Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• associated with this absorption centered at 615 nm possess a low molar extinction coefficient (ε ≈ 220 cm−1 M−1, inset in Figure 3). Infrared (IR) spectroscopy was performed via attenuated total reflectance (ATR) and showed the characteristic stretching vibration of the NCS groups at 2069 cm−1 (Figure S3 in

• removed under reduced pressure and the crude product was washed with cold MeOH and Et2O, obtaining a lilac precipitate (82 mg, 0.11 mmol, 60%). Paramagnetic properties were estimated by the Evans method [56] in acetonitrile and resulted in three unpaired electrons. ATR–IR (cm−1) ν: 3109, 3027, 2065, 1606

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• given in Table 1. Raman spectra of both compounds were acquired off-resonance (Figure 1). Compound 1 presents the main peak at 1609 cm−1 assigned to C=C stretching from the chromophore, a peak of intermediate intensity at 1292 cm−1 assigned to C–H bending and ring stretching, and a less intense peak at

• 1712 cm−1 which corresponds to C=O stretching [27]. The pair at 1390 and 1417 cm−1 is attributed to perylene ring stretching [28]. As observed for bis(phenethylimido)perylene (PhPTCD) [29] only a small number of peaks is observed. In contrast, compound 2 presents a larger number of peaks, with the

• spectrum being dominated by the peak at 1338 cm−1 (C–N stretching). The peak at 1272 (C–H bending and ring stretching), and the pair of peaks at 1586 and 1624 cm−1 are assigned to the C=C stretching mode [30]. Less intense peaks can be observed at 1186 (C–H bending), 1512 (perylene ring stretching), and

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• heating rate) [lit [40] mp 269–270 °C (MeOH)]; IR (KBr, cm−1) ν: 3423 (br s), 3365 (s), 3307 (br s), 3182 (br s), 1626 (sh), 1596 (vs), 1555 (s), 1547 (sh), 1242 (s), 1164 (s), 965 (s); 1H NMR (600.13 MHz, DMSO-d6) δ 11.82 (d, 3J = 11.2 Hz, 2Н, two NH), 8.01 (q, 4J = 0.5 Hz, 2Н, H-3 and H-11), 7.47 (d, 3J

• white solid which was used in the next step. IR (KBr, cm–1) ν: 3294 (m), 3251 (s), 3157 (m), 3130 (s), 1662 (vs), 1583 (s), 1552 (m), 1228 (s), 1155 (m), 961 (s), 853 (s), 764 (s); 1H NMR (600.13 MHz, DMSO-d6) δ 8.25 (unresolved q, 1Н, H-3), 7.87 (s, 1Н, H-6), 7.61 (very br s, 1H, C=NH), 5.40 (br s, 2Н

• , washed with ice-cold H2O, and dried to give compound 10 (0.104 g, 28%) as a light pink solid. Mp 204.5–206 °C (water); IR (KBr, cm–1) ν: 3414 (br vs), 3315 (br vs), 3200 (br s), 3143 (s), 3094 (s), 1721 (w), 1647 (w), 1605 (vs), 1538 (s), 1517 (s), 1407 (s), 1216 (m), 1131 (s), 962 (s), 860 (s), 738 (s

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

• – and B3LYP/6-311G(d,p)/IEFPCM – water – for hdz-CH3 and hdz-NO2 and fitted very well with the respective experimental data, especially in the lower-frequencies region, i.e., below 2000 cm−1 (Figure 4 and Tables S3 and S4 in Supporting Information File 1). It is worth noting that the assignments of

• modes, theoretical results indicate that the frequency in hdz-CH3 (3407 cm−1) is higher than that in hdz-NO2 (3326 cm−1), suggesting a lower bond force constant in the latter. Differences were observed in the hydroxy bending vibrations as well, and those were perfectly observable in the spectra: δip(C–O

• –H) and δoop(O–H) modes were assigned, respectively, at 1376 and 720 cm−1 for hdz-CH3, and at 1359 and 747 cm−1 for hdz-NO2. Interestingly, DFT showed that, while these vibrations are “clean” in hdz-CH3, they were coupled with NBA ring movements in hdz-NO2. Therefore, the IR results confirm the

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• intramolecular charge-transfer (ICT) transition from carbazole donor to Nz acceptor, respectively. Such weak ICT absorption peak (ε = 17,000 M−1 cm−1) as compared to the π–π* absorption peak (ε = 95,300 M−1 cm−1) symbolizes a weak electronic coupling between the carbazole donor and the Nz acceptor parts because

• explained as the Poole–Frenkel effect obeying the relationship, log µ ∝ E1/2 [59]. The measured mobilities of the holes (μh) and electrons (μe) of TPECNz thin film at 950 (V cm−1)1/2 electric field were 4.42 × 10−6 and 1.50 × 10−5 cm2 V−1 s−1, respectively. This result suggested that TPECNz was an ambipolar

• substrate with a sheet resistance of 12 Ω sq−1 was pre-cleaned carefully and cured with UV/O3 for 20 min. The OLED with an active diode area of 0.04 cm−2 was fabricated using a Kurt J. Lasker mini SPECTROS 100 thin film deposition system under vacuum conditions with a base pressure lower than 1 × 10−5 bar

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

• (see Supporting Information File 1, Figures S18–S25), where PDIN-FB has the highest ε at 85,238 M−1 cm−1, CN-PDIN-FB the second highest ε at 78,119 M−1 cm−1, PDIN-B the third highest ε at 74,489 M−1 cm−1, and CN-PDIN-B the lowest ε at 59,485 M−1 cm−1. In terms of film spectra, all four materials were

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• formula of C45H64O28SNa (calcd 1107.3197). The IR spectrum showed absorption peaks corresponding to hydroxy groups (νmax = 3414 cm−1) and carbonyl groups (νmax = 1782 and 1695 cm−1). The 1H NMR signals (Table 1) were characteristic of a breynogenin moiety, namely, a methyl group [δH 0.92 (d, J = 6.9 Hz

• compound 4 (1.2 mg). Breynin J (1): amorphous, colorless powder. [α]D22 −8.0 (c 0.05, MeOH); UV λmax (MeOH) nm (log ε): 257 (4.09); IR (KBr) cm−1: 3414, 2969, 2936, 2888, 1782, 1695, 1609, 1516, 1456, 1395, 1348, 1314, 1279, 1167, 1117, 1078, 1036, 854, 831, 773, 741, 700, 667, 619, 550, 511, 471; 1H and

• 13C NMR data, see Table 1 and Table 2. HRESIMS (m/z): [M + Na]+ calcd for C45H64O28SNa, 1107.3197; found, 1107.3177 . Epibreynin J (2): amorphous, colorless powder. [α]D22 −45.2 (c 0.05, MeOH); UV λmax (MeOH) nm (log ε): 257 (4.08); IR (KBr) cm−1: 3404, 2969, 2936, 2888, 1734, 1694, 1609, 1516, 1346

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• . Experimental General experimental procedures Column chromatography (60.4 cm length × 5.5 cm inner diameter) was carried out on silica gel 230–400 mesh (Merck). Analytical TLC was performed on Merck pre-coated silica gel 60 F254 plates, and spots were detected using ceric sulfate spray reagent and/or diluted

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• were recorded on a Modular Compact Polarimeter MCP 100 (Anton Paar, Graz, Austria). The temperature setting was 20 °C, the wavelength of the light used was 589 nm (sodium D line), the path-length was 10 cm, and compound concentrations c are given in g 100 mL−1. Synthesis of 2-Me-GPP To an Et2O (10 mL

Consecutive four-component synthesis of trisubstituted 3-iodoindoles by an alkynylation–cyclization–iodination–alkylation sequence

• Nadia Ledermann,
• Alae-Eddine Moubsit and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2023, 19, 1379–1385, doi:10.3762/bjoc.19.99

• absorption maximum of indole derivative 8b appears at 309 nm with an absorption coefficient ε = 10700 M−1 cm−1 and the emission maximum is found at 423 nm with a Stokes shift of 8700 cm−1 (Figure 1A). Moreover, compound 8b emits intensively blue in both the solid state and solution (Figure 1B). Conclusion In

• ), 7.23–7.26 (m, 1H), 7.46–7.54 (m, 5H); 13C NMR (150 MHz, CDCl3) δ 1.9 (Cquat), 32.4 (CH3), 106.7 (CH), 110.8 (CH), 111.5 (CH), 128.6 (Cquat), 129.3, 130.9, 131.5 (Cquat), 134.5 (Cquat), 143.5 (Cquat), 160.0 (Cquat); IR (cm−1) ν̃: 604 (w), 619 (w), 662 (w), 689 (s), 733 (m), 756 (s), 789 (m), 860 (w

• ), 128.5 (CH), 128.6 (CH), 129.1 (CH), 130.5 (Cquat), 131.0 (CH), 131.4 (Cquat), 131.7 (CH), 137.6 (Cquat), 142.9 (Cquat); IR (cm−1) ν̃: 611 (m), 621 (w), 664 (w), 679 (m), 691 (s), 702 (s), 754 (s), 787 (m), 806 (s), 870 (w), 916 (w), 970 (w), 1022 (w), 1069 (w), 1103 (w), 1148 (w), 1179 (w), 1209 (w

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• vibronically resolved carbazole absorption peaks which are commonly present at 325 nm [15]. Similar to 4CzIPN [14][15], the UV–vis profile has two broad regions: localized charge transfer (loCT) over 320–380 nm region with ε up to 14000 M−1 cm−1 and a delocalized charge transfer (deCT) broad shoulder over the

• region of ca. 380–460 nm with ε up to 1900 M−1 cm−1 (Table 2). Both loCT and deCT bands are observed for the benchmark material 4CzIPN [16] while originating from HOMO to LUMO transition in line with the theoretical calculations (Tables S1, S3, and S4, Supporting Information File 1). All CT bands

• (4) Å, b = 15.2552(3) Å, c = 20.8314(6) Å, β = 114.583(3)°, V = 5034.6(2) Å3, Z = 4, dcalc = 1.252 g cm−3, μ = 0.623 mm−1, yellow block, 33714 reflections measured (4.664° ≤ 2Θ ≤ 152.79°), 17837 unique (Rint = 0.0314, Rsigma = 0.0512) which were used in all calculations. The final R1 was 0.0462 (I

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• , 127.9, 127.5, 127.5, 127.1, 127.1, 127.0, 126.2, 125.9, 125.6, 124.9, 110.9, 110.3, 102.3, 62.3, 60.3, 50.0, 49.4, 44.4, 44.2, 42.5, 42.4, 32.9, 29.0, 27.6, 13.5 ppm; IR (KBr) ν: 3504, 3024, 3010, 2995, 2985, 1847, 1711, 1603, 1517, 1400, 1299, 1250, 1053, 953, 841 cm−1; HRMS (ESI-TOF): [M + Na]+ calcd

• , 1526, 1545, 1368, 1285, 1145, 1025, 956, 882 cm−1; HRMS (ESI-TOF): [M + H]+ calcd. for C48H44ClN3O5, 760.2937; found, 760.2921. Crystal structure of dispiro compound 3a. Crystal structure of compound 4a. Representative cascade reactions of Michael adducts of 3-methyleneoxindoles. Proposed reaction

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

• reported in hertz (Hz). Infrared (IR) spectra of the synthesized compounds were recorded in film or KBr on Perkin Elmer IR spectrometer and absorption maxima (υmax) are given in cm−1. UV–vis absorption and fluorescence spectra were recorded on an Analytik Jena’s Specord 250 UV–vis spectrophotometer and a

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• electrochemistry, the electron transfer occurs locally at the surface of the physical electrodes (typically located at a distance in the range of 200 μm to 2 cm) on which a potential is induced by an external potentiostat (Scheme 2). While for photoredox chemistry, the light-activated semiconductor catalyst

• = 365 nm, 96 W) at a distance of 0.5 cm from the reactor wall. In contrary with what has been reported previously for the catalyst-free oxidation under blue light irradiation [28], the reaction occurs also using water as the solvent (Table 1, entry 2). Running the reaction without adding extra water

• photocatalyst. Substrate scope with reaction times and isolated yields. 1 mmol (1 equiv) substrate was reacted in a 5 mL solution of CH3CN/H2O 8:2 (v:v). The reaction mixture was irradiated with a 365 nm 96 W lamp at a distance of 5 cm from the reactor. Oxygen was bubbled through the solution. a10 mL solution

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• characteristic water absorption at 3200–3600 cm−1 and the C=O band of CO2 at 2350 cm−1 during the both weigth losses but mainly CO2 at the first lump and predominantly water at the second loss. This also suggest a comparatively weak binding of the CO2. We determined the binding constant for CO2 to cyclodextrins

The unique reactivity of 5,6-unsubstituted 1,4-dihydropyridine in the Huisgen 1,4-diploar cycloaddition and formal [2 + 2] cycloaddition

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

Beilstein J. Org. Chem. 2023, 19, 982–990, doi:10.3762/bjoc.19.73

• , 3023, 2952, 2843, 1967, 1737, 1678, 1556, 1372, 1147, 1097, 1010, 957, 866, 759 cm−1; HRESIMS (m/z): [M + Na]+ calcd for C36H34NaN2O6, 613.2315; found, 613.2309. General procedure for the reaction of dialkyl acetylenedicarboxylate and 5,6-unsubstituted 1,4-dihydropyridine A mixture of dialkyl

• NMR (100 MHz, CDCl3) δ 169.3, 160.9, 160.7, 156.2, 152.0, 146.4, 144.5, 137.2, 136.1, 128.7, 128.5, 128.1, 127.9, 123.4, 101.1, 61.5, 61.4, 56.6, 53.8, 51.8, 51.0, 38.9, 17.3, 14.1, 14.1 ppm; IR (KBr) ν: 3746, 2983, 2945, 1729, 1651, 1557, 1434, 1347, 1251, 1129, 1088, 841, 732, 709 cm−1; HRESIMS (m/z

• , 1040, 914, 854, 769, 704 cm−1; HRESIMS (m/z): [M + Na]+ calcd for C29H30NaN2O8, 557.1894; found, 557.1891. Single crystal structure of the compound 4k. Single crystal structure of compound 5a. Single crystal structure of compound 6f. Various cycloaddition reactions of 5,6-unsymmetric 1,4

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• ), 7.59 (t, J = 7.5 Hz, 1H), 7.96 (d, J = 7.8 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 13.5 (CH3), 21.1 (CH3), 36.5 (CH), 49.8 (C), 62.7 (CH2), 67.8 (CH), 127.5 (C), 128.2 (CH), 128.3 (CH), 129.1 (CH), 129.5 (CH), 134.1 (CH), 135.1 (C), 138.3 (C), 164.3 (C), 186.6 (C); IR (ATR): 1362, 1557, 1682, 1695 cm−1

• ), 21.1 (CH3), 57.0 (CH), 60.6 (CH2), 107.7 (C), 108.9 (CH), 127.0 (CH), 127.7 (C), 128.0 (CH), 129.9 (CH), 130.0 (CH), 134.9 (C), 138.3 (C), 162.7 (C), 163.5 (C); IR (ATR): 1371, 1572, 1697 cm−1; HRESIMS–TOF (m/z): [M + H]+ calcd for C14H15NO4, 354.1336; found, 354.1324. Ethyl 4-(4-methylphenyl)-5-nitro

• (C), 125.6 (C), 127.3 (C), 128.4 (CH), 128.7 (CH), 128.9 (CH), 129.2 (CH), 131.2 (CH), 139.3 (C), 154.9 (C), 162.5 (C), Two signals were lacked presumably due to overlapping. IR (ATR): 1359, 1593, 1730 cm−1; HRESIMS–TOF (m/z): [M + Na]+ calcd for C19H19NO6, 374.0999; found, 374.1000. Monitoring the

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• = 844 000 M−1 cm−1 at 573 nm). A pair of enantiomers, (M,M)- and (P,P)-configuration was revealed by single crystal X-ray diffraction and optically pure samples of 125 were isolated by chiral HPLC. Meanwhile, a record high electronic circular dichroism (ECD) signal in the visible spectral range (Δε

• = 1375 M−1 cm−1 at 573 nm at 430 nm) for enantiopure 125 was obtained. In 2019, Wang and co-workers reported the largest atomically precise three-dimensional conjugated chiral nanographene propeller 128, representing the largest three-dimensional conjugated polyaromatics everprepared using scalable

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• revealed the presence of hydroxy (3429 cm−1) and carbonyl (1733 cm−1) groups. The UV absorption band maximum at λmax 283 nm and five downfield-shifted carbon signals at δC 169.8 (C-16), 163.8 (C-13), 149.3 (C-12), 111.6 (C-11), and 109.6 (C-15) in the 13C NMR data suggested the presence of the α,β

• colorless oil. The molecular formula was assigned to be C44H60O9 based on the HRESI–TOF–MS analysis with a [M + H]+ ion peak at m/z 733.4305 (calcd for C44H61O9, 733.4310) and NMR data, implying 15 degrees of unsaturation. The IR absorption band at 1724 cm−1 suggested the presence of α,β-unsaturated γ

• fruits of P. macropterum (0.2 kg) were ground and soaked with MeOH (3 × 2 L) at room temperature for 3 days. The solvent was evaporated under reduced pressure at 40 °C, affording MeOH extract (10.5 g). The extract was subjected to silica gel column chromatography (CC) (70–230 mesh, 2 × 60 cm) eluting

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• importantly, that the inlet of reactor 2 is at room temperature after passing through the tube of 50 cm that connects the two reactors. Hence, we rationalized such a performance improvement from a chemical point of view: the [Ru3(CO)12] complex is known to thermally degrade by deligation, resulting in the

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

• Martina Mamone,
• Giuseppe Gentile,
• Jacopo Dosso,
• Maurizio Prato and
• Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

• absorption spectra recorded in acetonitrile in 1 cm path quartz cuvettes. [DABCO]: 0.5 M; [2a]: 0.5 M. 1H NMR titration of DABCO in a solution of 2a in ACN-d3 to detect their halogen-bonding association through the shift of the signal of Hα. Proposed reaction mechanism for the photochemical alkylation of 1a

Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme

• Josipa Matić,
• Tana Tandarić,
• Marijana Radić Stojković,
• Filip Šupljika,
• Zrinka Karačić,
• Ana Tomašić Paić,
• Lucija Horvat,
• Robert Vianello and
• Lidija-Marija Tumir

Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40

• mmol) were used according to the general procedure. Phen-Py-1 was obtained as a white solid (9.4 mg, 56%). mp = 131–132 °C; Rf = 0,8 (CH2Cl2/MeOH 9:1); IR (KBr) νmax/cm−1: 3418 (s), 3294 (s), 3038 (m), 2947 (m), 2858 (m), 1738 (s), 1643 (s), 1582 (m), 1535 (m), 1435 (m), 1377 (m), 1209 (m), 843 (s

• ) were used according to the general procedure. Phen-Py-2 was obtained as a white solid (15.9 mg, 84%). mp = 230–231 °C; Rf = 0.8 (CH2Cl2:MeOH 9:1); IR (KBr) νmax/cm−1: 3435 (s), 3261 (s), 1740 (m), 1634 (s), 1531 (m), 849 (m), 760 (m); 1H NMR (CDCl3) δ 8.59 (d, J = 8.5 Hz, 1H, Phen-10), 8.51 (d, J = 7.3

• at the liquid–air interface, testing solutions with a 2 mL volume were used. Fluorescence and CD spectra were recorded using appropriate 1 cm path quartz cuvettes; UV–vis spectra were recorded in 1 cm path quartz cuvettes or using an immersion probe with 5 cm light path length. Isothermal titration

Mechanochemical solid state synthesis of copper(I)/NHC complexes with K₃PO₄

• Ina Remy-Speckmann,
• Birte M. Zimmermann,
• Mahadeb Gorai,
• Martin Lerch and
• Johannes F. Teichert

Beilstein J. Org. Chem. 2023, 19, 440–447, doi:10.3762/bjoc.19.34

• -methylguanidino)ethyl)-3-mesityl-1H-imidazol-3-ium bromide (3, 75 mg, 0.16 mmol, 1.0 equiv), CuCl (17 mg, 0.16 mmol, 1.0 equiv) and K3PO4 (53 mg, 0.25 mmol, 1.5 equiv) were filled into a 12 mL steel vessel equipped with six steel balls (1 cm diameter). The beaker was sealed in an argon-filled glovebox. Milling

• procedure: steel vessel (12 mL), 6 steel balls (1 cm diameter), 450 rpm, 4 h). (dimer = [(NHC)2Cu+]Cl−). Supporting Information Supporting Information File 36: General procedures, experimental details, analytical data and copies of NMR spectra. Acknowledgements Prof. Dr. Martin Oestreich (TU Berlin) is

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• 1023.2 (± 1.1) cm−1 along the second PCA component (PC2), respectively. The wavenumbers were more appropriate for discrimination than the corresponding intensities of the specific FTIR bands. On the other hand, ternary complexes were clearly distinguishable from the starting β-CD hydrate along the first

• component (PC1) by all FTIR band intensities and along PC2 by the wavenumber of the asymmetric stretching vibrations of the CH groups at 2922.9 (± 0.4) cm−1 for ternary complexes and 2924.8 (± 1.4) cm−1 for β-CD hydrate. The first two PCA components explain 70.38% from the variance of the FTIR data (from a

• especially appear for OH, CC and CH/CH2 bonds and groups. However, CD specific bands also appear for CH groups in the CD ring and α-type glycosidic bonds. Thus, a broad FTIR band corresponding to the stretching vibration of the O–H bonds in β-CD and hydration water molecules appears at ≈3301 cm−1. A weak

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23