Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• configuration comprising indium–tin oxide (ITO) as the bottom electrode, a few μm thick organic layer as the active medium, and aluminum as the top electrode. The entire deposition process was carried out under a vacuum exceeding 2 × 10−6 mbar to ensure the integrity and purity of the layers. In our TOF setup

• × ttr), where d represents the thickness of the organic layer, and U corresponds to the applied voltage over the sample. Cyclic voltammetry (CV) measurements were conducted using a mAUTOLAB type III galvanostat, employing a glassy carbon working electrode in a three-electrode cell configuration. The

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• ][10], potentially opening a path for its use in treating KRAS-induced cancers. A common characteristic of the degraders elaborated in the literature involves the compulsory integration of an E3-ligase ligand motif into the PROTAC configuration [11]. The E3-ligase most frequently utilized in TPD

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• product was purified by preparative thin-layer chromatography (SiO2, hexane/ethyl acetate 2:1, Rf 0.36) to obtain the product (S)-14 as pale-yellow crystals. The products had the same spectroscopic data than those of reported (the absolute configuration was determined by the optical rotation of the

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• recent study by Eedugurala et al., a terachlorobenzene ring were fused to the [1,2,5]thiadiazolo[3,4-g]quinoxaline unit in the polymer backbone of Qx6 which enhanced the stability of the polymer and led to its high-spin configuration compared to the analogous material Qx5 featuring 6,7-dimethyl-[1,2,5

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

• -(1,2,2-triphenylvinyl)phenyl)-9H-carbazol-3-yl)naphtho[2,3-c][1,2,5]thiadiazole (TPECNz), built on a D–A–D type structure was designed and synthesized (Scheme 1). The D–A–D configuration was constructed by incorporating a second symmetrical donor in the D–A framework, which could further reduce the

• configuration with dihedral angles of 54–56° between the planes of the terminal carbazole donors and the Nz acceptor that are beneficial for the state mixing between the LE and CT states. The lowest unoccupied molecular orbital (LUMO) was mainly localized on the Nz ring, while the highest occupied molecular

• of the twisted configuration between them as observed in the optimized structure (Figure 1a) [47]. In solution, TPECNz exhibits a strong deep-red emission with the PL spectrum (λem = 648 nm) described by a broad PL band (FWHM = 120 nm) that reflects the corresponding ICT absorption band well

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

• ) in 1D and 2D ROE spectroscopy (ROESY) suggested that the relative configuration of the aglycone in 1 is identical to that in breynin B (6). The remaining NMR resonances (Table 2) were attributed to a tetrasaccharide based on the observation of four anomeric methine signals at δC 103.2 (C-1′), 104.5

• reduce computational costs (Figure 3a). The calculated ECD curve for 1′ agreed well with the experimental ECD spectra of 1 and 6, indicating that the aglycones of these compounds had an absolute configuration of 1R,3R,4R,6S,7R,9S,11S,12R,16S,17S (Figure 3b). Similarly, the absolute configurations of

• substituent at C-17 and the same relative configuration as 5 otherwise, as supported by the SSCC and NOE observed in the 1H NMR, NOESY, and J-resolved spectra. As the computed and experimental ECD curves of 3 were in good agreement, the absolute configuration of compound 3 was established as 4R,6S,7R,9S,11S

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• ZnMe2 (entries 9 and 10). This difference can be ascribed to a less favorable homolytic substitution reaction of ZnMe2 in relation to its higher analogues and is in line with previous literature observations [11]. The configuration of the major diastereomer was determined by chemical correlation (Scheme

• concomitant deprotection of the nitrogen and the ester groups. The sample was found to have a negative optical rotation, thereby indicating that the major enantiomer present had S configuration [26]. This allowed to establish that the configuration of the major diastereomer present in (RS)-14b was (RS,S), and

• 5 and 8a in 77–88% yields, albeit as poorly selective mixtures of diastereoisomers. This lack of stereocontrol is not surprising, given the well-known difficulty to control the relative configuration between the two adjacent stereocenters created during aldol condensations with zinc enolates

Correction: Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 1370–1371, doi:10.3762/bjoc.19.97

• theoretical ECD spectra of both enantiomers to determine the absolute configuration. By comparison of the recalculated and the experimental spectra, it became evident that in fact, the (3S,4S)-enantiomer rather than the (3R,4R)-enantiomer was obtained (Figure 2). Consequently, in the first paragraph of the

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• alkenyl compounds, the vinyl ether function is characterized by a (Z)-configuration as shown in Figure 1. In addition, an acyl group is present on the secondary alcohol of the glycerol. This acyl group is constituted by a saturated or unsaturated lipid chain or, in the case of platelet-activating factor

• (PAF), by an acetyl group (R2 = CH3) [1]. The asymmetric carbon of the glycerol (sn-2 position) features a R configuration. The last substituent attached to the glycerol unit is a polar head group mostly constituted by a phosphatidylethanolamine group (PE) or a phosphocholine moiety (PC). ELs with

• produces the diester 4.12 with an inversion of the configuration of the chiral carbon atom. Then, 4.12 was hydrolyzed in the presence of KOH to produce 4.10. The installation of the phosphocholine group was achieved following two schemes: a) Starting from the diol 4.10 (Figure 4C), tritylation and

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

• (CV) was performed using a three-electrode configuration consisting of a glassy carbon macrodisk working electrode (GCE) (diameter of 3 mm; BASi, Indiana, U.S.A.) combined with a Pt wire counter electrode (99.99%; GoodFellow, Cambridge, U.K.) and an Ag wire pseudoreference electrode (99.99

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

• effect. The single crystal structure of compound 3a was determined by X-ray crystallographic diffraction (Figure 1). From Figure 1 it can be seen that the two scaffolds of oxindole at neighboring positions are in trans-configuration. The ethoxycarbonyl group is also in trans-position to the carbonyl

• group in the neighboring oxindole scaffold. Therefore, it can be concluded that the obtained dispiro compounds 3a–m have this kind of relative configuration on the basis of 1H NMR spectra and crystal structure determination. It should be pointed out that ammonium acetate was employed as nitrogen source

• is largely general. The 1H NMR spectra of the obtained compounds 4j–p clearly show similar chemical shifts of the characteristic groups as the spiro compounds 4a–i. Therefore, it can be concluded that the spiro compounds 4j–p have the same relative configuration as the spiro compounds 4a–i. In order

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• positions were notably confirmed to be at C-3 and C-21, respectively. The ᴅ-configuration of the β-glucopyranosyl unit was assumed to be the one found in related fungal lanostanosides namely; ganosinoside A from Ganoderma sinense [26], fomitosides I and J from Fomitopsis pinicola [34]. Concerning the

• configuration at C-3', it was assigned as S by careful comparison of the 1H and 13C NMR data of compound 1 with those of related lanostane derivatives comprising the 3-hydroxy-3-methylglutaryl moiety produced by some fungi including Fomitopsis pinicola [23], Piptoporus betulinus [13], and Pholiota populnea [35

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• the correlation of H3-15/H2-6 (Figure 3), which results in ambiguity in the relative configuration assignment of 1. Thus, NMR chemical shift calculations and ECD calculations were used to confirm the relative and absolute configuration of 1. More specifically, NMR calculations were carried out at the

• calculations. The CD spectrum matched well with the calculated ECD spectrum of 1a (Figure 4), revealing the absolute configuration of 1 to be 7R,10S, and it was named aquisinenoid F. Compound 2 was isolated as pale yellow gum, and was assigned the molecular formula C15H24O2 as inferred from the HRESIMS m/z

• planer structure of 2 was obtained (Figure 1). The relative configuration of 2 was established by careful interpretation of the ROESY correlations (Figure 3). The ROESY correlations of H-8/H3-15 and Ha-6/H3-15 and the coupling constant of H-7 (JH-7, Ha-6 = 3.8 Hz) suggest the relative configurations (7S

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

• a high diastereoselectivity. From Figure 1, it can be seen that the three protons and the phenyl group have cis-configuration in the hexahydro-1,6-naphthyridyl ring. During the investigation of the above three-component reaction, we found that the three-component reaction of isoquinoline, dimethyl

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• substituent at C-2 of the phenol moiety. The final carbon atom at 171.9 ppm (C-15) could be attributed to a carboxylic acid function with HMBC correlations from H-13 and H-14, thereby completing the determination of the planar structure of 1. To determine the configuration of 1, we measured its optical

Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO₂F₂)

• Xian-Lin Chen and
• Hua-Li Qin

Beilstein J. Org. Chem. 2023, 19, 901–908, doi:10.3762/bjoc.19.68

• the construction of a range of δ-olefin-containing aliphatic nitriles with (E)-configuration selectivity. This new method features wide substrate scope, mild conditions, and direct N–O activation. Keywords: direct N–O activation; E-selectivity; nitrile synthesis; ring-opening cross-coupling; sulfuryl

• -containing aliphatic nitriles possess E-configuration at the double bond. This transformation could be easily activated by SO2F2 in situ without the need of pre-introduction of electrophores. Representative nitrile-containing functional materials, drug carriers, and medicines. Activating protocol of

Asymmetric tandem conjugate addition and reaction with carbocations on acylimidazole Michael acceptors

• Brigita Mudráková,
• Renata Marcia de Figueiredo,
• Jean-Marc Campagne and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 881–888, doi:10.3762/bjoc.19.65

• , the configuration at the position C-3 is determined by the chiral ligand L1 and was determined previously as (R) [19]. To gain insight into the reactivity of enolates formed in this transformation, we evaluated properties of Zn enolates by DFT calculations (Figure 2). The corresponding (E) and (Z

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• configuration of the products by modifying the substituents on the nitrogen of the pyridinium salts. Further, the method showed a wide substrate scope for both the Z- and E-alkenylated products in which Z-selectivity was achieved when N-methylpyridinium salts were used and E-selectivity when N-benzylpyridinium

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• relative configuration of the cyclohexanone segment in 1. The small coupling constant (J3,4 = 3.0 Hz) indicated that H-3 and H-4 are on the same side of the ring, corroborated by the literature [18]. The absolute configuration of compound 1 was identified as 3R,4R in accordance with the experimental and

• compound 4. According to the literature [22], the absolute configuration at C-2 for 4 was assigned as S, from the Cotton effects in its ECD curve (Figure S26 in Supporting Information File 1) [283 nm (Δε −0.71)]. The absolute configuration of 4 was determined as 2S,2″R based on the comparison of the

• configuration was E. However, the overlapping signals of H2-5 and H2-8 made it difficult to determine the geometry of the ∆6,7 in the same manner. By comparing the 1H and 13C chemical shifts with those of similar compounds [24][25][26][27][28], the geometry of the ∆6,7 was determined to be E. The configuration

Bromination of endo-7-norbornene derivatives revisited: failure of a computational NMR method in elucidating the configuration of an organic structure

• Demet Demirci Gültekin,
• Arif Daştan,
• Yavuz Taşkesenligil,
• Cavit Kazaz,
• Yunus Zorlu and
• Metin Balci

Beilstein J. Org. Chem. 2023, 19, 764–770, doi:10.3762/bjoc.19.56

• configuration in a molecule, in short, it is the single most important spectroscopic tool aside from X-ray crystallography to provide an accurate ensemble-guided view of the structure, even conformational dynamics in a molecule. Quantum mechanical/nuclear magnetic resonance (NMR) approaches are used for the

• experiments. The aforementioned authors, Novitskiy and Kutateladze, however, claimed in their paper [3] that the assigned configuration of product 6 was wrong. They revised the structure 6 to an isomeric symmetric anti-7-bis-exo-tribromide 7 (Figure 1). Below, we will briefly discuss how we initially

• elucidated the exact configuration of compound 6. The symmetrical structure of 6 could be characterized easily because of its four-line 13C NMR spectrum. However, on the basis of 13C NMR data alone we were not able to distinguish between possible symmetrical tribromides. The configurations of the bromine

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

• nanoribbon is 4.3 nm in length, with an end-to-end twist of 117° as indicated by single-crystal X-ray diffraction. Except for the helical conformation, two other isomers, in the waggling or mixed configuration were also generated in the last oxidative cyclodehydrogenation step, and they could be separated

• = 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

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

• -17 and C-14 as well as the appearance of the H3-17 as a singlet signal confirmed the connection of a hydroxy group at C-14. The relative configuration of 1 was characterized by NOESY spectra. In the NOESY experiment (Figure 3), the cross-peak between H-8 and H3-20 suggested these protons to be syn

• oriented. In addition, the cross-peaks between H-5/H-9, H-5/H-7α and H-7α/H3-17 suggested H3-17 to be α-oriented. Comparison of the specific rotation was used to establish the absolute configuration of 1. The specific rotation of 1 ( −22 (c 0.01, MeOH)) was similar to the reported data of 2 ( −36 (c 0.01

• , MeOH); lit. −44 (c 0.05, MeOH)) [18], confirming the same absolute configuration these compounds should be derived from the same biosynthetic pathway. In addition, the ECD spectra of (5S,8R,9S,10R,14S)-1 and its enantiomer were calculated at the B3LYP functional using a TD–DFT method [19]. As

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• NMR experiments (Hα coupling constants ≈ 6.4–8.6 Hz), the high level of diastereocontrol can be associated with the preferred Z-configuration of the cyclic copper enolate intermediate. In the presence of the chiral ligand (R,S)-L17, the tandem reaction was accomplished in a highly enantioselective way

• Indonesian sponge Haliclona sp. [108]. Their synthesis takes advantage of the same tandem procedure that gives β-ketoester 219. The asymmetric conjugate 1,4-addition and subsequent acylation provided good stereocontrol and the authors could revise the thus far incorrectly assigned configuration of the target

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

• exceeding 10 bar. Hence, we worked at about 7.5 bar to stay below the boiling curve of toluene in the temperature range used (180–200 °C). The first experiments performed with this configuration allowed us to validate our hypothesis, namely the possibility of directly functionalizing furfural by forming the