Synthesis and cytotoxicity studies of novel N-arylbenzo[h]quinazolin-2-amines

• Battini Veeraiah,
• Kishore Ramineni,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Hélène Solhi,
• Rémy Le Guevel,
• Chada Raji Reddy,
• Frédéric Justaud and
• René Grée

Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218

• bromides and other reagents were used as they were received from commercial suppliers, unless otherwise noted. THF and Et2O were dried over sodium-benzophenone and distilled prior to use. 1H NMR spectra were recorded at 300 and 400 MHz, and 13C NMR spectra at 75 and 100 MHz, in CDCl3 or DMSO-d6 using TMS

• , filtered and dried to get compound 3 as a brown colored solid (63% yield). 1H NMR (400 MHz, DMSO-d6, δ ppm) 9.06 (s, 1H), 8.91 (d, J = 8.0 Hz, 1H), 7.93 (d, J = 7.6 Hz, 1H), 7.76–7.64 (m, 3H), 7.56 (d, J = 8.8 Hz, 1H), 6.99 (br s, 2H); 13C NMR (75 MHz, DMSO-d6, δ ppm) 162.18, 161.31, 152.03, 136.05, 130.07

• , 129.07, 128.36, 126.72, 124.51, 124.38, 122.67, 116.44; 1H-13C NMR ((300, 75) MHz, DMSO-d6, δ ppm) (9.09 161.23), (8.95 124.31), (7.95 128.17), (7.76 129.93), (7.69 126.77), (7.61 124.66), (7.58 122.55); FTIR (KBr 1%, cm−1) ν̃: 3440, 3316, 3192, 1625, 1611, 1598, 1571, 1496, 1471, 1460, 1410, 801, 763

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• formation of various unidentified byproducts. The obtained tetronic acids 4 are solid crystalline compounds, whose structure was proved by 1H, 13C NMR spectroscopy and high-resolution mass spectrometry. The 1H NMR spectra of the synthesized products contain characteristic signals of protons of the methyl

• solvent signals (DMSO-d6: 2.50 ppm (1H NMR) and 39.52 ppm (13C NMR)). High-resolution mass spectra (HRMS) were obtained on a Bruker micrOTOF II instrument using electrospray ionization (ESI). The melting points were determined on a Kofler hot stage apparatus. A magnetic stirrer IKA C-MAG HS 7 was used for

• -ylidene)furan-2,4(3H,5H)-dione (4a). Pale yellow powder; yield 62% (0.25 g); mp 121–123 °C; 1H NMR (300 MHz, DMSO-d6) δ 7.31–7.13 (m, 5H), 4.34 (t, J = 7.5 Hz, 2H), 2.74 (t, J = 7.6 Hz, 2H), 2.56–2.48 (m, 2H in DMSO), 2.46 (s, 3H), 2.14 (t, J = 11.8 Hz, 2H), 1.64–1.54 (m, 3H), 1.41–1.09 (m, 5H); 13C NMR

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• , 0.209 mmol, 19%) as a red solid. Rf 0.33 (MeOH/EtOAc/CH2Cl2 1:2:8); 1H NMR (600 MHz, CDCl3, 20 °C) δ (ppm) 7.68 (t, J = 8.4 Hz, 3H, TATA-H), 7.51 (t, J = 7.8 Hz, 3H, Ar-H), 7.44 (d, J = 7.8 Hz, 6H, Ar-H), 6.37 (d, J = 8.4 Hz, 6H, TATA-H), 2.10 (s, 18H, CH3); 13C NMR (151 MHz, CDCl3, 20 °C) δ (ppm

• , TATA-H), 2.11 (s, 18H, CH3); 13C NMR (151 MHz, CDCl3, 20 °C) δ (ppm) 142.40, 140.77, 138.59, 136.46, 135.03, 130.73, 130.69, 110.66, 106.15, 17.61; 19F NMR (564 MHz, CDCl3, 20 °C) δ (ppm) −77.26 (d, J = 712 Hz, 6F); UV–vis (CH3CN), λmax, nm (ε, 105 M−1 cm−1): 272 (1.30), 337 (0.07), 349 (0.09), 523

• ) 7.68 (t, J = 8.4 Hz, 3H, TATA-H), 7.51 (t, J = 7.8 Hz, 3H, Ar-H), 7.44 (d, J = 7.2 Hz, 6H, Ar-H), 6.38 (d, J = 8.4 Hz, 6H, TATA-H), 2.11 (s, 18H, CH3); 13C NMR (151 MHz, CDCl3, 20 °C) δ (ppm) 148.27 (d, J13C–19F = 242 Hz), 142.18, 140.70, 138.92, 138.22 (d, J13C–19F = 241 Hz), 135.98, 136.31 (d, J13C

Visible-light-mediated flow protocol for Achmatowicz rearrangement

• Joachyutharayalu Oja,
• Sanjeev Kumar and
• Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

• corresponding products (3o, 3p) in good yields. All the products obtained were characterized by 1H NMR, 13C NMR and mass spectrometry techniques. A plausible catalytic cycle has been postulated based on a literature study [13], and is shown in Figure 2. With the exposure of photocatalyst to sunlight/LED light

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• . However, the comparison of their specific region of the 13C NMR charts and sharp peaks readily led us to qualitative understanding of the high purity of 11a-D possibly as a single diastereomer (Figure 3). Conclusion As described above, we have succeeded in the facile preparation of 2,3-epoxyesters 2 with

• column chromatography using AcOEt/Hex 1:20 as an eluent, 0.2117 g (0.86 mmol) of the title compound (86% yield) were isolated. Rf 0.52 (Hex/AcOEt 5:1); 1H NMR (300.40 MHz, CDCl3) δ 3.71–3.76 (m, 2H), 5.21 (d, J = 12.3 Hz, 1H), 5.28 (d, J = 12.3 Hz, 1H), 7.34–7.44 (m, 5H); 13C NMR (75.45 MHz, CDCl3) δ

• –6.81 (m, 4H), 7.26–7.36 (m, 5H); 13C NMR (75.45 MHz, acetone-d6) δ 55.5, 59.3, 67.9, 70.0 (q, J = 30.2 Hz), 114.8, 117.7, 124.1 (q, J = 283.5 Hz), 128.5, 128.6, 128.7, 134.4, 139.5, 154.3, 170.2; 19F NMR (282.65 MHz, CDCl3) δ −76.83 (d, J = 9.0 Hz); IR (KBr) ν: 3454, 3315, 2955, 2924, 2854, 2360, 1741

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO

• Hisanori Senboku and
• Mizuki Hayama

Beilstein J. Org. Chem. 2024, 20, 2392–2400, doi:10.3762/bjoc.20.203

• ) [36], and phenyl(thiophen-2-yl)acetic acid (2l) [30] are known compounds, and their spectral data were good agreement with previously reported values. Spectral data of the products 2 Diphenylacetic acid (2a): 1H NMR (400 MHz, CDCl3, δ) 5.05 (s, 1H), 7.25–7.34 (m, 10H); 13C NMR (100 MHz, CDCl3, δ) 56.9

• , 127.5, 128.7 (× 2), 137.8, 178.1. (4-Methylphenyl)phenylacetic acid (2d): 1H NMR (400 MHz, CDCl3, δ) 2.32 (s, 3H), 5.01 (s, 1H), 7.14 (d, J = 8.2 Hz, 2H), 7.21 (d, J = 8.2 Hz, 2H), 7.25–7.29 (m, 1H), 7.31–7.32 (m, 4H); 13C NMR (100 MHz, CDCl3, δ) 21.0, 56.6, 127.4, 128.5, 128.59, 128.61, 129.3, 134.9

• , 137.2, 138.0, 178.9. (4-Methoxyphenyl)phenylacetic acid (2e): 1H NMR (400 MHz, CDCl3, δ) 3.78 (s, 3H), 4.99 (s, 1H), 6.86 (d, J = 8.7 Hz, 2H), 7.24 (d, J = 8.7 Hz, 2H), 7.23–7.32 (m, 5H); 13C NMR (100 MHz, CDCl3, δ) 55.2, 56.1, 114.0, 127.4, 128.5, 128.6, 129.7, 129.9, 138.3, 159.0, 179.2. Bis(4

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

• Yuri A. Sidunets,
• Valeriya G. Melekhina and
• Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

• , indicating that the developed tandem protocol does not depend on the presence of the N-oxide moiety in the parent heterocycle. All synthesized triazinones 1 and 7 were fully characterized by IR, 1H and 13C NMR spectroscopy, and high-resolution mass spectrometry. The structure of compounds 1b and 7h was

• . Supporting Information Supporting Information File 96: Experimental procedures, characterization data of all products, copies of 1H, 13C NMR, 15N spectra of new compounds, DSC curves,X-ray crystallographic data and copies of IR spectra. Acknowledgements The crystal structure determination was performed at

gem-Difluorination of carbon–carbon triple bonds using Brønsted acid/Bu₄NBF₄ or electrogenerated acid

• Mizuki Yamaguchi,
• Hiroki Shimao,
• Kengo Hamasaki,
• Keiji Nishiwaki,
• Shigenori Kashimura and
• Kouichi Matsumoto

Beilstein J. Org. Chem. 2024, 20, 2261–2269, doi:10.3762/bjoc.20.194

• of spectra of 1H NMR and 13C NMR. Acknowledgements We are grateful for Kindai University Joint Research Center for use of facilities. Funding This work was supported in part by JSPS KAKENHI Grants JP20K05588 (Grant-in-Aid for Scientific Research (C)). We appreciate 2021 Kindai University Research

Synthesis and reactivity of the di(9-anthryl)methyl radical

• Tomohiko Nishiuchi,
• Kazuma Takahashi,
• Yuta Makihara and
• Takashi Kubo

Beilstein J. Org. Chem. 2024, 20, 2254–2260, doi:10.3762/bjoc.20.193

• O–O bond cleavage to give compounds 1 and 5 (Scheme 2). Owing to the high reactivity of the DAntM radical, cyclic voltammogram (CV) was measured by using the stable DAntM cation, prepared from compound 3 oxidized by antimony(V) chloride, which can be characterized by 1H, 13C NMR, and UV–vis

• . Decomposition pathway of the DAntM radical under air conditions. Supporting Information Supporting Information File 81: Synthetic procedure and compound characterization data (1H, 13C NMR, MS, melting point, X-ray crystallography) of new compounds. DFT calculation results and optimized structural Cartesian

Metal-free double azide addition to strained alkynes of an octadehydrodibenzo[12]annulene derivative with electron-withdrawing substituents

• Naoki Takeda,
• Shuichi Akasaka,
• Susumu Kawauchi and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2024, 20, 2234–2241, doi:10.3762/bjoc.20.191

• . Chemical shifts of NMR were reported in ppm relative to the residual solvent peak at 7.26 ppm for 1H NMR spectroscopy and 77.6 ppm for 13C NMR spectroscopy. Coupling constants (J) were given in Hz. The resonance multiplicity was described as s (singlet), t (triplet), and m (multiplet). FTIR spectra were

• , 300 MHz, 297 K) δ 8.40 (s, 2H), 7.80 (s, 2H), 7.40–7.18 (m, 10H), 5.53 (s, 4H), 4.34–4.29 (m, 8H), 1.74–1.71 (m, 8H), 1.37–1.32 (m, 24H), 0.92–0.88 (m, 12H); 13C NMR (CDCl3, 75 MHz, 297 K) δ 166.26, 147.55, 135.76, 133.90, 133.67, 133.36, 131.92, 130.83, 128.74, 128.70, 128.34, 120.99, 119.57, 103.11

Selective hydrolysis of α-oxo ketene N,S-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides

• Haifeng Yu,
• Wanting Zhang,
• Xuejing Cui,
• Zida Liu,
• Xifu Zhang and
• Xiaobo Zhao

Beilstein J. Org. Chem. 2024, 20, 2225–2233, doi:10.3762/bjoc.20.190

• ]. Supporting Information Supporting Information File 68: Analytic data and copies of 1H and 13C NMR spectra of compounds 2 and 3. Funding We are grateful to Funds for the Natural Science Foundation of Jilin Province, China (20240101156JC, 20210101128JC) and the Program for Innovative Research Team of Baicheng

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• purified through silica-gel column chromatography. After successfully synthesizing these easy-to-make yet interesting molecules, they were fully characterized by means of the standard spectroscopic techniques (1H NMR, 13C NMR and HRMS). We are of the opinion that these truxene-based systems will be useful

• derivatives were successfully characterized and their structures were established by means of the 1H and 13C NMR spectroscopy, besides further confirmation by mass spectrometry (see Supporting Information File 1). The UV–vis absorption, emission and time-resolved fluorescence spectra Emission and absorption

• like 1H NMR, 13C NMR, and mass spectral data. The preliminary UV–vis absorption as well as fluorescence emission spectral data for thus prepared truxene-based compounds were recorded in chloroform and compared as well. Additionally, time-resolved fluorescence lifetime decays were also measured for thus

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

• Kateryna V. Dil and
• Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

• /9.26→9.75/10.50→10.26/10.85 ppm) and become more equivalent (Δδ = 1.39→0.75→0.59 ppm accordingly). The key signal in the 13C NMR spectra is located in the regions 174.04–174.69 ppm (C=S), 151.44–151.86 ppm (C=O), and 170.15–170.91 ppm (C=Se) accordingly. Utilization of reaction products The Biginelli

Allostreptopyrroles A–E, β-alkylpyrrole derivatives from an actinomycete Allostreptomyces sp. RD068384

• Marwa Elsbaey,
• Naoya Oku,
• Mohamed S. A. Abdel-Mottaleb and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2024, 20, 1981–1987, doi:10.3762/bjoc.20.174

• . Analysis of 1H NMR, 13C NMR (Table 1), and HSQC spectra revealed a formyl group (δC 186.3/δH 9.89), an olefinic methine (δC 131.1/δH 7.64), an acyl carbonyl carbon (δC 163.3), three non-protonated olefinic carbons (δC 133.4, 126.4, and 123.1), a deshielded non-protonated sp3 carbon (δC 70.1), six sp3

• -configurations were proposed for compounds 2 and 3. However, this prediction was not confirmed by chemical derivatization due to their limited availability. 1H and 13C NMR spectra of compounds 4 and 5 were superimposable to those of 1 except for methylene resonances, supporting that both 4 and 5 possess the same

• total 6.5 mg of 1, 3.1 mg of 2, 2.6 mg of 3, 7.2 mg of 4, and 5.6 mg of 5 from 12 L culture. Allostreptopyrrole A (1): greenish yellow amorphous solid; UV (MeOH) λmax nm (log ε) 234 (3.86), 273 sh (3.44); IR (ATR) νmax: 3275, 2964, 2928, 2855, 1658, 1554, 1418 cm−1; 1H and 13C NMR data, see Table 1

1,2-Difluoroethylene (HFO-1132): synthesis and chemistry

• Liubov V. Sokolenko,
• Taras M. Sokolenko and
• Yurii L. Yagupolskii

Beilstein J. Org. Chem. 2024, 20, 1955–1966, doi:10.3762/bjoc.20.171

• ], respectively, while reference [68] provides UV-spectral data of both isomers. 1H, 19F, and 13C NMR data [69][70] are given in Table 2. Chemistry of HFO-1132 Isomerization Iodine-catalyzed cis–trans isomerization of 1,2-difluoroethylene and corresponding equilibrium measurements were described in the 1960s [47

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• : Characterization of all compounds (1H NMR, 13C NMR, LC–MS, IR), and crystallographic methods and data for products P1 and P2. Supporting Information File 23: DFT methods, relative energy comparisons, TS imaginary frequencies, and XYZ coordinates. Supporting Information File 24: GoodVibes outputs. Acknowledgements

A new platform for the synthesis of diketopyrrolopyrrole derivatives via nucleophilic aromatic substitution reactions

• Vitor A. S. Almodovar and
• Augusto C. Tomé

Beilstein J. Org. Chem. 2024, 20, 1933–1939, doi:10.3762/bjoc.20.169

• apparatus. NMR spectra were recorded on a Bruker DRX 300 Avance operating at 300.13 MHz (for 1H NMR), at 75.47 MHz (for 13C NMR) and 282 MHz (for 19F NMR). Deuterated chloroform (CDCl3) was used as the solvent and tetramethylsilane (TMS) as the internal reference. The chemical shifts (δ) are expressed in

• ), 5.03 (s, 4H); 13C NMR (75 MHz, CDCl3) δ (ppm) 161.7, 147.2, 138.01, 129.8, 129.6, 125.6, 110.0, 29.7; 19F NMR (282 MHz, CDCl3) δ (ppm) −138.11 to −138.29 (m, 4F), −149.90 (t, J = 21.4 Hz, 2F), −157.63 to −157.91 (m, 4F); ESIMS m/z: 717.0 (M + H+, 100%). General procedure for the nucleophilic aromatic

• –7.64 (m, 4H), 7.52 (AA’BB’, J = 8.7 Hz, 4H), 7.07 (AA’XX’, J = 6.3 Hz, 2H), 5.15 (s, 2H), 5.05 (s, 2H); 13C NMR (125 MHz, CDCl3) δ (ppm) 161.7, 149.7, 147.6, 146.95, 145.9, 138.1, 129.9, 129.6, 125.6, 121.1, 109.9, 109.7, 34.9, 34.5; 19F NMR (282 MHz, CDCl3) δ (ppm) −126.79 to −126.90 (m, 2F), –135.53

Electrochemical radical cation aza-Wacker cyclizations

• Sota Adachi and
• Yohei Okada

Beilstein J. Org. Chem. 2024, 20, 1900–1905, doi:10.3762/bjoc.20.165

• cyclization.a Supporting Information Supporting Information File 6: General remarks and characterization data, including copies of 1H and 13C NMR spectra. Funding This work was supported in part by JSPS KAKENHI Grant No. 22K05450 (to Y. O.), and TEPCO Memorial Foundation (to Y. O.).

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• -aryldeazaalloxazines in any case. Finally, the unsubstituted derivative 2x was formed with a yield of only 15% using DMF/AlCl3. The isolated products 2a–x were characterized by 1H, 13C NMR and mass-spectral methods. The 1H NMR spectra of 5-aryldeazaalloxazines 2a–x, along with protons of aryl substituents of aldehyde

• moiety and pyrimido[4,5-b]quinoline core, contained singlets with 3H intensity of the N(1)–CH3 and N(3)–CH3 groups of the barbituric acid fragment at 3.20–3.56 ppm. The 13C NMR spectra of 5-aryldeazaalloxazines 2a–x were represented by groups of singlets at 27.9–57.2 and 100.0–160.5 ppm. The

• unexpected structure of product 6 was confirmed by 1H, 13C NMR and mass spectrometry. The main feature of the 1H NMR spectrum of compound 6 is the absence of the signals of the aromatic aldehyde moiety and the appearance of the singlet of the 5-CH methyne group at 9.56 ppm and the singlets of the protons of

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides

• Samuel M. G. Dearman,
• Xiang Li,
• Yang Li,
• Kuldip Singh and
• Alison M. Stuart

Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157

• ppm and 7.96 ppm, respectively, for iodine(V) product 6. Similarly, the 13C NMR spectrum showed a major downfield shift for the aromatic carbon attached to iodine from a chemical shift of 105.3 ppm in iodine(III) substrate 10 to 132.4 ppm for difluoroiodane(V) product 6. Since Selectfluor was shown to

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• stirring for three hours (Scheme 3, conditions A). However, the results of this attempted post-Ugi transformation were quite unexpected: Instead of acid 11, we isolated the amide of the unsaturated derivative of pyruvic acid 10a according to the 1H and 13C NMR spectra and mass spectrometry data. In order

• conventional thermal heating, amide 10a was isolated, albeit in a lower yield and accompanied with tar formation. In addition to the 1H, 13C NMR spectra and mass spectrometry data, the structure of compound 10d was established by X-ray diffraction analysis (Figure 3). It was also found that the substituents at

• case of bisamides 5d, 6a, 6c, 7b, 8a, and 8c (Table 2), additional transformation products were also isolated from the reaction mixture. According to 1H and 13C NMR, MS, and X-ray diffraction studies these were the corresponding ketobisamides 12, which are products of a nucleophilic substitution of the

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• for 35Cl and 37Cl isotopes, respectively, with an approximately 3/4 and 1/4 proportion. The symmetry of the obtained compound TP1 gives simple NMR spectra, with the 31P NMR spectrum showing a singlet signal (Figure 2) and the signal at 169.5 ppm, on the 13C NMR spectrum, confirming the presence of a

• different conditions tested. The spectroscopic data are in agreement with the proposed structure for compound TP3 (Scheme 5), namely the presence of the chlorine atom in the mass spectrum, due to the presence of isotope peaks, the signal at 168.2 ppm at 13C NMR spectrum attributed to the carbon atom bonded

• 400 (1H 400 MHz, 13C NMR 100 MHz, 31P 162 MHz) spectrometer, with the chemical shifts (δ) indicated in ppm, and coupling constants (J) in Hz. The FTIR characterization of the dopants was done on a PerkinElmer FT-IR Spectrum BX Fourier Transform spectrometer, using KBr discs, and the characterization

Primary amine-catalyzed enantioselective 1,4-Michael addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones

• Pooja Goyal,
• Akhil K. Dubey,
• Raghunath Chowdhury and
• Amey Wadawale

Beilstein J. Org. Chem. 2024, 20, 1518–1526, doi:10.3762/bjoc.20.136

• ent-3aa-ent-3na, 1H, 13C NMR spectra of 3aa–na, 1H NMR of ent-3aa–ent-3na and their HPLC traces and single crystal data of ent-3ba. Acknowledgements The authors are thankful to Ms. Ketki Lele for her help in some preliminary experiments. Funding The authors thank the Department of Atomic Energy (DAE

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide

• Christopher Mairhofer,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1510–1517, doi:10.3762/bjoc.20.135

• Research Center “RERI uasb”. All NMR spectra were referenced on the solvent residual peak (CDCl3: δ = 7.26 ppm for 1H NMR, δ = 77.16 ppm for 13C NMR,19F NMR unreferenced). IR spectra were recorded on a Bruker Alpha II FTIR spectrometer with diamond ATR-module using the OPUS software package. HRMS spectra

• = 17.2 Hz, 1H), 2.99 (d, J = 17.2 Hz, 1H), 1.45 (s, 9H); 13C NMR (75 MHz, CDCl3, 298 K, δ/ppm) 198.1, 167.4, 152.3, 136.4, 133.3, 128.4, 126.5, 125.6, 84.6, 70.6, 38.6, 28.0; IR (neat, FT-ATR, 298 K, ν̃/cm−1): 2984, 2928, 2853, 2110, 1747, 1736, 1718, 1604, 1589, 1548, 1466, 1431, 1397, 1372, 1353, 1326

• , 1H), 7.48 (t, J = 7.5 Hz, 1H), 4.11 (d, J = 17.9 Hz, 1H), 3.99 (d, J = 17.9 Hz, 1H), 1.49 (s, 9H); 13C NMR (126 MHz, CDCl3, 298 K, δ/ppm) 188.4, 162.0, 150.1, 137.0, 132.9, 129.1, 126.5, 126.2, 96.7, 86.1, 37.5, 27.8; IR (neat, FT-ATR, 298 K, ν̃/cm−1): 2984, 2930, 2878, 2854, 1748, 1719, 1656, 1604

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• giving access to the acyclic α-amino acid-based amides 6 straightforwardly. Experimental General details 1H and 13C NMR spectra were recorded on a Bruker Avance III 300 MHz spectrometer with a broad band observe probe. All NMR spectra were referenced on the solvent residual peak (CDCl3: δ 7.26 ppm for 1H

• NMR and δ 77.16 ppm for 13C NMR). NMR data are reported as follows: chemical shift (δ ppm), multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet, dd = doublet of doublet), coupling constants (Hz), relative integration value. High-resolution mass spectra were obtained using a

• ), 3.52–3.16 (m, 4H), 1.15 (t, J = 7.1 Hz, 3H); 13C NMR (75 MHz, CDCl3, 298.0 K) δ/ppm = 177.4, 171.0, 160.3, 139.1, 133.8, 132.6, 130.5, 128.6, 128.0, 127.8, 127.3, 125.6, 118.1, 75.9, 60.9, 44.9, 39.3, 13.9; IR (neat): 3080, 3070, 2917, 1815, 1732, 1656, 1480, 1175, 1093, 1059, 1030, 974, 893, 694 cm−1