Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• represents a ΔG value of −30 kJ/mol, corresponding to a Kd of approx 5 μM in the experimental conditions. (B) Manual docking of scaffold for compound 3 with selected low energy conformations of the E-isomer (yellow sticks) and Z-isomer (cyan sticks) superimposed on conserved position of galactose in all LecA

Bioinformatic prediction of the stereoselectivity of modular polyketide synthase: an update of the sequence motifs in ketoreductase domain

• Changjun Xiang,
• Shunyu Yao,
• Ruoyu Wang and
• Lihan Zhang

Beilstein J. Org. Chem. 2024, 20, 1476–1485, doi:10.3762/bjoc.20.131

• rings. The triangles indicate a product having α-substituents. (c) Crystal structure of DH-ER-KR tridomain (PDB ID 8G7W) [24]. DH, KRS, ER, KRC are colored in cyan, pink, yellow, and purple, respectively. The lid of KR catalytic pocket is colored in red. The co-crystallized cofactor is represented as

Rapid construction of tricyclic tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine via isocyanide-based multicomponent reaction

• Xiu-Yu Chen,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126

• -(2-methoxyphenyl)-2-methyl-4,4a,8,8a-tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine-3,4b,5,6,7(1H)-pentacarboxylate (4a): yellow solid, 89%, mp 209–211 °C; 1H NMR (400 MHz, CDCl3) δ 7.49 (d, J = 8.0 Hz, 1H, ArH), 7.47–7.44 (m, 3H, ArH), 7.41–7.38 (m, 1H, ArH), 7.02–6.97 (m, 1H, ArH), 6.68–6.62 (m

A comparison of structure, bonding and non-covalent interactions of aryl halide and diarylhalonium halogen-bond donors

• Nicole Javaly,
• Theresa M. McCormick and
• David R. Stuart

Beilstein J. Org. Chem. 2024, 20, 1428–1435, doi:10.3762/bjoc.20.125

• that we studied here revealed an opposite trend (Scheme 4b, orange, yellow, blue, and green dots). The halogen-bond length decreased with increasing van der Waals radii of X and the trend was more pronounced for monovalent halogen-bond donors. This is exemplified by halogen-bond complexes of the

• halogen-bond donors are clustered into hypervalent 1–8 (Scheme 6b, green dots), monovalent aryl 26–28 and 30–32 (Scheme 6b, orange dots), perfluorophenyl 33–36 (Scheme 6b, yellow dots), and imidazolium 37–40 (Scheme 6b, blue dots) linear correlations with similar slopes are observed for p-orbital

• for compounds 1–24; data from prior work is represented by grey dots [21]. Correlation of ΔG for XB bond formation and X---Cl distance for compounds 9–24 (green dots), 41–48 (orange dots), 49–52 (yellow dots), and 53–56 (blue dots). Correlation of X---Cl distance with van der Waals radii of X

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• -nanobrackets 1b. DFT-optimized structure of Cu-nanobrackets (a) 1a and (b) 1b. The yellow regions indicate their spherical cavities. (c) Experimental and calculated results of Raman spectra of 1b (λex = 488 nm). For calculation, Raman activity was transferred to Raman intensity (298.15 K, the full width at

Mechanistic investigations of polyaza[7]helicene in photoredox and energy transfer catalysis

• Johannes Rocker,
• Till J. B. Zähringer,
• Matthias Schmitz,
• Till Opatz and
• Christoph Kerzig

Beilstein J. Org. Chem. 2024, 20, 1236–1245, doi:10.3762/bjoc.20.106

• chloride. We believe that our findings pave the way for a broader usage of the inherently chiral polyazahelicene photocatalyst class, both in photoredox and energy transfer catalysis. A) Room-temperature absorption (black) and emission (yellow) spectra of Aza-H recorded in MeCN/H2O (9:1), and fluorescence

• from Ref [77], transient absorption spectrum of Aza-H with 0.3 mM MV2+ and the difference spectrum of both spectra (cyan). E) Emission lifetime of Aza-H in the presence (dark yellow) and absence (black) of 0.3 mM MV2+. Stilbene isomerization and additional energy transfer experiments. A) and B) Triplet

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• conforms to our previous experience that diaryl selenides and diaryl diselenides are frequently yellow to brownish orange solids or liquids [39][40]. These contradicting observations prompted us to reinvestigate the reaction reported by Bhat et al. in detail. Indeed, we noticed that the reaction of SeO2

• eluent. The initial pale yellow fraction was collected with 16% ethyl acetate, and the solvent was evaporated to give an off-white solid. Upon recrystallization from ethyl acetate, the above fraction afforded N1,N2-diphenyloxalamide (3) as a colorless solid. The remaining fractions were collected with 22

• , 1580, 1498, 1222, 1028, 812, 745 cm−1. N1,N2-Bis(2-methoxyphenyl)oxalamide (9): Yellow solid (4.2 mg, 0.29%); mp 220–221 °C; 1H NMR (500 MHz, CDCl3, δ) 9.96 (s, 2H), 8.42 (dd, J = 8.1, 1.7 Hz, 2H), 7.14 (td, J = 7.8, 1.6 Hz, 2H), 7.02 (td, J = 7.8, 1.4 Hz, 2H), 6.94 (dd, J = 8.2, 1.4 Hz, 2H), 3.94 (s

The Ugi4CR as effective tool to access promising anticancer isatin-based α-acetamide carboxamide oxindole hybrids

• Carolina S. Marques,
• Aday González-Bakker and
• José M. Padrón

Beilstein J. Org. Chem. 2024, 20, 1213–1220, doi:10.3762/bjoc.20.104

• ]. Carboxylic acids 2 and aldehydes/ketones 3 used in the Ugi4CR. GI50 range plot against human solid tumor cell lines of investigated α-acetamide carboxamide isatin hybrids. Green most potent, yellow intermediate, red less potent. (A) Library of isatin-based α-acetamide carboxamide oxindole derivatives

Cofactor-independent C–C bond cleavage reactions catalyzed by the AlpJ family of oxygenases in atypical angucycline biosynthesis

• Jinmin Gao,
• Liyuan Li,
• Shijie Shen,
• Guomin Ai,
• Bin Wang,
• Fang Guo,
• Tongjian Yang,
• Hui Han,
• Zhengren Xu,
• Guohui Pan and
• Keqiang Fan

Beilstein J. Org. Chem. 2024, 20, 1198–1206, doi:10.3762/bjoc.20.102

• analysis of the alp gene cluster from Streptomyces ambofaciens revealed AlpG as the homolog of JadH. The N-terminal His6-tagged construct of AlpG was expressed and purified to homogeneity in E. coli (Figure S2, Supporting Information File 1). The purified AlpG displayed a light yellow color, and the

Stability trends in carbocation intermediates stemming from germacrene A and hedycaryol

• Naziha Tarannam,
• Prashant Kumar Gupta,
• Shani Zev and
• Dan Thomas Major

Beilstein J. Org. Chem. 2024, 20, 1189–1197, doi:10.3762/bjoc.20.101

• the 6-6 bicyclic rings. Inspection of the two NCI plots in Figure 4 shows that hedycaryol F-OH has the larger isosurface with the most significant attractive region (yellow) among the two. This is supported by the fact that in F-OH, the C+···OH bond distance is the shortest (Figure 4, Table 1). It is

• to repulsive and yellow represents slightly attractive interactions. The bottom two plots are side views of the cations and emphasize the relatively puckered structure of B compared to A. NCI plots for F and H hedycaryol cations. The C+···OH distances (Å) are shown in black. Correlation plot relating

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

• conjugated π-system in which the 1,3-diphenyl substituents lie flat or nearly flat relative to the isobenzofuran backbone. Likewise, compound 2 is yellow while compounds 3 and 23 are colorless. Compounds 3 and 23 show similar absorption (λmax = 364 and 360 nm for 3 and 23, respectively) and emission (λmax

• reloaded with mesitylene (0.215 g, 1.79 mmol) and an additional 5 mL CH2Cl2. The content of the addition funnel was once again added dropwise into the round bottom flask over 5 minutes with stirring. The light-yellow solution turned to dark brown. After 15 min, 10 mL of a saturated aqueous solution of NaCl

• was added to quench the reaction. The content of the flask was transferred to a 125 mL separatory funnel and extracted twice with 20 mL of CH2Cl2. The organic extracts were combined, dried over anhydrous Na2SO4 and gravity filtered. The solvent was evaporated at reduced pressure leaving a yellow solid

Light on the sustainable preparation of aryl-cored dibromides

• Fabrizio Roncaglia,
• Alberto Ughetti,
• Nicola Porcelli,
• Biagio Anderlini,
• Andrea Severini and
• Luca Rigamonti

Beilstein J. Org. Chem. 2024, 20, 1076–1087, doi:10.3762/bjoc.20.95

• reaction mixture was kept at 5 °C instead of rt and time was extended by 15% (2 h 20 min for H2O2 dropping and 2 h after the addition). The title product was obtained as pale-yellow solid, yield: 73%. Recrystallisation from hot petroleum ether gave the pure product. White solid, 1H NMR (400 MHz, 298 K

• , CDCl3) δ 7.42 (m, 1H), 7.33 (m, 1H), 7.32 (m, 2H), 4.48 (s, 4H) ppm. 1,5-Dibromo-2,4-dimethylbenzene (2b): Brown solid, yield: 87%. Recrystallisation from hot ethanol gave the pure product as pale-yellow solid. 1H NMR (400 MHz, 298 K, CDCl3) δ 7.68 (s, 1H), 7.10 (s, 1H), 2.31 (s, 6H) ppm. 1,4-Bis

• (3b): pale orange solid, yield: quantitative. Recrystallisation from hot hexane gave the pure product as pale-yellow solid. 1H NMR (400 MHz, 298 K, CDCl3) δ 7.39 (s, 2H), 2.33 (s, 6H) ppm. 1,4-Dibromo-2,5-bis(bromomethyl)benzene (3c): From 3b: chlorobenzene (4.0 mL) was used as the solvent instead of

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

• ; found, 374.1155. Acenaphtho[1,2-b]pyrazino[2,3-e]pyrazine-9,10-dicarbonitrile (4a) An oven dried sealed tube was charged with 5,6-diaminopyrazine-2,3-dicarbonitrile (12) (0.15 g, 0.92 mmol), acenaphthylene-1,2-dione (0.15 g, 0.84 mmol) and glacial acetic acid (20 mL). The resulting pale-yellow

• suspension was heated to 115 °C for 20 hours with vigorous stirring. After 20 hours, the reaction was cooled, and yellow-gold shimmering particles began to settle out. The mixture was filtered, and the resulting gold-colored solid was recrystallized from hot DMF to obtain pure compound 4a (0.12 g, 0.39 mmol

• yellow solid of 1b was obtained (123 mg, 0.572 mmol, 91%). 1H NMR (600 MHz, DMSO-d6) δ 7.65–7.67 (dd, J = 3.6 Hz, J = 6.6 Hz, 2H), 7.84–7.86 (dd, J = 3.6 Hz, J = 6.6 Hz, 2H), 12.71 (s, 1H); 13C NMR (150 MHz, DMSO-d6) δ 126.7, 128.0, 137.4, 137.7, 155.6; HRESIMS: [M + Na]+ calcd for C10H6N4O2, 237.0388

Confirmation of the stereochemistry of spiroviolene

• Yao Kong,
• Yuanning Liu,
• Kaibiao Wang,
• Tao Wang,
• Chen Wang,
• Ben Ai,
• Hongli Jia,
• Guohui Pan,
• Min Yin and
• Zhengren Xu

Beilstein J. Org. Chem. 2024, 20, 852–858, doi:10.3762/bjoc.20.77

• 10 and 11 can be oxidized to the same 9-oxospiroviolane (12) in the same 92% isolated yield, hence confirming the structural assignment of 10 and 11. By reacting with 2,4-dinitrophenylhydrazine [34], ketone 12 was further converted to hydrazone derivative 13, which gave a brownish-yellow crystal

Methodology for awakening the potential secondary metabolic capacity in actinomycetes

• Shun Saito and
• Midori A. Arai

Beilstein J. Org. Chem. 2024, 20, 753–766, doi:10.3762/bjoc.20.69

• for maintaining the metabolic homeostasis of nutrient utilization but also for biosynthesis of antibiotics such as ACT, RED, CDA and the yellow pigment coelimycin P2 in Streptomyces coelicolor strains M145 [60][61]. Depletion of a metal component essential for growth activates the production of

SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

• Julien Borrel and
• Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

• potassium to tetrabutylammonium (7) reduced the yield to 14% (Scheme 2A). When TMS-alkyne 8 was used, no product formation occurred. In this case, we observed that the initial reaction mixture before light irradiation was colorless. This was surprising, as in all the previous experiments a yellow/orange

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Irina V. Dubonosova,
• Olga Yu. Karlutova,
• Oleg P. Demidov,
• Alexander D. Dubonosov and
• Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

• change of the solutions from yellow to dark orange. Subsequent selective interaction with AcO− led to the restoration of the initial absorption and emission properties. Thus, the obtained compounds represent dual-mode “on–off–on” switches of optical and fluorescent properties under sequential exposure to

• photoproducts 3a–c under the influence of irradiation was developed. We applied a modified procedure using a Sweko IP65 LED emitter that had been previously developed in our studies for similar tasks [30]. For this purpose, a suspension of a yellow solid 2a–c in acetonitrile was boiled for 10–15 s and then

• effect: a visually distinguishable color change of the solutions from yellow to dark orange (Figure 5). Other cations did not demonstrate a measurable effect (Figure 6). Complexes 2a–c with Fe2+ in acetonitrile and DMSO were nonfluorescent. According to spectrophotometric titration data and the isomolar

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

• Rattiya Janthanom,
• Yuta Kikuchi,
• Hiroki Kanto,
• Tomoyasu Hirose,
• Arisu Tahara,
• Takahiro Ishii,
• Arinthip Thamchaipenet and
• Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

• preparative HPLC of the crude extract, 7.9 mg of 1 was obtained (Scheme 1). Table S1 (Supporting Information File 1) shows the physicochemical properties of 1, which is a yellow oil soluble in MeOH and DMSO. The UV absorption maximum of 1 was at 286 nm (ε = 10238 M−1·cm−1). The molecular formula of 1 was

• . Advanced Marfey’s analysis A volume of 20 µL of 1 M NaHCO3 was added to each 50 µL of the hydrolysate of the de-sulfurized derivative of 1 and 1 mM standard amino acids (ʟ- and ᴅ-alanine). Then, 50 µL of ᴅ-FDLA (10 mg·mL−1 in acetone) was added to the mixtures and mixed well (the color changed from yellow

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

• ), monosodium glutamate (0.1 g/flask), and naturally sourced and filtered seawater (acquired from the Huiquan Gulf of the Yellow Sea near the campus of IOCAS, 100 mL/flask) were autoclaved at 120 °C for 20 min before inoculation. The fresh mycelia of the fungus P. boydii CS-793 were incubated in a shaker on PDB

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• of N-Boc-proline-derived TCNHPI ester 104 with q-OAc in MeCN resulted in the formation of a yellow solution, which upon blue light irradiation provided the aminodecarboxylation product 105 in 69% yield. It was hypothesized that the reaction involved the formation of EDA complex 106 that led to the

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• (Scheme 8). In addition to the spectral data confirming the composition and asymmetric structure of compound 16, a clear sign of the emerging acenaphthylene system is its yellow-orange color, which distinguishes the UV-active (yellow-green luminescence) acenaphthylene 16 from the light-beige UV-inactive

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• (9a, Figure 7) was reported by Wyman and co-workers [37]. Interestingly, compound 9a showed pronounced negative photochromism in benzene with the best E–Z conversion upon irradiation with yellow light (λirr > 520 nm), while in chloroform no photochromism was detected. The formation of the Z-isomer of

• underwent E–Z photoisomerization in benzene upon irradiation with yellow light and returned to E-isomer in darkness at room temperature within about 30 seconds [39]. One year later, Pummerer and Marondel attempted to reproduce this experiment and to detect the Z-isomer of N,N'-dimethylindigo 11a upon

• . Structures of indigo derivatives discussed in this review. Photoswitching of N,N'-diacetylindigo (9a) in CCl4 (c = 17.1 µM; cell length = 5.0 cm) irradiated with blue light (λirr = 350–510 nm): dotted line; irradiated with white light: dashed line; irradiated with yellow light (λirr > 495 nm): solid line

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• celite and washed with DCM, then, the solvent was evaporated under reduced pressure to give a crude mixture. Further purification by flash chromatography (hexane/AcOEt 1:1), gave the desired compound 5,10-dihydro-11H-dibenzo[b,e][1,4]diazepin-11-one (4a) as a yellow solid yield (0.032 g, 80%). Mp 249–251

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• further 48 hours. The reaction mixture was then concentrated and flash chromatography on silica gel (EtOAc/MeOH, 1:0→0:1) yielded a yellow syrup, which was re-dissolved in H2O (30 mL). Dowex® 50WX4 (Na+ form) resin (1.28 g) was added, and the resulting suspension was stirred at room temperature for 16

• hours. Filtration followed by concentration and lyophilisation of the filtrate yielded 2 as a pale-yellow foam (972 mg, 66%). Rf = 0.3 (EtOAc/MeOH, 3:2); [α]D +76 (c 1.0, H2O); 1H NMR (500 MHz, D2O) δ 4.95 (d, J = 3.8 Hz, 1H, H-1GalNAc), 4.62 (d, J = 7.9 Hz, 1H, H-1Gal), 4.41–4.31 (m, 4H, H-2GalNAc, H

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• black precipitate and a saturated aq solution of NaBF4 (7 mL) was added to the solution. The aqueous layer was extracted with MeNO2 (2 × 30 mL) and the combined organic layers were washed with H2O (2 × 30 mL) and dried with Na2SO4. The solvent was evaporated to give a yellow oil. The residue was

• suspended in CHCl3 (1 mL) and the remaining solid was filtered off to give the product as yellow amorphous solid (2.5 mg, 6.9 µmol, <5%); mp 164–166 °C (decomp.); 1H NMR (500 MHz, CD3CN) δ 4.07 (s, 3H, OCH3), 4.20 (s, 1H, OCH3), 7.68 (s, 1H, 7-H), 8.04 (s, 1H, 10-H), 8.10 (d, 3J = 9 Hz, 1H, 5-H), 8.31 (dd

• 45 min and the crude product was washed with n-hexane (3 mL) and recrystallized from MeOH with addition of HClO4 to give a yellow amorphous solid (29 mg, 79 µmol, 21%); mp 215–217 °C (decomp.); 1H NMR (500 MHz, CD3CN) δ 1.42 (t, 3J = 8 Hz, 3H, CH3), 3.08 (q, 3J = 8 Hz, 2H, CH2), 4.05 (s, 3H OCH3