(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• monochloride (ICl). We found that olefins 1a and 1b reacts with ICl under the influence of sunlight to form previously unknown 2-chloro-3-iodo-1,1,1,4,4,4-hexafluorobutane (5, Scheme 4). Pure final product 5 was isolated by distillation at 112 °C in 85% yield. NMR analysis as in the case of bromo derivative 2

• distillation in 52% yield for 6a,b and 34% yield for 7a,b. NMR analysis showed the mixtures of (E)- and (Z)-isomers in both cases with the ratio E/Z = ≈4:5 for 6a,b and E/Z = ≈1:2 for 7a,b. The configuration of the isomers was determined by the 5JFFcis coupling constant in the 19F{H} NMR spectrum (ca. 0 Hz for

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

• Eiichi Kayahara,
• Yoshiyuki Mizuhata and
• Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

• host–guest complex consisting of neutral [10]CPP and [5]CPP, [10]CPP⊃[5]CPP [31]. While the 1H NMR analysis also supported the closed-shell electronic structure of both the host and the guest, neutral [10]CPP and [5]CPP2+, respectively, a partial CT from the host to the guest was suggested by the

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• during purification by silica gel chromatography. On the other hand, NMR analysis of the crude reaction mixtures may be misleading due to possible overlap of the signals of H-3eq belonging both to disaccharide and monosaccharide derivatives sometimes present in such glycosylation mixtures. At low

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• manner, ultimately affording 27 with 90% yield. The formation of intermediates 24, 25, and 26 was elucidated through 1H NMR analysis, of which 24 and 26 were successfully isolated and characterized. A comprehensive analysis of the [2 + 2] CA–RE reaction activation parameters via 1H NMR spectroscopy

• yield for the ring-formation process was modest at 5% (see Scheme 16) [121][122]. The macrocycle in 46 was observed to engage with the peptide segment in low-polarity solvents. In contrast, 1H NMR analysis suggested that the macrocycle disengaged from the peptide segment and relocated along the alkyl

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• result indicated that CmaG is a component of Cma PKS. From NMR analysis and high-resolution (HR)MS analysis ([M + H]+ ion at m/z = 222.0766, which corresponds to C11H12NO4+, calcd. 222.0761) of purified 6, the structure of 6 was determined as N-acetyl-3-aminocoumaric acid (Figures S9–S13 and Table S1 in

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• spectrum) [106], we never detected such a peak in 19F NMR spectra of the neat IL, analysed after reaction work-up, keeping it under vacuum to completely eliminate diethyl ether traces before NMR analysis. It should be mentioned that the solution was kept in the NMR tubes only for the time necessary to

• the 19F NMR analysis of BMIm-BF4 after anodic oxidation in a divided cell, which shows a peak at −147.3 ppm (besides the peak at −150.6 due to BF4−) (see Supporting Information File 1, Figure S1e), which is replaced by a peak at −144.0 ppm (referred to −150.6 ppm for BF4−) when the electrolysis is

• . Therefore, while confirming the presence of the adduct, we could not quantify it. The next choice was DBU (1,8-diazabicyclo[5,4,0]undec-7-ene). The DBU-BF3 adduct is reported to be very stable in water and in air and not subjected to hydrolysis [115]. The DBU solubility in BMIm-BF4 was confirmed by NMR

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• yields (ca. 80%). NMR analysis showed that compounds 4a and 4c required further purification. Thus, they were recrystallized from acetonitrile, which led to a non-negligible loss of materials, thereby leading to final yields in the 50–60% range. Synthesis of MIC·CS2 zwitterions The synthesis of 1,4

• under high vacuum. 1H NMR analysis revealed that a significant amount of starting material was still present in most cases. Moreover, unidentified byproducts were also detected in some instances. Products 6a and 6b could be isolated in pure form and satisfactory yields upon recrystallization from

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• porphyrins were detected in the mass spectra of some of the products. 1H NMR analysis of the synthesized hexaphyrins proved that the spectra were in consistence with [26]hexaphyrin aromaticity [29]. Several other metal triflates such as Zn(OTf)2, Gd(OTf)3, and Yb(OTf)3 were also tested as catalysts in the

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• the R2 group. The stereochemistry of products 10 and 11 was confirmed by X-ray crystal structure and the 1H NMR analysis of both the major and minor diastereomers [69]. The first cycloaddition gives adducts 12 and 12’ as a diastereomeric mixture. At the second cycloaddition, both major and minor

• symmetry. The stereochemistry of the products was confirmed by X-ray crystal structure and NMR analysis. The reaction mechanism shown in Scheme 11 suggests that a semi-stabilized AMY 16 generated from the reaction of glycine and arylaldehydes undergoes a [3 + 2] cycloaddition with 14a via the favorable

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

• spiroketals (1 and 2) with a tetrasaccharide moiety. For terpenoid glycosides, the 1H NMR spectrum becomes more complex as the number of sugar residues and their lengths increase, which complicates 2D NMR analysis. In such cases, commonly used TOCSY measurements can be supplemented by H2BC and HSQC-TOCSY

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• -substituted triazole 3’a (entry 1, Table 1), in 21% yield, using NiCl2(PCy3)2 as a catalyst and K3PO4 as a base. A methyl handle on the gem-difluoroalkene 1 was used to aid in 1H NMR analysis. The gem-difluoroalkenes were synthesized in one step using sodium 2-chloro-2,2-difluoroacetate and triphenylphosphine

• chemistry applications. In the reaction with piperidine, we observed unreacted organic azide 2b by TLC and 1H NMR analyses. Based on the 1H NMR analysis, 0.4 equiv of 2b had reacted to form the product, 0.9 equiv of 2b had decomposed to form aniline, and the remaining 0.2 equiv of 2b was unreacted

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• =CHC(=O)Me] with arenes in Brønsted superacid TfOH (triflic acid, CF3SO3H) furnishes 3-methyl-1-trichloromethylindenes (Scheme 1a) [11]. Based on NMR analysis in TfOH and theoretical DFT calculations, it has been found that the reaction proceeds through an intermediate formation of the O-protonated

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

• publication was misattributed and should be revised as shown in Figure 1. The error happened due to insufficient in-depth 2D NMR analysis. We reanalyzed the 2D NMR data of compound 1 in detail and finally determined the correct structure as shown in Figure 1. The revised structure of 1 is supported by the

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• %) were added to a solution of 1 (10 mol %) in 2 mL of solvent (0.25 M) and allowed to stir for 48 hours at room temperature. Yields of isolated compounds are given. Diastereomeric ratio (dr) determined by 1H NMR analysis. Enatiomeric excess (ee) determined by chiral HPLC analysis. Original triple

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

• transformation of the dtbbpy ligand to a monoanionic ligand. Extensive NMR analysis confirmed that upon the formation of [Ir1]0 via SET from Et3N to *[Ir1]+, partial saturation of the dtbbpy ligand generates [Ir2]0 and initiates the second catalytic cycle (Figure 17A). Upon excitation with blue light, *[Ir2]0

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

• (Table 1) spectra indicate 15 carbons, including one methyl, eight methylenes (one sp2), one methine, and four nonprotonated carbons (including three sp2 and one sp3). The planar structure of 1 was mainly constructed by 2D NMR analysis. First, the 1H,1H-COSY spectrum (Figure 2) displays the correlations

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

• was not accomplished either by NMR analysis or chromatography. Conclusion In conclusion, we have developed an SO2F2-mediated ring-opening cross-coupling reaction of cyclobutanone oxime derivatives with alkenes for the synthesis of a class of novel elongated nitriles. The newly constructed δ-olefin

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

• initiated when the system reaches a steady state, based on the dispersion curves given by the apparatus. After reaching the steady state an aliquot of the product was taken for 1H NMR analysis using p-dinitrobenzene as an internal standard. 3-(2-(Triethoxysilyl)ethyl)furan-2-carbaldehyde (2a) The reaction

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

• found to shift to lower ppm values because the Hα nuclei have been affected by higher electron density caused by the formation of the halogen-bonded complex between 2a and DABCO. To confirm that the shift of Hα was indeed produced by a halogen-bonding interaction, 19F NMR analysis of compound 2d, which

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

• , entry 10). Instead of small amounts of liquid, here, deprotonation leads to the formation of dihydrogen. Hence, another gastight mill was utilized for this approach. Unfortunately, a successful synthesis of 5 directly from 3 was not possible under these conditions: NMR analysis of the resulting mixture

• total time of four hours. After ball milling, an off-white powder was obtained which gave complex 5 in very good yield of 91% after extraction with CH2Cl2 and filtration. NMR analysis of 5 matched previously reported data [48][49] and showed no side products. It has to be mentioned that complex 5

Asymmetric synthesis of a stereopentade fragment toward latrunculins

• Benjamin Joyeux,
• Antoine Gamet,
• Nicolas Casaretto and
• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32

• ]2 (2.5 mol %), (S)-SEGPHOS (5 mol %), 3-nitrobenzoic acid (10 mol %), Cs2CO3 (20 mol %) in THF at 100 °C for 24 hours – we obtained homoallylic alcohol 12 in a good 86% yield, with a diastereomeric ratio (dr) of 93:7 deduced from the NMR analysis of the methyl substituent signals in CD3OD (NMR

• secured by the NMR analysis of Mosher's esters made from (R)-(+)- and (S)-(−)-α-methoxy-α-trifluoromethylphenylacetic acid (MTPA) (see Supporting Information File 1) [23][24][25], confirming the installation of the C-11 stereocenter of latrunculins. The next steps consisted in the functionalization of 12

• relied on the comparative NMR analysis of Mosher's esters [23]. Despite clear 1H NMR spectra, irregular values of ΔδS–R precluded the unambiguous determination of the C-15 stereocenter [24]. These difficulties were attributed to the hindered character of this secondary alcohol, substituted by the

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• -oxazolinium triflate (EtOxMeOTf) was synthesized. The 1H NMR analysis showed all expected resonances and in particular the signals at 4.98 ppm and 4.29 ppm, attributed to the typical methylene protons in the oxazolinium ring (Figure S2, Supporting Information File 1). Unfortunately, regarding the

• resulting molar mass after initiation with EtOxMeOTf is closer to what is expected from [M]0/[I]0 ratio (Figure 6b, blue) and Ð remained below 1.2. 1H NMR analysis of the final product after precipitation and freeze-drying confirmed the presence of signals attributed to PEtOx, whereas the additional signals

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• underwent nucleophilic attack, leading the formation of the three desired compounds. The diastereomer 14 showed the same linear retention index I = 1596 and the same mass spectrum as A. After detailed NMR analysis, the relative configuration of the natural product could be determined. The most stable

A novel spirocyclic scaffold accessed via tandem Claisen rearrangement/intramolecular oxa-Michael addition

• Anastasia Vepreva,
• Alexander Yanovich,
• Dmitry Dar’in,
• Grigory Kantin,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1649–1655, doi:10.3762/bjoc.18.177

• reactivity and the Claisen rearrangement step was performed at a higher (150 °C) temperature. Notable was our inability to involve o-methoxy- (5n) and (p-methoxy)phenoxy (5m) substrates in the two-step synthesis of the respective spirocycles 7. In both cases, 1H NMR analysis of the reaction mixture indicated

A novel bis-triazole scaffold accessed via two tandem [3 + 2] cycloaddition events including an uncatalyzed, room temperature azide–alkyne click reaction

• Ksenia Malkova,
• Andrey Bubyrev,
• Vasilisa Krivovicheva,
• Dmitry Dar’in,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1636–1641, doi:10.3762/bjoc.18.175

• . Stronger electron-withdrawing cyano group (3i) lowered the product yields to 20% due to low conversion of 3i. Introducing even a stronger electron acceptor, a nitro group (aldehyde 3j), led to only a trace amount of the respective product detected by 1H NMR analysis of the crude reaction mixture. Likewise

• intermediate before the click reaction was established by 1H NMR analysis of the reaction mixture). However, the product of this two-step, one-pot reaction (19) was isolated in respectable 61% yield. The structure of compound 19 was confirmed by the single-crystal X-ray analysis which demonstrated that the