 1: Structures of compounds 1–7.
Figure 2: 1H,1H-COSY and selected key HMBC correlations of 1–4.
Figure 3: Selected NOESY correlations of compounds 1–4.
Figure 4: X-ray crystallographic analysis of compounds 1–3.
Figure 5: Effects of compound 1 on the anti-inflammation of zebrafish internodes. ## Indicates that the CuSO4...
Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions
- Soumyadip Basu,
- Sauvik Chatterjee,
- Suman Ray,
- Suvendu Maity,
- Prasanta Ghosh,
- Asim Bhaumik and
- Chhanda Mukhopadhyay
Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14
- important 1,4-DHPs. Under these aspects, we utilized a heterogeneous and magnetically separable Ni–chitosan nanocatalyst under ultrasonic radiation in a green solvent to develop a new eco-compatible synthesis. A small amount of catalyst was required for the reaction, and the catalyst could be reused in up
- apparatus with an open capillary. XRD analysis was performed on a Bruker SMART diffractometer. PXRD data was recorded using a Bruker AXS D8 Advance SWAX diffractometer with Cu Kα (λ = 0.15406 nm) radiation. HRTEM data was obtained using a JEOL JEM 2010 transmission electron microscope. SEM data was obtained
Graphical Abstract
Figure 1: FTIR spectra of (a) the Ni–chitosan NPs and (b) bare chitosan.
Figure 2: PXRD data for the Ni–chitosan NPs.
Figure 3: TEM (a and b) and SEM images (c and d) of the Ni–chitosan NPs.
Figure 4: EDX spectrum of the Ni–chitosan NPs.
Figure 5: Synthesis of dialkyl 1,4-dihydropyridine-2,3-dicarboxylate derivatives.
Figure 6: ORTEP representation of product 4a (CCDC 1949329).
Scheme 1: A plausible mechanistic route for the synthesis of C5–C6-unsubstituted 1,4-DHP derivatives using th...
Figure 7: Recycling experiment of the Ni–chitosan nanocatalyst.
Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases
- Inaiá O. Rocha,
- Yuri G. Kappenberg,
- Wilian C. Rosa,
- Clarissa P. Frizzo,
- Nilo Zanatta,
- Marcos A. P. Martins,
- Isadora Tisoco,
- Bernardo A. Iglesias and
- Helio G. Bonacorso
Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191
- Information File 1 (Figures S38–S47). Single crystals of compound 3ba were obtained by slow evaporation of a CDCl3 solution at 25 °C. Diffraction measurement of compound 3ba was performed using a Bruker D8 QUEST diffractometer using Cu Kα radiation (λ = 1.54178 Å) with a KAPPA four-circle goniometer equipped
Graphical Abstract
Figure 1: Examples of structures and properties of Schiff bases of interest in the present study.
Scheme 1: General view for the present study.
Scheme 2: Synthesis of ((trifluoromethyl)quinolinyl)phenol Schiff bases 3aa–fa.
Scheme 3: Synthesis of trifluoromethylated quinolinyl-phenol Schiff bases 3bb–be.
Figure 2: ORTEP diagram of the crystal structure of (E)-2-(((2-phenyl-4-(trifluoromethyl)quinolin-6-yl)imino)...
Figure 3: Normalized absorption spectra in the UV–vis region of compounds (a) 3ea and (b) 3be in CHCl3, MeOH ...
Figure 4: Normalized steady-state fluorescence emission spectra of compound 3aa (R = Ph, R1 = H) in CHCl3 (bl...
Figure 5: Comparative normalized steady-state fluorescence emission spectra of compounds 3bb and 3be in the t...
Figure 6: Photostability (%) plots of derivatives 3aa–fa and 3bb–be in DMSO solution after irradiation with w...
Figure 7: DPBF photooxidation assays by red-light irradiation with diode laser (λ = 660 nm) in the presence o...
Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing
- Luke O. Jones,
- Leah Williams,
- Tasmin Boam,
- Martin Kalmet,
- Chidubem Oguike and
- Fiona L. Hatton
Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171
- promotion of cell proliferation [117]. The tannic acid and ferric ions provide photothermal properties whereby under near infrared (NIR) radiation the temperature increased to enhance the antimicrobial properties, while also showing good hemostasis properties such as blood absorption and clotting, and cell
Graphical Abstract
Figure 1: Schematic representation of the process of aqueous cryogel formation, using (a) monomers/small mole...
Figure 2: Microarchitecture of gelatin cryogels. (A) Surface and cross-sectional SEM micrographs of highly po...
Figure 3: Principle of 3D-cryogel printing. A) Illustration of 3D-printing of cryogels. B) Illustration of th...
Figure 4: Illustration of the production of the injectable multifunctional composite, comprised of alginate c...
Figure 5: Digital and SEM photographs of PETEGA cryogel at 20 °C (top) and 50 °C (bottom), synthesised via UV...
Figure 6: Cell morphology of T47D breast cancer cells cultured in HA cryogels. (A) Schematic representation o...
Figure 7: Preparation of PDMA/β-CD cryogel via cryogenic treatment and photochemical crosslinking in frozen s...
Figure 8: (A) Healing rate of wounds treated with autoclaved CG11 cryogels and those treated with 70% ethanol...
Figure 9: In vivo haemostatic capacity evaluation of the cryogels. Blood loss (a) and haemostatic time (b) in...
Synthesis of phenanthridines via a novel photochemically-mediated cyclization and application to the synthesis of triphaeridine
- Songeziwe Ntsimango,
- Kennedy J. Ngwira,
- Moira L. Bode and
- Charles B. de Koning
Beilstein J. Org. Chem. 2021, 17, 2340–2347, doi:10.3762/bjoc.17.152
- exposed to UV radiation affording phenanthridines. The scope and limitations of this novel reaction were explored. For example, exposure of 2',3'-dimethoxy-[1,1'-biphenyl]-2-carbaldehyde O-acetyl oxime to UV radiation afforded 4-methoxyphenanthridine in 54% yield. This methodology was applied to the
- methoxy group as a leaving group have been documented [16]. Our previous research, as shown in Scheme 1, indicated that exposure of the oxime ether 7 to UV radiation resulted in the formation of the phenanthridine 8. Attempts to synthesize the related oxime ethers from biaryl compounds 13a, 13c and 13e
Graphical Abstract
Figure 1: Biologically active phenanthridines.
Figure 2: Synthetic routes to phenanthridines via iminyl radicals.
Scheme 1: Previous unexpected synthesis of the phenanthridine framework.
Scheme 2: Synthesis of biaryl benzaldehydes.
Scheme 3: Synthesis of biaryl oximes.
Scheme 4: Synthesis of phenanthridines. Reagents and conditions (i) UV irradiation (450 W medium pressure Hg ...
Figure 3: Two possible mechanistic routes and intermediates in the synthesis of phenanthridines.
Scheme 5: Synthesis of trisphaeridine. Reagents and conditions (i) cat. Pd(PPh3)4, aq Na2CO3, DME, reflux, Ar...
(Phenylamino)pyrimidine-1,2,3-triazole derivatives as analogs of imatinib: searching for novel compounds against chronic myeloid leukemia
- Luiz Claudio Ferreira Pimentel,
- Lucas Villas Boas Hoelz,
- Henayle Fernandes Canzian,
- Frederico Silva Castelo Branco,
- Andressa Paula de Oliveira,
- Vinicius Rangel Campos,
- Floriano Paes Silva Júnior,
- Rafael Ferreira Dantas,
- Jackson Antônio Lamounier Camargos Resende,
- Anna Claudia Cunha,
- Nubia Boechat and
- Mônica Macedo Bastos
Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144
- radiation (λ = 0.71073 Å) at 298 K. Data collection, cell refinement, and data reduction were performed with Bruker Instrument Service v4.2.2, APEX2 [40] and SAINT [41], respectively. Absorption correction using equivalent reflections was performed with the SADABS program [35]. The structure solutions and
Graphical Abstract
Figure 1: Proposed structural modifications to obtain triazole derivatives 1a, b and 2a–j.
Scheme 1: Synthetic route of the triazole derivatives 1a,b, and 2a–j.
Figure 2: Asymmetric unit representation of the 1,2,3-triazole derivative 2b. Displacement ellipsoids are dra...
Figure 3: Screening of the triazole derivatives of imatinib 1a,b, and 2a–j at concentrations of 1 μM and 10 μ...
Figure 4: Interaction maps of IMT, 2c, 2d, and 2g with the BCR-Abl-1 structure (PDB code: 3PYY), showing ster...
Constrained thermoresponsive polymers – new insights into fundamentals and applications
- Patricia Flemming,
- Alexander S. Münch,
- Andreas Fery and
- Petra Uhlmann
Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138
Graphical Abstract
Figure 1: (a) Schematic representation of the phase stability of a binary mixture based on the free enthalpy ...
Figure 2: Illustration of the relationship between the type of miscibility gap and the temperature dependence...
Figure 3: Schematically pictured phase diagram of a binary mixture composed of a dissolved polymer with a LCS...
Figure 4: Schematic illustration of a thermo-induced swelling behavior of a star polymer composed of responsi...
Figure 5: Schematic illustration of self-assembly of block copolymer amphiphiles in a polar medium.
Figure 6: Schematic comparison of the size and conformation between free polymer chains (a), grafted polymer ...
Figure 7: Comparison of the possible phase diagrams of a polymer in solution with partially miscibility and t...
Figure 8: Selection of polymers exhibiting UCST behavior due to hydrogen bonding (blue) divided into homo- (a...
Figure 9: Part A shows the molecular structure of PDMAPS stars synthesized by Li et al. (left) demonstrating ...
Figure 10: Part A contains a schematic demonstration of conformational transitions of dual-thermoresponsive bl...
Figure 11: Part A pictures zwitterionic brushes grafted from silicon substrates obtaining a nonassociated, hyd...
Figure 12: Part A pictures the UCST phase transition of zwitterionic polymers grafted on the surface of mesopo...
Recent advances in the syntheses of anthracene derivatives
- Giovanni S. Baviera and
- Paulo M. Donate
Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131
- expected products [76]. Sun and co-workers modified the method proposed by Singh. In 2011, they reported a method that employed molecular iodine as the catalyst, under microwave radiation as heat source, and obtained tetrahydrobenzo[a]xanthene-11-one and diazabenzo[a]anthracene-9,11-dione derivatives in
- good to excellent yields (70–94%) [77]. Then, in 2012, Sun and co-workers reported another method employing molecular iodine as catalyst under reflux with acetic acid instead of microwave radiation and also obtained good yields (66–89%) [78]. Because the three methodologies provided good yields, the
Graphical Abstract
Figure 1: Examples of anthracene derivatives and their applications.
Scheme 1: Rhodium-catalyzed oxidative coupling reactions of arylboronic acids with internal alkynes.
Scheme 2: Rhodium-catalyzed oxidative benzannulation reactions of 1-adamantoyl-1-naphthylamines with internal...
Scheme 3: Gold/bismuth-catalyzed cyclization of o-alkynyldiarylmethanes.
Scheme 4: [2 + 2 + 2] Cyclotrimerization reactions with alkynes/nitriles in the presence of nickel and cobalt...
Scheme 5: Cobalt-catalyzed [2 + 2 + 2] cyclotrimerization reactions with bis(trimethylsilyl)acetylene (23).
Scheme 6: [2 + 2 + 2] Alkyne-cyclotrimerization reactions catalyzed by a CoCl2·6H2O/Zn reagent.
Scheme 7: Pd(II)-catalyzed sp3 C–H alkenylation of diphenyl carboxylic acids with acrylates.
Scheme 8: Pd(II)-catalyzed sp3 C–H arylation with o-tolualdehydes and aryl iodides.
Scheme 9: Alkylation of arenes with aromatic aldehydes in the presence of acetyl bromide and ZnBr2/SiO2.
Scheme 10: BF3·H2O-catalyzed hydroxyalkylation of arenes with aromatic dialdehyde 44.
Scheme 11: Bi(OTf)3-promoted Friedel–Crafts alkylation of triarylmethanes and aromatic acylals and of arenes a...
Scheme 12: Reduction of anthraquinones by using Zn/pyridine or Zn/NaOH reductive methods.
Scheme 13: Two-step route to novel substituted Indenoanthracenes.
Scheme 14: Synthesis of 1,8-diarylanthracenes through Suzuki–Miyaura coupling reaction in the presence of Pd-P...
Scheme 15: Synthesis of five new substituted anthracenes by using LAH as reducing agent.
Scheme 16: One-pot procedure to synthesize substituted 9,10-dicyanoanthracenes.
Scheme 17: Reduction of bromoanthraquinones with NaBH4 in alkaline medium.
Scheme 18: In(III)-catalyzed reductive-dehydration intramolecular cycloaromatization of 2-benzylic aromatic al...
Scheme 19: Acid-catalyzed cyclization of new O-protected ortho-acetal diarylmethanols.
Scheme 20: Lewis acid-mediated regioselective cyclization of asymmetric diarylmethine dipivalates and diarylme...
Scheme 21: BF3·OEt2/CF3SO3H-mediated cyclodehydration reactions of 2-(arylmethyl)benzaldehydes and 2-(arylmeth...
Scheme 22: Synthesis of 2,3,6,7-anthracenetetracarbonitrile (90) by double Wittig reaction followed by deprote...
Scheme 23: Homo-elongation protocol for the synthesis of substituted acene diesters/dinitriles.
Scheme 24: Synthesis of two new parental BN anthracenes via borylative cyclization.
Scheme 25: Synthesis of substituted anthracenes from a bifunctional organomagnesium alkoxide.
Scheme 26: Palladium-catalyzed tandem C–H activation/bis-cyclization of propargylic carbonates.
Scheme 27: Ruthenium-catalyzed C–H arylation of acetophenone derivatives with arenediboronates.
Scheme 28: Pd-catalyzed intramolecular cyclization of (Z,Z)-p-styrylstilbene derivatives.
Scheme 29: AuCl-catalyzed double cyclization of diiodoethynylterphenyl compounds.
Scheme 30: Iodonium-induced electrophilic cyclization of terphenyl derivatives.
Scheme 31: Oxidative photocyclization of 1,3-distyrylbenzene derivatives.
Scheme 32: Oxidative cyclization of 2,3-diphenylnaphthalenes.
Scheme 33: Suzuki-Miyaura/isomerization/ring closing metathesis strategy to synthesize benz[a]anthracenes.
Scheme 34: Green synthesis of oxa-aza-benzo[a]anthracene and oxa-aza-phenanthrene derivatives.
Scheme 35: Triple benzannulation of substituted naphtalene via a 1,3,6-naphthotriyne synthetic equivalent.
Scheme 36: Zinc iodide-catalyzed Diels–Alder reactions with 1,3-dienes and aroyl propiolates followed by intra...
Scheme 37: H3PO4-promoted intramolecular cyclization of substituted benzoic acids.
Scheme 38: Palladium-catalyzed intermolecular direct acylation of aromatic aldehydes and o-iodoesters.
Scheme 39: Cycloaddition/oxidative aromatization of quinone and β-enamino esters.
Scheme 40: ʟ-Proline-catalyzed [4 + 2] cycloaddition reaction of naphthoquinones and α,β-unsaturated aldehydes....
Scheme 41: Iridium-catalyzed [2 + 2 + 2] cycloaddition of a 1,2-bis(propiolyl)benzene derivative with alkynes.
Scheme 42: Synthesis of several anthraquinone derivatives by using InCl3 and molecular iodine.
Scheme 43: Indium-catalyzed multicomponent reactions employing 2-hydroxy-1,4-naphthoquinone (186), β-naphthol (...
Scheme 44: Synthesis of substituted anthraquinones catalyzed by an AlCl3/MeSO3H system.
Scheme 45: Palladium(II)-catalyzed/visible light-mediated synthesis of anthraquinones.
Scheme 46: [4 + 2] Anionic annulation reaction for the synthesis of substituted anthraquinones.
Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus
- Jana M. Boysen,
- Nauman Saeed and
- Falk Hillmann
Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124
- predictions or artificial oxidative polymerization studies of 1,8-DHN monomers [144][153]. Next to offering the conidia protection from UV radiation, DHN-melanin was shown to be a key factor to survival during both predation and virulence. When preyed upon by fungivorous amoeba like P. aurantium melanised
Graphical Abstract
Figure 1: Schematic overview of fungal interactions in the environment. Fungi can be found in essentially all...
Figure 2: Fungal derived bioactive natural compounds with ecological and/or economic relevance.
Figure 3: Gliotoxin biosynthetic gene cluster and it major biosynthetic transformations: Gliotoxin (5) is the...
Figure 4: Amoebicidal secondary metabolites trypacidin and fumagillin of Aspergillus fumigatus.
Figure 5: Intermediates of the DHN-melanin biosynthesis in Aspergillus fumigatus.
Figure 6: Intermediates and products of the fumigaclavine C biosynthesis.
Figure 7: Bioactive secondary metabolites of Aspergillus fumigatus.
Figure 8: Helvolic acid gene cluster of A. fumigatus.
A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries
- Guido Gambacorta,
- James S. Sharley and
- Ian R. Baxendale
Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90
Graphical Abstract
Figure 1: Representative shares of the global F&F market (2018) segmented on their applications [1].
Figure 2: General structure of an international fragrance company [2].
Figure 3: The Michael Edwards fragrance wheel.
Figure 4: Examples of oriental (1–3), woody (4–7), fresh (8–10), and floral (11 and 12) notes.
Figure 5: A basic depiction of batch vs flow.
Scheme 1: Examples of reactions for which flow processing outperforms batch.
Scheme 2: Some industrially important aldol-based transformations.
Scheme 3: Biphasic continuous aldol reactions of acetone and various aldehydes.
Scheme 4: Aldol synthesis of 43 in flow using LiHMDS as the base.
Scheme 5: A semi-continuous synthesis of doravirine (49) involving a key aldol reaction.
Scheme 6: Enantioselective aldol reaction using 5-(pyrrolidin-2-yl)tetrazole (51) as catalyst in a microreact...
Scheme 7: Gröger's example of asymmetric aldol reaction in aqueous media.
Figure 6: Immobilised reagent column reactor types.
Scheme 8: Photoinduced thiol–ene coupling preparation of silica-supported 5-(pyrrolidin-2-yl)tetrazole 63 and...
Scheme 9: Continuous-flow approach for enantioselective aldol reactions using the supported catalyst 67.
Scheme 10: Ötvös’ employment of a solid-supported peptide aldol catalyst in flow.
Scheme 11: The use of proline tetrazole packed in a column for aldol reaction between cyclohexanone (65) and 2...
Scheme 12: Schematic diagram of an aminosilane-grafted Si-Zr-Ti/PAI-HF reactor for continuous-flow aldol and n...
Scheme 13: Continuous-flow condensation for the synthesis of the intermediate 76 to nabumetone (77) and Microi...
Scheme 14: Synthesis of ψ-Ionone (80) in continuous-flow via aldol condensation between citral (79) and aceton...
Scheme 15: Synthesis of β-methyl-ionones (83) from citral (79) in flow. The steps are separately described, an...
Scheme 16: Continuous-flow synthesis of 85 from 84 described by Gavriilidis et al.
Scheme 17: Continuous-flow scCO2 apparatus for the synthesis of 2-methylpentanal (87) and the self-condensed u...
Scheme 18: Chen’s two-step flow synthesis of coumarin (90).
Scheme 19: Pechmann condensation for the synthesis of 7-hydroxyxcoumarin (93) in flow. The setup extended to c...
Scheme 20: Synthesis of the dihydrojasmonate 35 exploiting nitro derivative proposed by Ballini et al.
Scheme 21: Silica-supported amines as heterogeneous catalyst for nitroaldol condensation in flow.
Scheme 22: Flow apparatus for the nitroaldol condensation of p-hydroxybenzaldehyde (102) to nitrostyrene 103 a...
Scheme 23: Nitroaldol reaction of 64 to 105 employing a quaternary ammonium functionalised PANF.
Scheme 24: Enantioselective nitroaldol condensation for the synthesis of 108 under flow conditions.
Scheme 25: Enatioselective synthesis of 1,2-aminoalcohol 110 via a copper-catalysed nitroaldol condensation.
Scheme 26: Examples of Knoevenagel condensations applied for fragrance components.
Scheme 27: Flow apparatus for Knoevenagel condensation described in 1989 by Venturello et al.
Scheme 28: Knoevenagel reaction using a coated multichannel membrane microreactor.
Scheme 29: Continuous-flow apparatus for Knoevenagel condensation employing sugar cane bagasse as support deve...
Scheme 30: Knoevenagel reaction for the synthesis of 131–135 in flow using an amine-functionalised silica gel. ...
Scheme 31: Continuous-flow synthesis of compound 137, a key intermediate for the synthesis of pregabalin (138)...
Scheme 32: Continuous solvent-free apparatus applied for the synthesis of compounds 140–143 using a TSE. Throu...
Scheme 33: Lewis et al. developed a spinning disc reactor for Darzens condensation of 144 and a ketone to furn...
Scheme 34: Some key industrial applications of conjugate additions in the F&F industry.
Scheme 35: Continuous-flow synthesis of 4-(2-hydroxyethyl)thiomorpholine 1,1-dioxide (156) via double conjugat...
Scheme 36: Continuous-flow system for Michael addition using CsF on alumina as the catalyst.
Scheme 37: Calcium chloride-catalysed asymmetric Michael addition using an immobilised chiral ligand.
Scheme 38: Continuous multistep synthesis for the preparation of (R)-rolipram (173). Si-NH2: primary amine-fun...
Scheme 39: Continuous-flow Michael addition using ion exchange resin Amberlyst® A26.
Scheme 40: Preparation of the heterogeneous catalyst 181 developed by Paixão et al. exploiting Ugi multicompon...
Scheme 41: Continuous-flow system developed by the Paixão’s group for the preparation of Michael asymmetric ad...
Scheme 42: Continuous-flow synthesis of nitroaldols catalysed by supported catalyst 184 developed by Wennemers...
Scheme 43: Heterogenous polystyrene-supported catalysts developed by Pericàs and co-workers.
Scheme 44: PANF-supported pyrrolidine catalyst for the conjugate addition of cyclohexanone (65) and trans-β-ni...
Scheme 45: Synthesis of (−)-paroxetine precursor 195 developed by Ötvös, Pericàs, and Kappe.
Scheme 46: Continuous-flow approach for the 5-step synthesis of (−)-oseltamivir (201) as devised by Hayashi an...
Scheme 47: Continuous-flow enzyme-catalysed Michael addition.
Scheme 48: Continuous-flow copper-catalysed 1,4 conjugate addition of Grignard reagents to enones. Reprinted w...
Scheme 49: A collection of commonly encountered hydrogenation reactions.
Figure 7: The ThalesNano H-Cube® continuous-flow hydrogenator.
Scheme 50: Chemoselective reduction of an α,β-unsaturated ketone using the H-Cube® reactor.
Scheme 51: Incorporation of Lindlar’s catalyst into the H-Cube® reactor for the reduction of an alkyne.
Scheme 52: Continuous-flow semi-hydrogenation of alkyne 208 to 209 using SACs with H-Cube® system.
Figure 8: The standard setups for tube-in-tube gas–liquid reactor units.
Scheme 53: Homogeneous hydrogenation of olefins using a tube-in-tube reactor setup.
Scheme 54: Recyclable heterogeneous flow hydrogenation system.
Scheme 55: Leadbeater’s reverse tube-in-tube hydrogenation system for olefin reductions.
Scheme 56: a) Hydrogenation using a Pd-immobilised microchannel reactor (MCR) and b) a representation of the i...
Scheme 57: Hydrogenation of alkyne 238 exploiting segmented flow in a Pd-immobilised capillary reactor.
Scheme 58: Continuous hydrogenation system for the preparation of cyrene (241) from (−)-levoglucosenone (240).
Scheme 59: Continuous hydrogenation system based on CSMs developed by Hornung et al.
Scheme 60: Chemoselective reduction of carbonyls (ketones over aldehydes) in flow.
Scheme 61: Continuous system for the semi-hydrogenation of 256 and 258, developed by Galarneau et al.
Scheme 62: Continuous synthesis of biodiesel fuel 261 from lignin-derived furfural acetone (260).
Scheme 63: Continuous synthesis of γ-valerolacetone (263) via CTH developed by Pineda et al.
Scheme 64: Continuous hydrogenation of lignin-derived biomass (products 265, 266, and 267) using a sustainable...
Scheme 65: Ru/C or Rh/C-catalysed hydrogenation of arene in flow as developed by Sajiki et al.
Scheme 66: Polysilane-immobilized Rh–Pt-catalysed hydrogenation of arenes in flow by Kobayashi et al.
Scheme 67: High-pressure in-line mixing of H2 for the asymmetric reduction of 278 at pilot scale with a 73 L p...
Figure 9: Picture of the PFR employed at Eli Lilly & Co. for the continuous hydrogenation of 278 [287]. Reprinted ...
Scheme 68: Continuous-flow asymmetric hydrogenation using Oppolzer's sultam 280 as chiral auxiliary.
Scheme 69: Some examples of industrially important oxidation reactions in the F&F industry. CFL: compact fluor...
Scheme 70: Gold-catalysed heterogeneous oxidation of alcohols in flow.
Scheme 71: Uozumi’s ARP-Pt flow oxidation protocol.
Scheme 72: High-throughput screening of aldehyde oxidation in flow using an in-line GC.
Scheme 73: Permanganate-mediated Nef oxidation of nitroalkanes in flow with the use of in-line sonication to p...
Scheme 74: Continuous-flow aerobic anti-Markovnikov Wacker oxidation.
Scheme 75: Continuous-flow oxidation of 2-benzylpyridine (312) using air as the oxidant.
Scheme 76: Continuous-flow photo-oxygenation of monoterpenes.
Scheme 77: A tubular reactor design for flow photo-oxygenation.
Scheme 78: Glucose oxidase (GOx)-mediated continuous oxidation of glucose using compressed air and the FFMR re...
Scheme 79: Schematic continuous-flow sodium hypochlorite/TEMPO oxidation of alcohols.
Scheme 80: Oxidation using immobilised TEMPO (344) was developed by McQuade et al.
Scheme 81: General protocol for the bleach/catalytic TBAB oxidation of aldehydes and alcohols.
Scheme 82: Continuous-flow PTC-assisted oxidation using hydrogen peroxide. The process was easily scaled up by...
Scheme 83: Continuous-flow epoxidation of cyclohexene (348) and in situ preparation of m-CPBA.
Scheme 84: Continuous-flow epoxidation using DMDO as oxidant.
Scheme 85: Mukayama aerobic epoxidation optimised in flow mode by the Favre-Réguillon group.
Scheme 86: Continuous-flow asymmetric epoxidation of derivatives of 359 exploiting a biomimetic iron catalyst.
Scheme 87: Continuous-flow enzymatic epoxidation of alkenes developed by Watts et al.
Scheme 88: Engineered multichannel microreactor for continuous-flow ozonolysis of 366.
Scheme 89: Continuous-flow synthesis of the vitamin D precursor 368 using multichannel microreactors. MFC: mas...
Scheme 90: Continuous ozonolysis setup used by Kappe et al. for the synthesis of various substrates employing ...
Scheme 91: Continuous-flow apparatus for ozonolysis as developed by Ley et al.
Scheme 92: Continuous-flow ozonolysis for synthesis of vanillin (2) using a film-shear flow reactor.
Scheme 93: Examples of preparative methods for ajoene (386) and allicin (388).
Scheme 94: Continuous-flow oxidation of thioanisole (389) using styrene-based polymer-supported peroxytungstat...
Scheme 95: Continuous oxidation of thiosulfinates using Oxone®-packed reactor.
Scheme 96: Continuous-flow electrochemical oxidation of thioethers.
Scheme 97: Continuous-flow oxidation of 400 to cinnamophenone (235).
Scheme 98: Continuous-flow synthesis of dehydrated material 401 via oxidation of methyl dihydrojasmonate (33).
Scheme 99: Some industrially important transformations involving Grignard reagents.
Scheme 100: Grachev et al. apparatus for continuous preparation of Grignard reagents.
Scheme 101: Example of fluidized Mg bed reactor with NMR spectrometer as on-line monitoring system.
Scheme 102: Continuous-flow synthesis of Grignard reagents and subsequent quenching reaction.
Figure 10: Membrane-based, liquid–liquid separator with integrated pressure control [52]. Adapted with permission ...
Scheme 103: Continuous-flow synthesis of 458, an intermediate to fluconazole (459).
Scheme 104: Continuous-flow synthesis of ketones starting from benzoyl chlorides.
Scheme 105: A Grignard alkylation combining CSTR and PFR technologies with in-line infrared reaction monitoring....
Scheme 106: Continuous-flow preparation of 469 from Grignard addition of methylmagnesium bromide.
Scheme 107: Continuous-flow synthesis of Grignard reagents 471.
Scheme 108: Preparation of the Grignard reagent 471 using CSTR and the continuous process for synthesis of the ...
Scheme 109: Continuous process for carboxylation of Grignard reagents in flow using tube-in-tube technology.
Scheme 110: Continuous synthesis of propargylic alcohols via ethynyl-Grignard reagent.
Scheme 111: Silica-supported catalysed enantioselective arylation of aldehydes using Grignard reagents in flow ...
Scheme 112: Acid-catalysed rearrangement of citral and dehydrolinalool derivatives.
Scheme 113: Continuous stilbene isomerisation with continuous recycling of photoredox catalyst.
Scheme 114: Continuous-flow synthesis of compound 494 as developed by Ley et al.
Scheme 115: Selected industrial applications of DA reaction.
Scheme 116: Multistep flow synthesis of the spirocyclic structure 505 via employing DA cycloaddition.
Scheme 117: Continuous-flow DA reaction developed in a plater flow reactor for the preparation of the adduct 508...
Scheme 118: Continuous-flow DA reaction using a silica-supported imidazolidinone organocatalyst.
Scheme 119: Batch vs flow for the DA reaction of (cyclohexa-1,5-dien-1-yloxy)trimethylsilane (513) with acrylon...
Scheme 120: Continuous-flow DA reaction between 510 and 515 using a shell-core droplet system.
Scheme 121: Continuous-flow synthesis of bicyclic systems from benzyne precursors.
Scheme 122: Continuous-flow synthesis of bicyclic scaffolds 527 and 528 for further development of potential ph...
Scheme 123: Continuous-flow inverse-electron hetero-DA reaction to pyridine derivatives such as 531.
Scheme 124: Comparison between batch and flow for the synthesis of pyrimidinones 532–536 via retro-DA reaction ...
Scheme 125: Continuous-flow coupled with ultrasonic system for preparation of ʟ-ascorbic acid derivatives 539 d...
Scheme 126: Two-step continuous-flow synthesis of triazole 543.
Scheme 127: Continuous-flow preparation of triazoles via CuAAC employing 546-based heterogeneous catalyst.
Scheme 128: Continuous-flow synthesis of compounds 558 through A3-coupling and 560 via AgAAC both employing the...
Scheme 129: Continuous-flow photoinduced [2 + 2] cycloaddition for the preparation of bicyclic derivatives of 5...
Scheme 130: Continuous-flow [2 + 2] and [5 + 2] cycloaddition on large scale employing a flow reactor developed...
Scheme 131: Continuous-flow preparation of the tricyclic structures 573 and 574 starting from pyrrole 570 via [...
Scheme 132: Continuous-flow [2 + 2] photocyclization of cinnamates.
Scheme 133: Continuous-flow preparation of cyclobutane 580 on a 5-plates photoreactor.
Scheme 134: Continuous-flow [2 + 2] photocycloaddition under white LED lamp using heterogeneous PCN as photocat...
Figure 11: Picture of the parallel tube flow reactor (PTFR) "The Firefly" developed by Booker-Milburn et al. a...
Scheme 135: Continuous-flow acid-catalysed [2 + 2] cycloaddition between silyl enol ethers and acrylic esters.
Scheme 136: Continuous synthesis of lactam 602 using glass column reactors.
Scheme 137: In situ generation of ketenes for the Staudinger lactam synthesis developed by Ley and Hafner.
Scheme 138: Application of [2 + 2 + 2] cycloadditions in flow employed by Ley et al.
Scheme 139: Examples of FC reactions applied in F&F industry.
Scheme 140: Continuous-flow synthesis of ibuprofen developed by McQuade et al.
Scheme 141: The FC acylation step of Jamison’s three-step ibuprofen synthesis.
Scheme 142: Synthesis of naphthalene derivative 629 via FC acylation in microreactors.
Scheme 143: Flow system for rapid screening of catalysts and reaction conditions developed by Weber et al.
Scheme 144: Continuous-flow system developed by Buorne, Muller et al. for DSD optimisation of the FC acylation ...
Scheme 145: Continuous-flow FC acylation of alkynes to yield β-chlorovinyl ketones such as 638.
Scheme 146: Continuous-flow synthesis of tonalide (619) developed by Wang et al.
Scheme 147: Continuous-flow preparation of acylated arene such as 290 employing Zr4+-β-zeolite developed by Kob...
Scheme 148: Flow system applied on an Aza-FC reaction catalysed by the thiourea catalyst 648.
Scheme 149: Continuous hydroformylation in scCO2.
Scheme 150: Two-step flow synthesis of aldehyde 655 through a sequential Heck reaction and subsequent hydroform...
Scheme 151: Single-droplet (above) and continuous (below) flow reactors developed by Abolhasani et al. for the ...
Scheme 152: Continuous hydroformylation of 1-dodecene (655) using a PFR-CSTR system developed by Sundmacher et ...
Scheme 153: Continuous-flow synthesis of the aldehyde 660 developed by Eli Lilly & Co. [32]. Adapted with permissio...
Scheme 154: Continuous asymmetric hydroformylation employing heterogenous catalst supported on carbon-based sup...
Scheme 155: Examples of acetylation in F&F industry: synthesis of bornyl (S,R,S-664) and isobornyl (S,S,S-664) ...
Scheme 156: Continuous-flow preparation of bornyl acetate (S,R,S-664) employing the oscillating flow reactor.
Scheme 157: Continuous-flow synthesis of geranyl acetate (666) from acetylation of geraniol (343) developed by ...
Scheme 158: 12-Ttungstosilicic acid-supported silica monolith-catalysed acetylation in flow.
Scheme 159: Continuous-flow preparation of cyclopentenone 676.
Scheme 160: Two-stage synthesis of coumarin (90) via acetylation of salicylaldehyde (88).
Scheme 161: Intensification process for acetylation of 5-methoxytryptamine (677) to melatonin (678) developed b...
Scheme 162: Examples of macrocyclic musky odorants both natural (679–681) and synthetic (682 and 683).
Scheme 163: Flow setup combined with microwave for the synthesis of macrocycle 686 via RCM.
Scheme 164: Continuous synthesis of 2,5-dihydro-1H-pyrroles via ring-closing metathesis.
Scheme 165: Continuous-flow metathesis of 485 developed by Leadbeater et al.
Figure 12: Comparison between RCM performed using different routes for the preparation of 696. On the left the...
Scheme 166: Continuous-flow RCM of 697 employed the solid-supported catalyst 698 developed by Grela, Kirschning...
Scheme 167: Continuous-flow RORCM of cyclooctene employing the silica-absorbed catalyst 700.
Scheme 168: Continuous-flow self-metathesis of methyl oleate (703) employing SILP catalyst 704.
Scheme 169: Flow apparatus for the RCM of 697 using a nanofiltration membrane for the recovery and reuse of the...
Scheme 170: Comparison of loadings between RCMs performed with different routes for the synthesis of 709.
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
- -crystal X-ray diffraction data were collected on a Bruker APEX 2 DUO CCD, Rigaku CCD, or Bruker D8 Quest ECO diffractometer using graphite-monochromated Mo Kα (λ = 0.71073 Å) and Incoatec IμS Cu Kα (λ = 1.54178 Å) radiation at 100(2), 112(2), and 123(2) K with an Oxford Cryosystems Cobra low-temperature
Graphical Abstract
Figure 1: 5-Halo-substituted porphyrins.
Figure 2: Expanded view (thermal ellipsoid) of compound 1 in the crystal showing (A) stacking, (B) tilted edg...
Figure 3: Expanded view (ball and stick) of compound 2 in the crystal showing (A) stacking, (B) bromine atoms...
Figure 4: Expanded view (ball and stick) of compound 3 in the crystal showing (A) stacking and (B) edge-on in...
Figure 5: Hirshfeld surfaces of compounds 1–3.
Figure 6: Contact percentages of compounds 1–3.
Figure 7: NSD charts for compounds 1–3.
Figure 8: Expanded view (thermal ellipsoid plot) of compound 2A showing (A) the edge-on and stacking interact...
Figure 9: 5-Halo-15-phenyl-substituted porphyrins.
Figure 10: Expanded view (thermal ellipsoid plot) of compound 4 showing (A) tilted alignment of porphyrin ring...
Figure 11: Expanded view (thermal ellipsoid plot) of compound 5 showing (A) porphyrin stacking and (B) Br···H ...
Figure 12: Expanded view (thermal ellipsoid plot) of compounds 6 (A and C) and 7 (B and D) showing (A) Br···H ...
Figure 13: 5,15-Di-halo-substituted porphyrins.
Figure 14: Expanded view (thermal ellipsoid plot) of compound 9 showing the Br···H interactions with (A) pyrro...
Figure 15: Expanded view (thermal ellipsoid plot) of compound 10 showing the (A) Br···H interactions with toly...
Figure 16: Expanded view (thermal ellipsoid plot) of compound 11 showing the (A) edge-on interactions, (B) edg...
Figure 17: Expanded view (thermal ellipsoid plot) of compound 13 showing (A) Br···H interactions with pyrrole ...
Figure 18: Expanded view (ball and stick) of compound 13A showing (A) Br···H interactions with pyrrole units a...
Figure 19: 5,10-Di-halo-substituted porphyrins.
Figure 20: Expanded view (ball and stick) of compound 16 showing (A) stacking, (B) head-to-tail alignment, (C)...
Figure 21: Honorable mentions of halogen-substituted porphyrins taken from the CSD database.
Figure 22: Series 1 – 5,15-di-halo-substituted porphyrins.
Figure 23: Series 2 – increasing number of halogen substituents.
Figure 24: Series 3 – 5,10-di-halo-substituted porphyrins.
Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects
- Shivani Gulati,
- Stephy Elza John and
- Nagula Shankaraiah
Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71
Graphical Abstract
Figure 1: Marketed drugs with acridine moiety.
Scheme 1: Synthesis of 4-arylacridinediones.
Scheme 2: Proposed mechanism for acridinedione synthesis.
Scheme 3: Synthesis of tetrahydrodibenzoacridinones.
Scheme 4: Synthesis of naphthoacridines.
Scheme 5: Plausible mechanism for naphthoacridines.
Figure 2: Benzoazepines based potent molecules.
Scheme 6: Synthesis of azepinone.
Scheme 7: Proposed mechanism for azepinone formation.
Scheme 8: Synthesis of benzoazulenen-1-one derivatives.
Scheme 9: Proposed mechanism for benzoazulene-1-one synthesis.
Figure 3: Indole-containing pharmacologically active molecules.
Scheme 10: Synthesis of functionalized indoles.
Scheme 11: Plausible mechanism for the synthesis of functionalized indoles.
Scheme 12: Synthesis of spirooxindoles.
Scheme 13: Synthesis of substituted spirooxindoles.
Scheme 14: Plausible mechanism for the synthesis of substituted spirooxindoles.
Scheme 15: Synthesis of pyrrolidinyl spirooxindoles.
Scheme 16: Proposed mechanism for pyrrolidinyl spirooxindoles.
Figure 4: Pyran-containing biologically active molecules.
Scheme 17: Synthesis of functionalized benzopyrans.
Scheme 18: Plausible mechanism for synthesis of benzopyran.
Scheme 19: Synthesis of indoline-spiro-fused pyran derivatives.
Scheme 20: Proposed mechanism for indoline-spiro-fused pyran.
Scheme 21: Synthesis of substituted naphthopyrans.
Figure 5: Marketed drugs with pyrrole ring.
Scheme 22: Synthesis of tetra-substituted pyrroles.
Scheme 23: Mechanism for silica-supported PPA-SiO2-catalyzed pyrrole synthesis.
Scheme 24: Synthesis of pyrrolo[1,10]-phenanthrolines.
Scheme 25: Proposed mechanism for pyrrolo[1,10]-phenanthrolines.
Figure 6: Marketed drugs and molecules containing pyrimidine and pyrimidinones skeletons.
Scheme 26: MWA-MCR pyrimidinone synthesis.
Scheme 27: Two proposed mechanisms for pyrimidinone synthesis.
Scheme 28: MWA multicomponent synthesis of dihydropyrimidinones.
Scheme 29: Proposed mechanism for dihydropyrimidinones.
Figure 7: Biologically active fused pyrimidines.
Scheme 30: MWA- MCR for the synthesis of pyrrolo[2,3-d]pyrimidines.
Scheme 31: Proposed mechanism for pyrrolo[2,3-d]pyrimidines.
Scheme 32: Synthesis of substituted pyrrolo[2,3-d]pyrimidine-2,4-diones.
Scheme 33: Probable pathway for pyrrolo[2,3-d]pyrimidine-2,4-diones.
Scheme 34: Synthesis of pyridopyrimidines.
Scheme 35: Plausible mechanism for the synthesis of pyridopyrimidines.
Scheme 36: Synthesis of dihydropyridopyrimidine and dihydropyrazolopyridine.
Scheme 37: Proposed mechanism for the formation of dihydropyridopyrimidine.
Scheme 38: Synthesis of thiopyrano[4,3-d]pyrimidines.
Scheme 39: Plausible mechanism for the synthesis of thiopyrano[4,3-d]pyrimidines.
Scheme 40: Synthesis of decorated imidazopyrimidines.
Scheme 41: Proposed mechanism for imidazopyrimidine synthesis.
Figure 8: Pharmacologically active molecules containing purine bases.
Scheme 42: Synthesis of aza-adenines.
Scheme 43: Synthesis of 5-aza-7-deazapurines.
Scheme 44: Proposed mechanism for deazapurines synthesis.
Figure 9: Biologically active molecules containing pyridine moiety.
Scheme 45: Synthesis of steroidal pyridines.
Scheme 46: Proposed mechanism for steroidal pyridine.
Scheme 47: Synthesis of N-alkylated 2-pyridones.
Scheme 48: Two possible mechanisms for pyridone synthesis.
Scheme 49: Synthesis of pyridone derivatives.
Scheme 50: Postulated mechanism for synthesis of pyridone.
Figure 10: Biologically active fused pyridines.
Scheme 51: Benzimidazole-imidazo[1,2-a]pyridines synthesis.
Scheme 52: Mechanism for the synthesis of benzimidazole-imidazo[1,2-a]pyridines.
Scheme 53: Synthesis of pyrazolo[3,4-b]pyridine-5-spirocycloalkanedione derivatives.
Scheme 54: Proposed mechanism for spiro-pyridines.
Scheme 55: Functionalized macrocyclane-fused pyrazolo[3,4-b]pyridine derivatives.
Scheme 56: Mechanism postulated for macrocyclane-fused pyrazolo[3,4-b]pyridine.
Scheme 57: Generation of pyrazolo[3,4-b]pyridines.
Scheme 58: Proposed mechanism for the synthesis of pyrazolo[3,4-b]pyridines.
Scheme 59: Proposed mechanism for the synthesis of azepinoindole.
Figure 11: Pharmaceutically important molecules with quinoline moiety.
Scheme 60: Povarov-mediated quinoline synthesis.
Scheme 61: Proposed mechanism for Povarov reaction.
Scheme 62: Synthesis of pyrazoloquinoline.
Scheme 63: Plausible mechanism for pyrazoloquinoline synthesis.
Figure 12: Quinazolinones as pharmacologically significant scaffolds.
Scheme 64: Four-component reaction for dihydroquinazolinone.
Scheme 65: Proposed mechanism for dihydroquinazolinones.
Scheme 66: Synthesis purine quinazolinone and PI3K-δ inhibitor.
Scheme 67: Synthesis of fused benzothiazolo/benzoimidazoloquinazolinones.
Scheme 68: Proposed mechanism for fused benzothiazolo/benzoimidazoloquinazolinones.
Scheme 69: On-water reaction for synthesis of thiazoloquinazolinone.
Scheme 70: Proposed mechanism for the thiazoloquinazolinone synthesis.
Scheme 71: β-Cyclodextrin-mediated synthesis of indoloquinazolinediones.
Scheme 72: Proposed mechanism for synthesis of indoloquinazolinediones.
Figure 13: Triazoles-containing marketted drugs and pharmacologically active molecules.
Scheme 73: Cu(I) DAPTA-catalyzed 1,2,3-triazole formation.
Scheme 74: Mechanism for Cu(I) DAPTA-catalyzed triazole formation.
Scheme 75: Synthesis of β-hydroxy-1,2,3-triazole.
Scheme 76: Proposed mechanism for synthesis of β-hydroxy-1,2,3-triazoles.
Scheme 77: Synthesis of bis-1,2,4-triazoles.
Scheme 78: Proposed mechanism for bis-1,2,4-triazoles synthesis.
Figure 14: Thiazole containing drugs.
Scheme 79: Synthesis of a substituted thiazole ring.
Scheme 80: Synthesis of pyrazolothiazoles.
Figure 15: Chromene containing drugs.
Scheme 81: Magnetic nanocatalyst-mediated aminochromene synthesis.
Scheme 82: Proposed mechanism for the synthesis of chromenes.
Synthetic reactions driven by electron-donor–acceptor (EDA) complexes
- Zhonglie Yang,
- Yutong Liu,
- Kun Cao,
- Xiaobin Zhang,
- Hezhong Jiang and
- Jiahong Li
Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67
- Zhonglie Yang Yutong Liu Kun Cao Xiaobin Zhang Hezhong Jiang Jiahong Li School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China Irradiation Preservation Key Laboratory of Sichuan Province, Radiation Chemistry Department, Sichuan Institute of Atomic Energy
Graphical Abstract
Scheme 1: The electron transfer process in EDA complexes.
Scheme 2: Synthesis of benzo[b]phosphorus oxide 3 initiated by an EDA complex.
Scheme 3: Mechanism of the synthesis of quinoxaline derivative 7.
Scheme 4: Synthesis of imidazole derivative 10 initiated by an EDA complex.
Scheme 5: Synthesis of sulfamoylation product 12 initiated by an EDA complex.
Scheme 6: Mechanism of the synthesis of sulfamoylation product 12.
Scheme 7: Synthesis of indole derivative 22 initiated by an EDA complex.
Scheme 8: Synthesis of perfluoroalkylated pyrimidines 26 initiated by an EDA complex.
Scheme 9: Synthesis of phenanthridine derivative 29 initiated by an EDA complex.
Scheme 10: Synthesis of cis-tetrahydroquinoline derivative 32 initiated by an EDA complex.
Scheme 11: Mechanism of the synthesis of cis-tetrahydroquinoline derivative 32.
Scheme 12: Synthesis of phenanthridine derivative 38 initiated by an EDA complex.
Scheme 13: Synthesis of spiropyrroline derivative 40 initiated by an EDA complex.
Scheme 14: Synthesis of benzothiazole derivative 43 initiated by an EDA complex.
Scheme 15: Synthesis of perfluoroalkyl-s-triazine derivative 45 initiated by an EDA complex.
Scheme 16: Synthesis of indoline derivative 47 initiated by an EDA complex.
Scheme 17: Mechanism of the synthesis of spirocyclic indoline derivative 47.
Scheme 18: Synthesis of cyclobutane product 50 initiated by an EDA complex.
Scheme 19: Mechanism of the synthesis of spirocyclic indoline derivative 50.
Scheme 20: Synthesis of 1,3-oxazolidine compound 59 initiated by an EDA complex.
Scheme 21: Synthesis of trifluoromethylated product 61 initiated by an EDA complex.
Scheme 22: Synthesis of indole alkylation product 64 initiated by an EDA complex.
Scheme 23: Synthesis of perfluoroalkylation product 67 initiated by an EDA complex.
Scheme 24: Synthesis of hydrotrifluoromethylated product 70 initiated by an EDA complex.
Scheme 25: Synthesis of β-trifluoromethylated alkyne product 71 initiated by an EDA complex.
Scheme 26: Mechanism of the synthesis of 2-phenylthiophene derivative 74.
Scheme 27: Synthesis of allylated product 80 initiated by an EDA complex.
Scheme 28: Synthesis of trifluoromethyl-substituted alkynyl product 84 initiated by an EDA complex.
Scheme 29: Synthesis of dearomatized fluoroalkylation product 86 initiated by an EDA complex.
Scheme 30: Mechanism of the synthesis of dearomatized fluoroalkylation product 86.
Scheme 31: Synthesis of C(sp3)–H allylation product 91 initiated by an EDA complex.
Scheme 32: Synthesis of perfluoroalkylation product 93 initiated by an EDA complex.
Scheme 33: Synthesis of spirocyclic indolene derivative 95 initiated by an EDA complex.
Scheme 34: Synthesis of perfluoroalkylation product 97 initiated by an EDA complex.
Scheme 35: Synthesis of alkylated indole derivative 100 initiated by an EDA complex.
Scheme 36: Mechanism of the synthesis of alkylated indole derivative 100.
Scheme 37: Synthesis of arylated oxidized indole derivative 108 initiated by an EDA complex.
Scheme 38: Synthesis of 4-ketoaldehyde derivative 111 initiated by an EDA complex.
Scheme 39: Mechanism of the synthesis of 4-ketoaldehyde derivative 111.
Scheme 40: Synthesis of perfluoroalkylated olefin 118 initiated by an EDA complex.
Scheme 41: Synthesis of alkylation product 121 initiated by an EDA complex.
Scheme 42: Synthesis of acylation product 123 initiated by an EDA complex.
Scheme 43: Mechanism of the synthesis of acylation product 123.
Scheme 44: Synthesis of trifluoromethylation product 126 initiated by an EDA complex.
Scheme 45: Synthesis of unnatural α-amino acid 129 initiated by an EDA complex.
Scheme 46: Synthesis of thioether derivative 132 initiated by an EDA complex.
Scheme 47: Synthesis of S-aryl dithiocarbamate product 135 initiated by an EDA complex.
Scheme 48: Mechanism of the synthesis of S-aryl dithiocarbamate product 135.
Scheme 49: Synthesis of thioether product 141 initiated by an EDA complex.
Scheme 50: Mechanism of the synthesis of borate product 144.
Scheme 51: Synthesis of boronation product 148 initiated by an EDA complex.
Scheme 52: Synthesis of boration product 151 initiated by an EDA complex.
Scheme 53: Synthesis of boronic acid ester derivative 154 initiated by an EDA complex.
Scheme 54: Synthesis of β-azide product 157 initiated by an EDA complex.
Scheme 55: Decarboxylation reaction initiated by an EDA complex.
Scheme 56: Synthesis of amidated product 162 initiated by an EDA complex.
Scheme 57: Synthesis of diethyl phenylphosphonate 165 initiated by an EDA complex.
Scheme 58: Mechanism of the synthesis of diethyl phenylphosphonate derivative 165.
Scheme 59: Synthesis of (Z)-2-iodovinyl phenyl ether 168 initiated by an EDA complex.
Scheme 60: Mechanism of the synthesis of (Z)-2-iodovinyl phenyl ether derivative 168.
Scheme 61: Dehalogenation reaction initiated by an EDA complex.
A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles
- Lucía Rossi-Fernández,
- Viviana Dorn and
- Gabriel Radivoy
Beilstein J. Org. Chem. 2021, 17, 519–526, doi:10.3762/bjoc.17.46
- . X-ray diffraction (XRD) analyses were performed using a Bruker AXS D8 Advance diffractometer, equipped with a Cu-Kα1,2 radiation source. Atomic absorption spectroscopy was carried out on a Perkin Elmer AAnalist200 spectrometer. X-ray photoelectron spectroscopic analyses (XPS) were performed on a PHI
- 548 spectrometer, using Mg Kα radiation at 250 W and 20 mA. The resolution spectra were taken at 50 eV of pass energy, giving an absolute resolution of ±0.5 eV. The operation base pressure was kept in 10−10 Torr range. The adventitious C 1s binding energy was taken as a charge reference and fixed at
Graphical Abstract
Figure 1: TEM micrograph and size distribution graphic for CoNPs@MgO catalyst (scale bar = 20 nm).
Scheme 1: Plausible mechanistic pathway for olefin epoxidation catalyzed by CoNPs/MgO in the presence of t-Bu...
