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

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

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

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

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

Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

• Vladislav A. Budevich,
• Sergei V. Voitekhovich,
• Alexander V. Zuraev,
• Vadim E. Matulis,
• Vitaly E. Matulis,
• Alexander S. Lyakhov,
• Ludmila S. Ivashkevich and
• Oleg A. Ivashkevich

Beilstein J. Org. Chem. 2021, 17, 385–395, doi:10.3762/bjoc.17.34

• ) level of theory [42]. X-ray structure determination Single crystal X-ray diffraction data of the mesoionic compounds 8a, 10, 11a, and salt 9 were collected on a SMART Apex II diffractometer using graphite monochromatic Mo Kα radiation (λ = 0.71073 Å) at a temperature of 100 K. The structures were solved

Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

• Sergey V. Norkov,
• Anton V. Cherkasov,
• Andrey S. Shavyrin,
• Maxim V. Arsenyev,
• Viacheslav A. Kuropatov and
• Vladimir K. Cherkasov

Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26

• electrode (2 mm diameter), platinum wire counter electrode and Ag/AgCl/KCl reference electrode. X-ray crystallography The X-ray data for 6a–d and 7–9 were collected on Rigaku OD Xcalibur (6b–d, 7, 9) and Bruker D8 Quest (6a, 8) diffractometers (Mo Kα radiation, ω-scans technique, λ = 0.71073 Å) using APEX3

An atom-economical addition of methyl azaarenes with aromatic aldehydes via benzylic C(sp³)–H bond functionalization under solvent- and catalyst-free conditions

• Divya Rohini Yennamaneni,
• Vasu Amrutham,
• Krishna Sai Gajula,
• Rammurthy Banothu,
• Murali Boosa and
• Narender Nama

Beilstein J. Org. Chem. 2020, 16, 3093–3103, doi:10.3762/bjoc.16.259

• , variations in the absorption, an inadequate penetrating ability of the radiation into the reaction medium, and further reflection of the microwaves. Nevertheless, the solvent was water, which required long extraction processes compared to solvent-free conditions. Castro and co-workers have also reported the

UV resonance Raman spectroscopy of the supramolecular ligand guanidiniocarbonyl indole (GCI) with 244 nm laser excitation

• Tim Holtum,
• Vikas Kumar,
• Daniel Sebena,
• Jens Voskuhl and
• Sebastian Schlücker

Beilstein J. Org. Chem. 2020, 16, 2911–2919, doi:10.3762/bjoc.16.240

• form a laminar liquid column in air at the laser focus. The laser radiation was focused by two cylindrical lenses to create a line focus along the sample liquid column and a 90° scattering geometry was used for collecting the Raman scattered light. The UV–vis absorption spectra were acquired with a UV

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

• Emine Kayahan,
• Mathias Jacobs,
• Leen Braeken,
• Leen C.J. Thomassen,
• Simon Kuhn,
• Tom van Gerven and
• M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

• , quartz tubes were assembled in series and placed axially around a high-power UV lamp, as shown in Figure 3d. The reactor had an internal volume of 120 mL. The photoreactor was enclosed with an annular metal cavity that reflected UV radiation back to the reactor and served as UV protection. However, the

• photomicroreactors, which was fabricated via 3D printing [39]. Luminescent solar concentrators have been used in photovoltaic cell research for a couple of decades [40]. Noël’s group combined the use of luminescent solar concentrators with microfluidics to harvest solar radiation into a narrow wavelength region and

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

• absorption of radiation by another molecular entity called a photosensitizer. In mechanistic photochemistry, the term is limited to cases in which the photosensitizer is not consumed in the reaction” [89]. One can appreciate the close connection of this definition to that of photocatalysis, defined by the

• IUPAC as follows: “Change in the rate of a chemical reaction or its initiation under the action of ultraviolet, visible or infrared radiation in the presence of a substance – the photocatalyst – that absorbs light and is involved in the chemical transformation of the reaction partners” [90]. In

Rearrangement of o-(pivaloylaminomethyl)benzaldehydes: an experimental and computational study

• Csilla Hargitai,
• Györgyi Koványi-Lax,
• Tamás Nagy,
• Péter Ábrányi-Balogh,
• András Dancsó,
• Gábor Tóth,
• Judit Halász,
• Angéla Pandur,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2020, 16, 1636–1648, doi:10.3762/bjoc.16.136

• Spider diffractometer (Tokyo, Japan) with imaging plate area detector using graphite monochromatic Cu Kα radiation. SC-XRD structures were deposited at the Cambridge Crystallographic Data Centre under the following numbers: CCDC 1953421 (3a), 1953424 (3b), 1953422 (8b), 1953423 (23a) and 1958809 (23b

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• depth of the photon penetration and provide more charge separation events. Upconversion photocatalysis is an emerging field of research that utilises near-infrared (NIR) radiation to penetrate deep into a reaction medium or material [50]. Multiple NIR photons are then combined through energy transfer

• been utilised for hydrogen production but using high intensity, short-wave UV radiation, and only a modest efficiency was obtained [122]. As a result, research into g-C3N4 grew exponentially and paved the way for the development of many other organic materials for photocatalysis applications [120][123

• , irreversible affinity for the catalyst to the support surface, (ii) stability towards the reaction conditions and reactive photogenerated intermediates, (iii) transparency to the wavelengths of radiation used to excite the catalyst, and preferably elastic scattering of the incident light, (iv) a high surface

One-step route to tricyclic fused 1,2,3,4-tetrahydroisoquinoline systems via the Castagnoli–Cushman protocol

• Aleksandar Pashev,
• Nikola Burdzhiev and
• Elena Stanoeva

Beilstein J. Org. Chem. 2020, 16, 1456–1464, doi:10.3762/bjoc.16.121

• were collected at 300 K the by v-scan technique, on a Mitigen Micromount and automatically centered on a Bruker SMART X2S Benchtop Crystallographic system. Intensity measurements were performed using monochromatized Mo Kα radiation (λ = 0.71073 Å) from a sealed microfocus tube and BREEZE CCD detector

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• ]. Microwave irradiation is a promising alternative with some advantages. In contrast to conventional heating, which is based on the convection mechanism involving conduction and radiation, the sample can be heated uniformly and contactless by the heat generated from electromagnetic energy, resulting in

• heating of microwave radiation [18]. Lin and co-workers compared the activated carbon preparation with KOH activation by conventional and microwave heating. The microwave-induced materials showed higher surface areas compared to those prepared by conventional heating using the same precursor to activating

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

• Esteban P. Urriolabeitia,
• Pablo Sánchez,
• Alexandra Pop,
• Cristian Silvestru,
• Eduardo Laga,
• Ana I. Jiménez and
• Carlos Cativiela

Beilstein J. Org. Chem. 2020, 16, 1111–1123, doi:10.3762/bjoc.16.98

• Bruker D8 Venture (4a) diffractometers, using graphite monochromated Mo Kα radiation (λ = 0.71073 Å). A hemisphere of data was collected in each case based on ω-scan or φ-scan runs. The diffraction frames were integrated using the program SAINT [67] and the integrated intensities were corrected for

Towards triptycene functionalization and triptycene-linked porphyrin arrays

• Gemma M. Locke,
• Keith J. Flanagan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

• collected on a Bruker APEX 2 DUO CCD diffractometer by using graphite-monochromated Mo Kα (λ = 0.71073 Å) radiation. Crystals were mounted on a MiTeGen MicroMount and collected at 100(2) K by using an Oxford Cryosystems Cobra low-temperature device. Data were collected by using omega and phi scans and were

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

• Marcin Kaźmierczak and
• Henryk Koroniak

Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69

• for 14c were collected at 100(1) K by the ω-scan technique on Rigaku four-circle Xcalibur diffractometer (Eos detector) with graphite-monochromatized Mo Kα radiation (λ = 0.71073 Å). The data were corrected for Lorentz-polarization and absorption effects [46]. Accurate unit cell parameters were

Synthesis of C₇₀-fragment buckybowls bearing alkoxy substituents

• Yumi Yakiyama,
• Shota Hishikawa and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2020, 16, 681–690, doi:10.3762/bjoc.16.66

• the detector at 150 K in house. The diffraction images processsing and absorption correction were performed by using RIGAKU RAPID AUTO [28]. The diffraction data for 5b was recorded on an ADSC Q210 CCD area detector with a synchrotron radiation (λ = 0.70000 Å) at 2D beamline in Pohang Accelerator

• for Scientific Research on Innovative Area “π Space Figuration” from MEXT (No. JP26102002), and JSPS KAKENHI (19H00912). The X-ray diffraction study of 5b with synchrotron radiation was performed at the Pohang Accelerator Laboratory (Beamline 2D) supported by POSTECH.

Direct borylation of terrylene and quaterrylene

• Haruka Kano,
• Keiji Uehara,
• Kyohei Matsuo,
• Hironobu Hayashi,
• Hiroko Yamada and
• Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

• -time-of-flight (MALDI–TOF) method on a JEOL SpiralTOF/JMS-S3000 spectrometer. X-ray crystallographic data were recorded at 103 K with a BRUKER-APEXII X-ray diffractometer using Mo Kα radiation equipped with a large area CCD detector. UV–vis absorption spectra were measured with a JASCO UV/Vis/NIR

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

• less as aforementioned molecular ovens. Recently development of light sources in the NIR based on LEDs brought new hope in this field [65]. Furthermore, the fact that still some fluorescence occurs makes them interesting as fluorescent probes for imaging applications. NIR radiation possesses a

• scattering coefficient being a third with respect to those measured at 400 nm [82]. Particularly, biological materials have received increased interest since they benefit from deeper penetration of radiation into the sample. Absorbers with an absorption maximum >900 nm (compare 2–11) exhibit fluorescence

Six-fold C–H borylation of hexa-peri-hexabenzocoronene

• Mai Nagase,
• Kenta Kato,
• Akiko Yagi,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2020, 16, 391–397, doi:10.3762/bjoc.16.37

• rotating anode (Graphite-monochromated Mo Kα radiation (λ = 0.71073 Å)) and PILATUS200K hybrid photon-counting detector. Cell parameters were determined and refined, and raw frame data were integrated using CrysAlisPro (Agilent Technologies, 2010). The structures were solved by direct methods with (SHELXT

Absolute configurations of talaromycones A and B, α-diversonolic ester, and aspergillusone B from endophytic Talaromyces sp. ECN211

• Ken-ichi Nakashima,
• Junko Tomida,
• Takao Hirai,
• Yoshiaki Kawamura and
• Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 290–296, doi:10.3762/bjoc.16.28

• carbonyl group at the C-7 position. However, the complete structure of 1 could not be determined by NMR spectroscopy due to a lack of HMBC correlations between the partial structures. Therefore, we crystalized 1 by vapor diffusion with benzene/n-hexane. Single-crystal X-ray diffraction using Cu radiation

• -ray diffractometry using Cu radiation revealed the absolute configuration of 5 to be 4S,5R,6R,7E,10aR by the Flack parameter (−0.13(16), Figure 5a). We also acquired the ECD spectrum of (4S,5R,6R,7E,10aR)-glauconic acid (Figure 5b). Glauconic acid (5) had been originally isolated by Barton et al. in

• diffractometers using Cu Kα radiation. DNA sequencing was performed with an Applied Biosystems 3130 genetic analyzer. Silica gel AP-300 (Toyota Kako) and Cosmosil 75C 18-OPN (Nacalai Tesque) were used for column chromatography. Silica gel 60 F254 and RP-18 F254S (both Merck) were used for TLC. Fungal material The

Halogen-bonding-induced diverse aggregation of 4,5-diiodo-1,2,3-triazolium salts with different anions

• Xingyu Xu,
• Shiqing Huang,
• Zengyu Zhang,
• Lei Cao and
• Xiaoyu Yan

Beilstein J. Org. Chem. 2020, 16, 78–87, doi:10.3762/bjoc.16.10

• , 2-Br and 2-Cl were collected at 200 K using an IμS micro-focus sealed X-ray tube with Mo Kα radiation (λ = 0.71073 Å) on a Bruker D8 venture Kappa Duo diffractometer equipped with a PHOTON 100 detector. Low-temperature holding was achieved by a Cryostream Cooler (Oxford Cryosystems). Single crystal

Carbazole-functionalized hyper-cross-linked polymers for CO₂ uptake based on Friedel–Crafts polymerization on 9-phenylcarbazole

• Dandan Fang,
• Xiaodong Li,
• Meishuai Zou,
• Xiaoyan Guo and
• Aijuan Zhang

Beilstein J. Org. Chem. 2019, 15, 2856–2863, doi:10.3762/bjoc.15.279

• NETZSCH TG 209F1 TG analyzer for 40–800 °C at a heating rate of 10 °C min−1 under a nitrogen flow of 50 mL min−1. The X-ray diffraction (XRD) patterns of the as prepared polymers were collected using a PANalytical X’pert Pro MPD diffractometer with Cu Kα radiation at room temperature, with step size of