Electro-conversion of cumene into acetophenone using boron-doped diamond electrodes

• Mana Kitano,
• Tsuyoshi Saitoh,
• Shigeru Nishiyama,
• Yasuaki Einaga and
• Takashi Yamamoto

Beilstein J. Org. Chem. 2022, 18, 1154–1158, doi:10.3762/bjoc.18.119

• ) Cyclic voltammograms of a BDD electrode in MeCN solution containing cumene (1; 5 mM) and Et4NClO4 (0.1 M). The gray dashed line shows the voltammogram in the solution without cumene. (b) Linear sweep voltammograms of BDD (red), graphite (blue), and Ni (green) electrodes in MeCN solution containing

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• reaction mechanism of 10ab synthesis, we continued to investigate four possible reaction pathways (1–4) corresponding to the green, blue, red, and black lines on the PES in different solvents, including ethanol, chloroform and dimethyl sulfoxide (DMSO) at the same level of theory. Especially, ethanol is

• from two –OH groups close together (blue line). Another competitive direction is from 4a to IS3 and finally to 10ab-v2 by the release of one H2O molecule from O–H and N–H groups. Noticeably, in the ethanol solvent model, the formation of 10ab and 10ab-v2 is thermodynamically similar (the ΔG difference

Synthesis of protected precursors of chitin oligosaccharides by electrochemical polyglycosylation of thioglycosides

• Md Azadur Rahman,
• Kana Kuroda,
• Hirofumi Endo,
• Norihiko Sasaki,
• Tomoaki Hamada,
• Hiraku Sakai and
• Toshiki Nokami

Beilstein J. Org. Chem. 2022, 18, 1133–1139, doi:10.3762/bjoc.18.117

• , we did not test a glycosylation temperature above −30 °C because of the low stability of the glycosylation intermediate at an elevated temperature [9]. It is important to note that heptasaccharide 7a, which was never obtained at −50 °C, was produced at −40 °C (in blue) and −30 °C (in black), although

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• conditions above with the addition of CYP158C1 (3 µM). Blue: the conditions above with the addition of CYP158C1 (3 µM) and RVT (0.5 mM). a) Compatible and b) incompatible substrates of CYP158C1. Products were identified using analytical method D. Proposed mechanism of CYP158C1-mediated dimerization of

Scope of tetrazolo[1,5-a]quinoxalines in CuAAC reactions for the synthesis of triazoloquinoxalines, imidazoloquinoxalines, and rhenium complexes thereof

• Laura Holzhauer,
• Chloé Liagre,
• Olaf Fuhr,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2022, 18, 1088–1099, doi:10.3762/bjoc.18.111

• different absorption properties due to the different complexation; it possesses a peak with a center at around 340 nm but no noticeable absorption in the range of 420–430 nm. The TIQ complex 30 shows two minor peaks at 332 nm and 350 nm and an intense broad peak at 386 nm, thus being blue-shifted compared

• confirmed to possess rather different properties than the triazoloquinoxaline complexes in these measurements, including a blue-shift in the absorption spectrum and anodically shifted features in cyclic voltammetry measurements. Abbreviations CuAAC, copper-catalyzed azide–alkyne cycloaddition; DIPEA, N,N

Electrochemical hydrogenation of enones using a proton-exchange membrane reactor: selectivity and utility

• Koichi Mitsudo,
• Haruka Inoue,
• Yuta Niki,
• Eisuke Sato and
• Seiji Suga

Beilstein J. Org. Chem. 2022, 18, 1055–1061, doi:10.3762/bjoc.18.107

• using a) Pd/C and b) Ir/C cathode catalyst. The yield of 2a and 3a and the recovery of 1a are shown in red, brown, and blue, respectively. Designed electrochemical hydrogenation of enones 1 with a PEM reactor. Electrochemical hydrogenation of several enones 1 with a circulating PEM reactor using a Pd/C

Synthesis, optical and electrochemical properties of (D–π)₂-type and (D–π)₂Ph-type fluorescent dyes

• Kosuke Takemura,
• Kazuki Ohira,
• Taiki Higashino,
• Keiichi Imato and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

• and OTT-2 are nearly-colorless and greenish-yellow, and show blue and green fluorescent colors, respectively. The photoabsorption spectra demonstrate that the photoabsorption maximum wavelength (λmax, abs = 424 nm) of OTT-2 occurs at a by 29 nm longer wavelength than that (λmax, abs = 395 nm) of OTK-2

• of the potential scan. (a) HOMO and (b) LUMO of OTK-2 [33] and OTT-2 derived from MO calculations (PM5, INDO/S method). The red and blue lobes denote the positive and negative signs of the coefficients of the molecular orbitals. The size of each lobe is proportional to the MO coefficient. Synthesis

New azodyrecins identified by a genome mining-directed reactivity-based screening

• Atina Rizkiya Choirunnisa,
• Kuga Arima,
• Yo Abe,
• Noritaka Kagaya,
• Kei Kudo,
• Hikaru Suenaga,
• Junko Hashimoto,
• Manabu Fujie,
• Noriyuki Satoh,
• Kazuo Shin-ya,
• Kenichi Matsuda and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2022, 18, 1017–1025, doi:10.3762/bjoc.18.102

• –G (7–10) (b). Key correlations in 2D NMR are shown. In vitro characterization of Ady1. Extracted ion chromatograms at m/z 329.3 (black) and m/z 343.3 (blue), corresponding to compound 11 and 8, respectively, are shown. Sequence similarity network of VlmA-like enzymes in the actinobacterial genomes

Efficient production of clerodane and ent-kaurane diterpenes through truncated artificial pathways in Escherichia coli

• Fang-Ru Li,
• Xiaoxu Lin,
• Qian Yang,
• Ning-Hua Tan and
• Liao-Bin Dong

Beilstein J. Org. Chem. 2022, 18, 881–888, doi:10.3762/bjoc.18.89

• chemoenzymatic strategies and biocatalysis in preparation of high value diterpenoid natural products. (a) The natural pathways (MVA: blue, MEP: green) for producing IPP and DMAPP; (b) the carbon skeletons of clerodane and kaurane diterpenes and representative bioactive natural products. acetoacetyl-CoA thiolase

• produce terpentetriene and ent-kaurene. Construction maps of single plasmid expression system and two-plasmid expression system for overproducing terpentetriene (a) and ent-kaurene (b) in E. coli. Optimizing the ratios of ISO/DMAA for overproducing terpentetriene (a) and ent-kaurene (b). Red: ISO; blue

• : DMAA; gray: ISO/DMAA 3:1 mixture. All product yields are reported as means ± SD of three replicates. (a) Terpentetriene (red) and ent-kaurene (blue) yields supplied with various concentrations of glycerol. (b) Terpentetriene (red) and ent-kaurene (blue) yields induced with different concentrations of

First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation

• Maxime Pypec,
• Laurent Jouffret,
• Claude Taillefumier and
• Olivier Roy

Beilstein J. Org. Chem. 2022, 18, 845–854, doi:10.3762/bjoc.18.85

• ); (C) overview of the hydrogen bonding network (conformation A depicted in blue, conformation B in orange), hydrogen bonds (light blue dashed lines), hanging hydrogen bonds (light green dashed lines). NOE effect interaction observed in the 2D-NOESY spectra of monomer 1 and dimer 2 in DMSO-d6

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• showed the evident red-shift upon mixing the polymer with the Lewis acid (Figure 6a). This property was also successfully demonstrated in OLEDs to modify the electroluminescence (EL) characteristics (Figure 6b). In 2020, Yang et al. designed and synthesized a blue fluorescent material CzPA-F-PD (compound

• , accompanied with a decrease of the original blue emission, as shown in Figure 7. The PL emission changed from blue to orange. This phenomenon was also reproducible by adding other Lewis acids, such as BCl3 and AlCl3. Interestingly, white light emission was achievable by adjusting the ratio of B(C6F5)3

• Lewis basic fluorescent compounds 3–14. (a) PL spectra of compound 6 in toluene after addition of 0.0 (black line), 0.1 (red line), 0.3 (green line), 0.7 (blue line), 1.3 mol equiv (orange line) B(C6F5)3. (b) EL spectra of the device with compound 6 at a constant current density of 111 mA cm−2 for 0.00

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

• DH-1 and DH-2 are shown in Table 1. The replacement of sulfur with selenium in DH-1 and DH-2 leads to turn angles in-plane and helix climbs of [5]helicene and [6]helicene of DH-1 and DH-2 significantly change (Table 1, Figure 3). Each of the two DH-1 molecules (blue and red molecules in Figure S3 of

• Supporting Information File 2) in the unit cell interacts with six adjacent molecules. For example, in Figure S3 (Supporting Information File 2), the blue molecule interacts with six adjacent molecules through multiple interactions, such as, S···S (3.44 Å), S···H (2.94 Å, 2.91 Å, 2.97 Å), H···H (2.31 Å), C

• ···C (3.31 Å), S···C (3.45 Å), and C···H (2.90 Å). Each of the two DH-2 molecules (blue and red molecules, Supporting Information File 2, Figure S7) in the unit cell interact with eight adjacent molecules through multiple interactions, such as, C···C (3.40 Å), Se···H (3.09 Å), H···H (2.26 Å), C···H

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• -dihydroxy-2-naphthoate polyprenyltransferase (blue nodes), G2: UbiA-like Ptases (red nodes), G3: (S)-2,3-di-O-geranylgeranylglyceryl phosphate synthase (purple nodes), G4: protoheme IX farnesyltransferase (green nodes), G5: 4-hydroxybenzoate octaprenyltransferase (bacterial and mitochondrial), G6

• (shown in green) and template structure (shown in blue). 8-HQA (pink) is paired to 4-HBA (green) after energy minimization. Evaluation of substrate specificity of UbiA-297. Accepted substrates are shown in red, while no product formation was observed for compounds colored in blue. HRMS signal intensities

Structural basis for endoperoxide-forming oxygenases

• Takahiro Mori and
• Ikuro Abe

Beilstein J. Org. Chem. 2022, 18, 707–721, doi:10.3762/bjoc.18.71

• -containing natural products. Structures of COXs [52][53]. (A) The overall structure of ovine COX-1. (B and C) Comparison of the cyclooxygenase sites of (B) COX-1 and (C) COX-2 in complex with AA. Yellow dashed lines show hydrogen bond interactions. The blue dashed line shows the distance between Tyr385 and

• C13 of AA. Structure of FtmOx1 [71]. (A) The FtmOx1 binary structure in complex with 2OG. (B and C) Comparison of the active site architectures between (B) the binary structure and (C) the ternary structure. Blue dashed lines show the distances between atoms and yellow dashed lines represent hydrogen

• site of NvfI in complex with asnovolin A. Blue dashed lines show the distances between atoms and yellow dashed lines represent hydrogen bond interactions. Iron atoms are depicted by orange spheres. Reactions of COXs. Proposed reaction mechanisms of COXs [24]. General reaction mechanism of Fe/2OG

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• TBTQ-CB6 to SM and the release of MV from the TBTQ-CB6MV complex. Successive amounts of SM, ranging from 0.25 to 2.00 equivalents, were quantitatively dosed into aqueous solutions of TBTQ-CB6MV (3.0 mM). As shown in Figure 5, the proton resonances associated with MV (Ha, Hb, and Hc highlighted in blue

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• achieving efficient deep-blue emission, we were interested to study the influence of substituents in position 2 of the pyrimidine ring on the TADF properties of pyrimidine–carbazole emitters. For this purpose, we performed the synthesis of novel 4,6-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)pyrimidines

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

• Saika Izumi,
• Prasannamani Govindharaj,
• Anna Drewniak,
• Paola Zimmermann Crocomo,
• Satoshi Minakata,
• Leonardo Evaristo de Sousa,
• Piotr de Silva,
• Przemyslaw Data and
• Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

• for generating the CT excited state. In comparison with the photophysical properties of the D–A–D compound, the absorption of 1 (λabs = 461 nm) is almost the same as that of POZ-DBPHZ (λabs = 463 nm) [17], while the PL emission peak appeared in a slightly blue-shifted region (λPL = 502 nm) from D–A–D

• -type compound (λPL = 521 nm for POZ-DBPHZ) in cyclohexane. These data indicate that the effective length of π-conjugation is not affected by the number of donors, probably due to the right D–A dihedral angle for both compounds in the ground state. In contrary, the slight blue-shift of the PL spectra of

• made with cyclohexane, but appear to be blue shifted with respect to measurements in toluene. Considering that cyclohexane has only a slightly lower dielectric constant (≈2.0) than toluene, it is reasonable that calculations would produce similar predictions, which makes the red-shifted experimental

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• indicating an efficient energy transfer is taking place. This was further supported by the observation, that upon loading of EsY into the m-TPEWP5G assembly, the color of the donor solution changed from sky blue to greenish-yellow under UV light. At a 2:1 donor/acceptor molar ratio, a maximum FRET efficiency

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• in Scheme 17 below the optimized reaction conditions are shown for the synthesis of compounds 62 and 64 (Scheme 17) [110]. In 2019, Sultan and co-workers described a methodology for the synthesis of quinone derivatives using a combination of potassium persulfate, trifluoroacetic acid (TFA), and blue

• -LED light [111]. Under these conditions, menadione (10) and terminal alkynes 66 underwent a [2 + 2] cycloaddition reaction generating compounds containing cyclobutene rings (67a–c), that are important precursors in natural products syntheses. It is important to note that the choice of the blue-LED

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• exhibits the lowest-energy maximum at 305 nm, which is comparable to the reported absorption spectra of known naphthyl-substituted norbornadiene derivatives [36][37]. Irradiation of 5b at 315 nm leads to a decrease of the absorption band with simultaneous formation of a blue-shifted maximum at 292 nm

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• . altamirensis DSM 44997, the bacterium was grown in minimal medium without the addition of iron salts. Initial evidence for siderophore production was obtained from a chrome azurol S (CAS) assay [9], which showed a clear color change from blue to pink upon testing of the culture broth. Several batch

Unexpected chiral vicinal tetrasubstituted diamines via borylcopper-mediated homocoupling of isatin imines

• Marco Manenti,
• Leonardo Lo Presti,
• Giorgio Molteni and
• Alessandra Silvani

Beilstein J. Org. Chem. 2022, 18, 303–308, doi:10.3762/bjoc.18.34

• also shown. Thermal ellipsoids at rt were drawn at the 50% probability level. Atoms are represented with the usual colour code (C: black; N: blue; O: red; S: yellow; H: white). Substrate scope of the borylcopper-mediated homocoupling of oxindole-based N-tert-butanesulfinyl imines 1 (isolated yields in

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• key correlations observed in the 1H-1H COSY (bold bonds), HMBC (blue) correlations of 1 (recorded in pyridine-d5, 600 MHz). The key correlations observed in the 1H-1H COSY (bold bonds), HMBC (blue), ROESY (red) of 1 (recorded in DMSO-d6, 800 MHz). 1H and 13C NMR Spectroscopic Data for 1 (δ in ppm, J

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• exhibiting solid-state fluorescence, although the fluorescence partially disappears in solution, and there is a large shift to red and blue [98][99]. Carbon–carbon bond formation The main steps in a synthesis usually involve C–C bond formation, which is usually the main reaction step, or functional group

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• space of the macrocycle. Cis and trans isomers share a fairly similar main conformation (c1, blue in the figure) with high population (31.8 and 27.9%, respectively). This conformation is stabilised by a hydrogen bond between the CO group of Ile and the NH group of Lys, and triggers the formation of a

• , analysis of the structural diversity of the two isomers of P5 indicates that P5 cis (P5.1) is more disordered (see Supporting Information File 1, Table S3), which also correlates with a blue-shifted absorption minimum compared to P5 trans (P5.2). In the partially helical structures of aAxWt (i.e., second

• is given bellow the representative structures as obtained from an average over the whole cluster (beta structures in blue, helices in green, and turn/bend in pink). C–E. Same as panel B for P5.1 (green), P5.2 (red), and P6 (blue), respectively. P5.1 and P5.2 differ in the conformation of the amide