Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups

• Neda Rafieiolhosseini,
• Matthias Killa,
• Thorben Neumann,
• Niklas Tötsch,
• Jean-Noël Grad,
• Alexander Höing,
• Thies Dirksmeyer,
• Jochen Niemeyer,
• Christian Ottmann,
• Shirley K. Knauer,
• Michael Giese,
• Jens Voskuhl and
• Daniel Hoffmann

Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137

• . AIE-active molecule 1. (a) Structure of 1 with color-coded subunits AIE, lysine, and GCP. (b) Coarse-grained bead-spring model of 1. 14-3-3ζ from (a) top and (b) side with the two monomers in red and blue. In the top view the central pore is clearly visible. The side view shows the ω shape with the

• . Sampled positions of the AIE moiety colored according to the total energy of 1 from dark red (lowest energy) to white (highest energy). The values in the color bar are in units of kJ/mol. The three columns correspond to three different perspectives (top view in left column, bottom view in central column

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• a known multiresonant TADF (MR-TADF) compound, DiKTa. The emission of the charged derivatives is red-shifted compared to the parent compound. For instance, DiKTa-OBuIm emits in the green (λPL = 499 nm, 1 wt % in mCP) while DiKTa-DPA-OBuIm emits in the red (λPL = 577 nm, 1 wt % in mCP). In 1 wt % mCP

• were prepared using both DiKTa-OBuIm and DiKTa-DPA-OBuIm as active emitters showing green (λmax = 534 nm) and red (λmax = 656 nm) emission, respectively. Keywords: electroluminescence; light-emitting electrochemical cells; multiresonance; purely organic emitters; thermally activated delayed

• TADF emitter, imCzDPS (λPL = 440 nm, ΦPL = 44%, neat film) [19]. The EL of the LEEC was red-shifted at λEL of 470 nm compared to the PL. Following these initial reports Edman and co-workers demonstrated how neutral TADF small molecules [20], polymers [21], and dendrimers [22] could be employed in LEECs

Cytochrome P450 monooxygenase-mediated tailoring of triterpenoids and steroids in plants

• Karan Malhotra and
• Jakob Franke

Beilstein J. Org. Chem. 2022, 18, 1289–1310, doi:10.3762/bjoc.18.135

• main text. Figure 1 was created with BioRender.com. This content is not subject to CC BY 4.0. Phylogenetic distribution of CYPs acting on triterpenoid and steroid scaffolds (red nodes) compared to other CYPs from higher plants [15]. Numbers and black bars mark CYP families containing CYPs known to act

Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide

• Blaine G. Fiss,
• Georgia Douglas,
• Michael Ferguson,
• Jorge Becerra,
• Jesus Valdez,
• Trong-On Do,
• Tomislav Friščić and
• Audrey Moores

Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125

• material was found to exhibit an absorption edge at ≈425 nm (Figure S5a, purple), typical for polymerized and graphitic heptazine materials [50][51]. Both phosphorus-containing structures featured broadened absorption ranges compared to g-CN, with g-h-PCN showing a red-shifted maximum at ≈572 nm (Figure

• S5a, blue) and g-h-PCN300 (Figure S5a, teal) showing a similar, also red-shifted maximum at 525 nm. Additionally, photoluminescence (PL) measurements showed an initially reduced absorption intensity for g-h-PCN (Figure S5b, blue) compared to that of g-CN (Figure S5b, purple) with further reduction

Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation

• Ashish Kumar Mazumdar,
• Gyana Prakash Nanda,
• Nisha Yadav,
• Upasana Deori,
• Upasha Acharyya,
• Bahadur Sk and
• Pachaiyappan Rajamalli

Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122

• emission spectra of BPy-pTC were red-shifted in polar media, and the emission maxima changed from λem = 476 nm in toluene to λem = 497 nm in THF and to λem = 545 nm in DCM (Figure 1c). Similarly, blue emission was observed in toluene at λem = 488 nm for BPy-p3C, and it red-shifted to λem = 530 nm in THF

• , indicated the protonation of the pyridinyl nitrogen atom (Figure S6a, Supporting Information File 1). This enhanced the electron-deficient character of the BPy acceptor core and the ground-state communication between the donor and acceptor units. As a result, the red-shifted CT absorption band in the acidic

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• solution. The color of the solution was gradually changed from deep red to dark violet, typically for the anionic complexes. The solutions obtained were ESR-silent, indicating formation of the closed-shell species. The UV–vis study showed an intensive absorption at 546 nm for 3 and at 519 nm for 4. The

• obtained for complexes 1 (black), 2 (blue), 3 (green), 4 (red) (MeCN, 0.05 M Bu4NBF4, 100 mV/s, Pt). Key correlations in the NOESY spectrum of complex (S)-4 and the corresponding characteristic fragment of the spectrum (full spectrum is given in Supporting Information File 1). Correlations in the HMBC

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

• 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

• , the reaction pathway starting from 4a through IS3 and finally yielding 10ab-v2 is a more favorable one in both thermodynamic (ΔG) and kinetic (ΔG#) aspects (red and black lines) in comparision with going through IS5 to achieve the 10ab product. For the reaction originating from 4a’, passing through

• 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

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

• dimerizes 4 to form dimers 2 and 5 in vitro (analytical method B, 254 nm). Control conditions (green): 4 (0.4 mM), NADPH (1 mM), and ferredoxin–NADP+ reductase SelFdR0978/ferredoxin SelFdx1499 (FdR/Fdx, 5 µM) in buffer (50 mM PBS, 0.2 mM DTT, 1 mM EDTA, pH 7.4) were incubated at 37 °C for 1 h. Red: the

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

• complexation of the 3-nitrogen of the triazole ring and the nitrogen of the amine side chain. The complex has a yellow color in contrast to the red complexes 27a–d. Using TIQ ligand 25b for a complexation attempt with Re(CO)5Br, an orange complex (30) was successfully isolated in 79% yield. Single crystals

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

• 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

• in the Refseq database. Nodes are colored according to the host organism’s order. Enzymes with known biosynthetic products are colored red. N2H4-detecting colorimetric assay. Proposed biosynthetic pathway of azodyrecin. 1H (500 MHz) and 13C (125 MHz) NMR data for azodyrecin D (7), azodyrecin E (8

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• ) are found downstream of the three-genes cluster (Table S1, Supporting Information File 1). Subsequently, we set out to knockout datA gene by λ-RED-mediated recombination in S. sp. KIB-H1544. Culture and fermentation results of mutant S. sp. KIB-H1544-∆datA indicated that the primary production of

• ). The deletion mutant was constructed by λ-RED-mediated PCR targeting mutagenesis method [27]. The positive cosmid pSC-21A4 was transformed into E. coli BW25113/pIJ790 for gene inactivation. Then, the PCR fragment was introduced via electro-transformation into E. coli BW25113/pIJ790-pSC-21A4, in which

Electrochemical and spectroscopic properties of twisted dibenzo[g,p]chrysene derivatives

• Tomoya Imai,
• Ryuhei Akasaka,
• Naruhiro Yoshida,
• Toru Amaya and
• Tetsuo Iwasawa

Beilstein J. Org. Chem. 2022, 18, 963–971, doi:10.3762/bjoc.18.96

• twisting results in a slight increase in the HOMO and a slight lowering of the LUMO. The twisting effect is much smaller than the conjugation effect of the MeO group. Absorption spectra of all the substituted DBC derivatives also showed a red-shift as compared to that for DBC-H. Concerning the luminescence

• . Concerning the torsion of the naphthalene moiety, the twisting caused a slight increase in the HOMO and a slight lowering of the LUMO. The twisting effect is much smaller than the conjugation effect of the MeO group. Absorption spectra of all the substituted DBC derivatives also showed a red-shift as

• mV/s and 40 mV/s for CV and SWV measurements, respectively). DFT-optimized structures, orbital drawings of HOMO, schematic drawings of orbital interaction, and energy diagrams for DBC-H, DBC-H(56°)-1, DBC-H(56°)-2, and DBC-Me. Absorption (solid line) and photoluminescence (dotted red line) spectra

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• ], whose red-shifted ICT absorption band in the solid state, compared to solution state can be explained by quadrupole–quadrupole interactions. From the onsets of the higher wavelength bands, the optical energy gap can be calculated by Equation 1 [56][57]: in which h is the Planck constant [58], c the

• speed of light [59], and λon the onset wavelength [60]. For the solution, λon was determined to be 638 nm, resulting in an optical energy gap of 1.94 eV. For the solid state, λon is shifted to higher wavelengths (701 nm), resulting in a smaller energy gap of Eg = 1.77 eV. The red shift is due to

Morita–Baylis–Hillman reaction of 3-formyl-9H-pyrido[3,4-b]indoles and fluorescence studies of the products

• Nisha Devi and
• Virender Singh

Beilstein J. Org. Chem. 2022, 18, 926–934, doi:10.3762/bjoc.18.92

• the λemission was red shifted in N-ethyl-substituted derivatives as is clearly indicated from the data presented in Table 1. CO2n-Bu and CO2t-Bu substituents enhanced the fluorescence intensity more than the other substituents (7aE, 7cE and 7eD). It is noteworthy here that in the derivatives prepared

• from the same aldehydes, a noticeable decrease in fluorescence intensity of product 8 (Morita–Baylis–Hilman + Michael adducts 8bA, 8eA and 8eB) was observed than in case of product 7 (Morita–Baylis–Hilman adducts 7bB, 7bC and 7eD) while their λemission was red-shifted in comparison to type 7 compounds

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

• 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

• IPTG. (c) Time course analysis (1–7 days) of terpentetriene (red) and ent-kaurene (blue). All product yields are reported as means ± SD of three replicates. Supporting Information Supporting Information File 158: Experimental part and supplementary figures and tables. Acknowledgements The authors

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

• of nitrogen-containing heterocycles in the fluorescent materials, the addition of a Lewis acid tended to induce red-shifted absorption and emission, shedding light on the fact that the Lewis acid interacts easily with the nitrogen-containing fluorescent materials. This interaction mechanism is the

• feasible to be bound with pyridine groups. As shown in Figure 3a, the protonation by CSA resulted in a significant red-shift in the photoluminescence (PL) spectrum, which was similar to the cases caused by other Lewis acids such as methanesulfonic acid (MSA) and dichloracetic acid (DCA). Wang et al. used

• HCl, TFA, and BBr3 as dopants which were respectively added to the donor–acceptor–donor (D–A–D) molecule 2,5-bis((N,N-diphenylamino)phenyl)thiazolothiazole (compound 2 in Figure 2) containing thiazolothiazole units. As shown in Figure 3b, four different colors ranged from green, yellow, red and NIR

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

• ···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

• Figure 4. In general, the UV–vis absorption spectra of DH-1–3 are generally similar in shape and exhibit three major absorption bands within 230–280 nm (band-I), 280–330 nm (band-II), and 304–414 nm (band-III) (Figure 4). Progressive red-shifts in the absorption spectra of band-I, band-II, and band-III

Continuous flow synthesis of azobenzenes via Baeyer–Mills reaction

• Jan H. Griwatz,
• Anne Kunz and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2022, 18, 781–787, doi:10.3762/bjoc.18.78

• . Keywords: azobenzenes; Baeyer–Mills reaction; continuous flow; molecular switches; solar fuel; Introduction Although the red-colored azobenzenes (AB) have been known for years as dyes, their applications nowadays span from energy and information storage [1][2][3][4][5], organocatalysis [6], photobiology

• . The solvent was recycled to minimize waste. After a total runtime of 3 days 72 g of AB 1t were obtained as pure red oil which corresponds to a yield of >99%. Therefore, the method should be suitable for the preparation of easily several 100 grams of azobenzene compounds. Conclusion In summary, the

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• first developed on small scale under microwave batch conditions to reach short reaction times of 1–10 min and subsequently translated to scalable flow processes [24]. While raspberries have a fruity and “berry” scent which is typically associated with the color red, the scent of citrus fruits is placed

Complementarity of solution and solid state mechanochemical reaction conditions demonstrated by 1,2-debromination of tricyclic imides

• Petar Štrbac and
• Davor Margetić

Beilstein J. Org. Chem. 2022, 18, 746–753, doi:10.3762/bjoc.18.75

• required molecules. Highly reactive dienophiles. Dibromide substrates and product 12. Scope of the Zn/Cu reaction with dibromide 10 (dienes are colored in red). Mechanochemical reaction of 10 with anthracene. Mechanochemical reaction of 11 with furan. Reactivity of bicyclo[2.2.2] dibromide 42 with dienes

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

• relationship between proteins is based on their all-against-all pairwise sequence similarities using CLANS. The E-values lower than 1.0E−6 were used to connect each sequence pair by edges. Edges color indicates pairwise identities lower than 10% in grey, 10–45% in light red, and above 45% in dark red. G1: 1,4

• -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

DDQ in mechanochemical C–N coupling reactions

• Shyamal Kanti Bera,
• Rosalin Bhanja and
• Prasenjit Mal

Beilstein J. Org. Chem. 2022, 18, 639–646, doi:10.3762/bjoc.18.64

• mechanochemical C–N coupling reactions using DDQ. The newly formed C–N bonds are shown as red lines for clarity. a) The intramolecular C(sp2)-H amidation leading to 1,2-disubstituted benzimidazoles. b) One-pot coupling to synthesize substituted quinazolin-4(3H)-ones. Scope of the mechanochemical synthesis of