Kinetically stabilized 1,3-diarylisobenzofurans and the possibility of preparing large, persistent isoacenofurans with unusually small HOMO–LUMO gaps

• Qian Liu and
• Glen P. Miller

Beilstein J. Org. Chem. 2024, 20, 1099–1110, doi:10.3762/bjoc.20.97

• Center using a peak-matching protocol to determine the mass and error range of the molecular ion, and employing electrospray as the ionization technique. UV–vis absorption spectra were measured with a Varian Cary 50 Scan UV–visible spectrophotometer and corrected for background signal with a solvent

Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• and DPQDs were established using gas-phase computational DFT analysis (B3LYP/6-31+G* level of theory), UV–visible spectroscopy, thermal analysis, and X-ray analysis in the solid state for 2b, 5b, and 6b. The primary takeaways from the work concern the attractive functional consequences of efficiently

A Diels–Alder probe for discovery of natural products containing furan moieties

• Alyssa S. Eggly,
• Namuunzul Otgontseren,
• Carson B. Roberts,
• Amir Y. Alwali,
• Haylie E. Hennigan and
• Elizabeth I. Parkinson

Beilstein J. Org. Chem. 2024, 20, 1001–1010, doi:10.3762/bjoc.20.88

• existing route [20] and is inexpensive ($1.80/g of starting material) to make in large quantities. It also contains a chlorine group as its MS tag, which can be easily identified via its 3:1 isotopic ratio when run on a UPLC-MS, and a phenyl ring, which allows it to be UV visible at 214 nm and 254 nm. Once

Palladium-catalyzed three-component radical-polar crossover carboamination of 1,3-dienes or allenes with diazo esters and amines

• Geng-Xin Liu,
• Xiao-Ting Jie,
• Ge-Jun Niu,
• Li-Sheng Yang,
• Xing-Lin Li,
• Jian Luo and
• Wen-Hao Hu

Beilstein J. Org. Chem. 2024, 20, 661–671, doi:10.3762/bjoc.20.59

• (PPh3)2Cl as catalyst, the model reaction also afforded the corresponding product 4a in 31% yield, demonstrating the H–Pd(II)–X species could be a possible catalytic species (Scheme 4d). According to the UV–visible spectra, the only absorbing species at 467 nm consists in the pre-catalytic system Pd(OAc

• ) Radical trapping experiments with TEMPO. b) Exclusion of possible intermediate. c) Subjecting the product Z-6i to the standard conditions. d) The control reaction with HPd(PPh3)2Cl. e) UV–visible absorption analysis. Proposed mechanisms for the carboamination of 1,3-dienes or allenes with diazo esters and

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• points were determined by an SGW X-4 micro-melting point apparatus. Optical rotations were measured in MeOH using an Optical Activity AA-55 polarimeter. UV spectra were obtained with a PuXi TU-1810 UV–visible spectrophotometer. NMR spectra data were recorded on a Bruker Avance 500 or 600 MHz spectrometer

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• stability. Conversely, selenepine 28c and selenepine Se-oxide 29c were quantitatively converted into the seco-HBC 31 by thermal activation at 200 °C for 5 min, as evidenced by UV–visible absorption and HPLC monitoring. SO-extrusion from thiepine S-oxide 29b was also successfully triggered in the solid state

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• similar to AA [12][13], indicating self-assembly via the hydrophobic effect and π-stacking interactions (Figure 3a,b). The self-assembly in water was further supported by UV–visible analysis, displaying slight red-shifts of the anthracene absorption bands relative to the spectrum in methanol (Δλmax = +3

• the self-assembly of in average six PA-CH3 amphiphiles into a small aromatic micelle (Figure 3g). In a similar way, the generation of micelles (PA-OCH3)n, (PA-OH)n, and (PA-Im)n was confirmed via NMR, UV–visible, and DLS analyses upon dissolution of the corresponding amphiphiles in water (Figure 3c,d

• H2O (2.7 mL), the suspension was sonicated with a probe sonicator (40 kHz, 150 W, 10 min), centrifuged (16,000g, 10 min), and then filtrated (200 nm pore-size membrane filter) to yield a clear brown solution containing host–guest composite (PA-OCH3)n·(C60)m. The UV–visible analysis clearly showed new

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• dichloromethane at 1 mg mL−1 concentration. Molecular absorption spectroscopy Molecular absorption spectra were recorded on Agilent Cary 100 conc UV–visible spectrophotometer between the range of 200 and 800 nm in quartz cuvettes. Stock solutions of the compounds were prepared in spectroscopic grade DMSO at 5

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• NMR spectroscopy, mass spectrometry, and elemental analysis. See Supporting Information File 1 for full synthetic and characterization details. Optical properties Using UV–visible spectroscopy, the optical properties for PDIN-FB, PDIN-B, CN-PDIN-FB, and CN-PDIN-FB in both solution and film form were

• group impacts the shape of the UV–visible film spectra, leading to ill-defined 0 → 0, 0 → 1, and 0 → 2 transitions, while those without a nitrile group exhibit well-defined 0 → 0 and 0 → 1 transitions. Complex aggregation of these compounds is evident, and no clear indication of H- or J-aggregation can

• filter. The absorbance of each saturated solution was measured with a UV–visible spectrophotometer to determine the concentration using the Beer–Lambert law and the previously determined molar extinction coefficients. PDIN-FB reached a saturated solution at a concentration at 8.4 mg/mL, PDIN-B a

Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins

• Chandra Sekhar Tekuri,
• Pargat Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2023, 19, 1216–1224, doi:10.3762/bjoc.19.89

• ) porphyrins were transformed to the corresponding free base and zinc(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrins under standard demetallation and zinc insertion conditions. The absorption and emission properties of the obtained porphyrins were investigated by using UV–visible and fluorescence

• Soret bands between 439–442 nm and four Q-bands between 526 and 642 nm (Figure 3). In contrast, UV–visible spectra of zinc(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrins 14–16 showed broadened Soret bands with slight splitting between 445–450 nm and two Q-bands at ≈566 and 606 nm (Figure 4). All the

• Varian Cary Eclipse fluorescence spectrophotometer, respectively. The mass spectra were recorded on an Agilent G 6530 AA LC-HRMS QTOF system in positive mode. Spectroscopic grade chloroform was used to measure UV–visible and emission spectra of the samples. Thin-layer chromatography (TLC) was performed

Host–guest interaction and properties of cucurbit[8]uril with chloramphenicol

• Lin Zhang,
• Jun Zheng,
• Guangyan Luo,
• Xiaoyue Li,
• Yunqian Zhang,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2021, 17, 2832–2839, doi:10.3762/bjoc.17.194

• structure stacking diagram of the CPE@Q[8] host–guest complex along the c-axis. It can be clearly seen that small hexagonal holes are formed between the complexes, which are expected to have potential applications in molecular adsorption and drug delivery. UV–visible spectroscopy The interaction between Q[8

Phenolic constituents from twigs of Aleurites fordii and their biological activities

• Kyoung Jin Park,
• Won Se Suh,
• Da Hye Yoon,
• Chung Sub Kim,
• Sun Yeou Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2021, 17, 2329–2339, doi:10.3762/bjoc.17.151

• associated with antineurodegenerative diseases. Experimental General experimental procedures. Optical rotations were measured on a JASCO P-2000 polarimeter. IR spectra were acquired with a JASCO FT/IR-4600 spectrometer. UV spectra were obtained on a Shimadzu UV-1601 UV–visible spectrophotometer. NMR spectra

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• properties. Herein, starting from readily available anthranilic acid, an efficient synthesis of 2,4-bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridine derivatives was accomplished via a one-pot double Sonogashira cross-coupling method. The UV-visible absorption and emission properties of the synthesized

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

• quadrupole time-of-flight (Q-TOF) mass spectrometer equipped with Z-spray electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) sources either in a positive or negative mode with DCTB (trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile) as the matrix. UV

• -visible absorption measurements were performed using a Shimadzu MultiSpec-1501. Synthetic procedures The synthesis of 5-bromo-10,20-diphenylporphyrin (1) [46], [5-ethynyl-10,20-diphenylporphyrinato]nickel(II) (2A) [47], 5-bromo-10,20-dihexyl-15-phenylporphyrin (5) [48], [5-bromo-10,20-dihexyl-15

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

• information Unless otherwise noted, all reagents were obtained from commercial sources and used without further purification. The UV–vis spectra were recorded on a Merertech SP-8001-6C UV–visible spectrophotometer. 1H and 13C NMR spectra were recorded on a Bruker AVANCE 500 MHz spectrometer. IR spectra were

Regioselective chemoenzymatic syntheses of ferulate conjugates as chromogenic substrates for feruloyl esterases

• Olga Gherbovet,
• Fernando Ferreira,
• Apolline Clément,
• Mélanie Ragon,
• Julien Durand,
• Sophie Bozonnet,
• Michael J. O'Donohue and
• Régis Fauré

Beilstein J. Org. Chem. 2021, 17, 325–333, doi:10.3762/bjoc.17.30

• lignocellulosic matrix. Moreover, Faes are useful tools to obtain commercially relevant ferulic acid, which represents up to 3 wt % of plant the cell wall dry weight [8]. So far, the detection and characterization of Faes has mainly relied on either the use of HPLC or on UV–visible spectrophotometry, using

• expected, the investigation of the stability of the chromogenic substrate 12 using UV–visible spectrophotometry revealed that, unlike 4-nitrocatechol-1-yl ferulate (4NTC–Fe), which undergoes spontaneous hydrolysis even at a neutral pH value and 40 °C [13], the presence of the alkyl linker procures a higher

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

• pyrrole ring, which leads to different optical absorption properties in the UV–visible range (see Figure 1). Based on the UV–vis absorption spectrum, we expect a stronger resonance enhancement for GCI than GCP at 244 nm excitation due to its higher absorbance. Again, a 244 nm excitation is necessary for

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• in the case of an excess of OA, the port interactions and inclusion interactions of OA andQ[8] can exist simultaneously. To further determine the host–guest ratio of the inclusion complex formed by Q[8] and OA, their interaction was investigated using UV–visible absorption spectroscopy via a molar

• ratio method and Job's method. Figure 3A shows the UV–visible absorption spectra of the interaction between Q[8] and OA. It can be seen that the UV absorption of OA at 275 nm and 316 nm decreased significantly as the concentration of Q[8] was increased. When n(Q[8])/n(OA) = 1, there was a clear

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

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

• Shigeyuki Yamada,
• Takuya Higashida,
• Yizhou Wang,
• Masato Morita,
• Takuya Hosokai,
• Kaveendra Maduwantha,
• Kaveenga Rasika Koswattage and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

• pathway for fluorinated benzil (2) and bisbenzil (3) derivatives. Proposed mechanism of Pd(II)-catalyzed alkyne oxidation by dimethyl sulfoxide (DMSO). Photophysical data from ultraviolet (UV)-visible absorption and steady-state photoluminescence (PL) measurementsa. Supporting Information Experimental

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

• , which exhibits a highly symmetric D2h signal pattern that consists of two singlet peaks at 8.63 and 8.25 ppm, and two doublet peaks at 8.44 and 8.32 ppm for aromatic protons. The UV–visible absorption spectrum of QB4 in toluene is shown in Figure 5. Compared with tert-butylquaterrylene in dioxane [19

Copper-catalyzed remote C–H arylation of polycyclic aromatic hydrocarbons (PAHs)

• Anping Luo,
• Min Zhang,
• Zhangyi Fu,
• Jingbo Lan,
• Di Wu and
• Jingsong You

Beilstein J. Org. Chem. 2020, 16, 530–536, doi:10.3762/bjoc.16.49

• development of diverse organic photoelectrical materials. a) UV-visible absorption spectra of 4k, 4n and 4o in toluene (1 × 10−5 mol/L). b) Emission spectra of 4k, 4n and 4o in toluene (1 × 10−5 mol/L). Direct C–H arylation of PAHs. Scope of aryliodonium salts. Reaction conditions: 1a (0.2 mmol), 2 (0.3 mmol

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• and co-worker described the synthesis of a new heteroleptic copper complex bearing a substituted bipyridine ligand (Scheme 18) [34]. The novel copper catalyst was fully characterized by X-ray crystallographic analysis, UV–visible absorption and emission as well as cyclic voltammetry. The catalyst [Cu

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

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• single−quadrupole mass spectrometer. UV–visible (UV–vis) spectra were recorded on a Hitachi U-2001 dual beam spectrophotometer. Fluorescence emission spectra were recorded in solution on a Hitachi F-7000 fluorescence spectrophotometer. Viscosity experiments were carried out using an ALPHA L Fungilab