Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• effects, too, e.g., modulating lipophilicity [44][113][114][115], enabling target-binding interactions to be elucidated [116][117], or providing the opportunity for 19F and 18F imaging. Other reviews have covered many of these aspects [118][119], but here we will focus exclusively on the conformational

Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex

• Maurizio Iannuzzi,
• Thomas Hohmann,
• Michael Dyrks,
• Kilian Haoues,
• Katarzyna Salamon-Krokosz and
• Beate Koksch

Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52

• Schlenk vessels at a Schlenk unit/oil pump vacuum under nitrogen atmosphere. The stated reaction temperatures are the respective values of the silicone oil heating bath. All reactions were stirred with an electric magnetic stirrer. 1H, 13C, and 19F NMR spectra were measured at room temperature with a JEOL

• -column chromatography (n-Pen/EtOAc, 10:1). The product 9 was obtained as a colorless oil (2.99 g, 10.6 mmol, 27%). 1H NMR (600 MHz, CDCl3) δ 7.81–7.76 (m, 2H), 7.39–7.34 (m, 2H), 4.16 (dd, J = 10.3, 5.3 Hz, 1H), 3.97 (dd, J = 10.3, 6.8 Hz, 1H), 2.62–2.54 (m, 1H), 2.46 (s, 3H), 1.23–1.15 (m, 3H) ppm; 19F

• for 24 h. The crude product was purified by vacuum distillation (4 × 10−2 mbar). The product 10 was obtained as colorless liquid (4.41 g, 18.5 mmol, 70%). 1H NMR (600 MHz, CDCl3) δ 3.44 (dd, J = 10.3, 3.5 Hz, 1H), 2.97 (t, J = 10.1 Hz, 1H), 2.53–2.43 (m, 1H), 1.29 (d, J = 6.9 Hz, 3H) ppm; 19F NMR (565

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• Information File 1). In the 19F NMR spectra of 9,10-ANTH(BnF)2 (Figure 1) and 9-ANTH(BnF) (Figure S4 in Supporting Information File 1), only four resonances in a 2:2:1:2 ratio were observed, commensurate with the previously reported data for compounds bearing BnF groups [18][29]. The 19F resonances of the CF2

• photoirradiated 9,10-ANTH(BnF)2 solution contained only resonances for the starting material (20%) and for a single presumed photoproduct (80%) which retained the symmetry of 9,10-ANTH(BnF)2 (see Supporting Information File 1, Figures S7 and S9 (19F NMR)). An HPLC analysis of the photoirradiated ANTH solution

• ) were used as received. Instrumentation 19F (376 MHz) and 1H (400 MHz) NMR spectra were recorded using a Varian INOVA 400 instrument with a trace amount of C8H4F6 (δ(19F) = −66.35 ppm) added as the internal standard. UV–vis spectra were recorded using a Cary 500 UV–VIS–NIR. Emission spectra of the LED

Synthesis of the aggregation pheromone of Tribolium castaneum

• Biyu An,
• Xueyang Wang,
• Ao Jiao,
• Qinghua Bian and
• Jiangchun Zhong

Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38

• )-10. Synthesis of the aggregation pheromone of Tribolium castaneum. Supporting Information Supporting Information File 6: General information, synthesis of compounds 1–12, research on the optical purity of chiral alcohols (R)- and (S)-4, and copies of 1H, 13C and 19F NMR spectra. Funding This

Electrochemical synthesis of cyclic biaryl λ³-bromanes from 2,2’-dibromobiphenyls

• Andrejs Savkins and
• Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

• hypobromite D. The latter decomposes into bromide and hexafluoroacetone, with the latter observed by 19F NMR [25]. Assuming that intermediate B is sufficiently stable to leave the diffusion layer and undergoes disproportionation to the species C in the bulk electrolyte provides a reasonable explanation for

Nickel-catalyzed cross-coupling of 2-fluorobenzofurans with arylboronic acids via aromatic C–F bond activation

• Takeshi Fujita,
• Haruna Yabuki,
• Ryutaro Morioka,
• Kohei Fuchibe and
• Junji Ichikawa

Beilstein J. Org. Chem. 2025, 21, 146–154, doi:10.3762/bjoc.21.8

• , excluding boronic acid 2a (Scheme 6). The reaction was monitored using 19F and 31P NMR spectroscopy. The 19F NMR analysis showed that 79% of 1b remained and revealed a new broad double doublet peak at 55.0 ppm (JFP = 53, 42 Hz) relative to internal C6F6 (δ = 0.0 ppm). The 31P NMR spectrum depicted broad

• important in pharmaceuticals and agrochemicals [41][42][43][44][45][46][47], we expect that this method will provide a novel and efficient approach for producing these valuable compounds. Experimental General: 1H NMR, 13C NMR, 19F NMR, and 31P NMR were recorded on a Bruker Avance 500 or a JEOL ECS-400

• spectrometer. Chemical shift values are given in ppm relative to internal Me4Si (for 1H NMR: δ = 0.00 ppm), CDCl3 (for 13C NMR: δ = 77.0 ppm), C6F6 (for 19F NMR: δ = 0.0 ppm), and H3PO4 (for 31P NMR: δ = 0.0 ppm). IR spectra were recorded on a Horiba FT-730 spectrometer. Mass spectra were measured on a JEOL

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

• discover more than ten copolymer compositions of promising 19F MRI agents that outperformed state-of-the-art materials. A rapid generation of copolymer libraries was achieved by forming a droplet flow in an automated HTE flow setup [52]. This approach not only assists in overcoming viscosity challenges in

Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives

• Shuxian Qiu,
• Duan Dong,
• Jiahui Li,
• Huiting Wen,
• Jinpeng Li,
• Yu Yang,
• Shengxian Zhai and
• Xingyuan Gao

Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274

• available 2-bromo-4-fluoro-1-nitrobenzene, featuring a noble-metal-free system, mild reaction conditions, and a good yield, especially for the final Cs2CO3-facilitated nucleophilic substitution (77–91% yield). The characterization data obtained from IR and NMR spectroscopy (1H, 13C, 19F, and 31P) as well as

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

• Yang Chen,
• Jiao He,
• Hang Lin,
• Hai-Feng Wang,
• Ping Hu,
• Bi-Qin Wang,
• Ke-Qing Zhao and
• Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

• ) was synthesized via consecutive Suzuki coupling and Scholl reaction in a total yield of 77%. The synthesis, molecular structures, nomenclature, and synthetic yields of all compounds are shown in general Scheme 1. All prepared molecules were fully characterized by NMR (1H, 19F and 13C), HRMS, and CHN

• positions. The similarity of the 19F NMR spectra of F and alkoxy-substituted derivatives, Fn, showing 6 single peaks, corresponding to the 8 different fluorine atoms at almost identical positions (Figures S8–S14 and S21 in Supporting Information File 1), confirms that the pattern of the annulation reaction

• '-hexafluoro-6,6',7,7',10,10',11,11'-octakisalkoxy-2,2'-bitriphenylene dimers (G55, G66 and G48). Mesophases’ parameters. Supporting Information Synthesis (Schemes S1–S3) and characterization, 1H, 13C, and 19F NMR (Figures S1–S21), HRMS (Figures S22–S32), EA, single crystal X-ray structures (Figures S33, S34

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• 19F,1H NOE experiments of compound 8f did not show any specific correlation between fluorine atoms and the protons of the amino acids (see Supporting Information File 1). Finally, the low chemical shifts of the amide and carbamate protons (6.4 ppm for NH of valine and 5.5 ppm for the NH of

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• the equivalents of [1.1.1]propellane (1) relative to SF5Cl and evaluating the impact on selectivity (Table 1). A 0.1 M solution of SF5Cl in n-pentane was added to a 0.8 M solution of 1 in Et2O at room temperature, and the mixture was stirred for 3 hours prior to 19F NMR analysis. Upon increasing from

• be accounted for in the formation of these two products alone by 19F NMR. To the best of our knowledge, this is an exceptionally rare instance whereby oligomerization of 1 appears to be stunted beyond formation of the [2]staffane; only trace yields of putative higher-order staffanes (n > 2) were

• detected in the crude reaction mixture. Remarkably, using 20 equiv of 1, the observed 4:2 product ratio improved to 1:3, with 2 formed in 72% yield. In an even more extreme case, the [2]staffane still remained the major product formed in 66% yield when using 50 equiv of 1 (19F NMR signals of presumed

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• (cis/trans) determined by 19F NMR analysis. Kitamura’s synthesis of 3-fluoropyrrolidines. Values in parentheses represent the cis:trans ratio. Jacobsen’s enantio- and diastereoselective protocol for the synthesis of syn-β-fluoroaziridines 15. Different HVI reagents lead to different

• unsaturated carboxylic acids. Yield of isolated product within parentheses. Synthesis of fluorinated tetrahydrofurans and butyrolactone. Synthesis of fluorinated oxazolines 32. aReaction time increased to 40 hours. Yields refer to isolated values whilst NMR yields are given in parentheses (19F NMR using ethyl

Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins

• Mike Brockmann,
• Jonas Lobbel,
• Lara Unterriker and
• Rainer Herges

Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248

• Information File 42: Experimental procedures, characterization data of all products, and copies of 1H, 13C, and 19F NMR spectra. Acknowledgements We thank Dr. Claus Bier for the help with the HPLC–ESIMS measurements.

gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

• Monika Bilska-Markowska,
• Marcin Kaźmierczak,
• Wojciech Jankowski and
• Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

• characteristic (Table 1, entry 7). A slightly higher reactivity was achieved when the BF3·(OEt2) was used instead of TiCl4 (Table 1, entry 8) [28]. The reactions were monitored by 19F NMR of the crude mixtures. The full conversion was reached by applying exclusively n-BuLi, but the formed product was not the

• products. These highly stable compounds were isolated after purification on silica gel in good yields (Scheme 2) and characterized by spectroscopic methods. The reaction proceeded with very high Z-stereoselectivity (Scheme 2, compounds 9a–d). In the 19F NMR spectra of crude mixtures, only trace amounts of

• E-isomer of products 9 were identified. The fluorine atom signals of 9a–d were located at approximately −112 ppm (triplets, J ≈ 27 Hz, Fβ) and at −155 to −159 ppm (multiplets, Fα). The stereochemistry was determined by 19F{1H} NMR spectroscopy. The observed coupling constants J ≈ 2 Hz between

C–H Trifluoromethylthiolation of aldehyde hydrazones

• Victor Levet,
• Balu Ramesh,
• Congyang Wang and
• Tatiana Besset

Beilstein J. Org. Chem. 2024, 20, 2883–2890, doi:10.3762/bjoc.20.242

• expected product was detected (Scheme 4C). Having in mind that in the presence of an oxidant, the SCF3 dimer (SCF3)2 might be generated, an additional test was realized. In the presence of NCS in THF, AgSCF3 was converted into the corresponding dimer in 5 min (monitored by 19F NMR). Then, the reaction was

• room temperature. α,α,α-Trifluoroacetophenone (42 μL, 0.3 mmol, 1.0 equiv) was added as an internal standard for determining the 19F NMR yield. The mixture was then filtered on a pad of celite and rinsed with CH2Cl2. The solution was then washed with brine twice (20 mL) and the organic layers were

Mechanochemical difluoromethylations of ketones

• Jinbo Ke,
• Pit van Bonn and
• Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

• scale. Method A: 2 (2.0 equiv), KFHF (4.0 equiv), CH2Cl2 (0.2 mL), H2O (0.2 mL), rt, 10 h; Method B: 2 (2.0 equiv), KOAc (4.0 equiv), CH2Cl2 (0.2 mL), H2O (0.2 mL), rt, 10 h. The yields were determined by 19F NMR spectroscopy using trifluoromethoxybenzene as the internal standard. Scope of ketones. The

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

• Yuta Kabumoto,
• Eiichiro Yoshimoto,
• Bing Xiaohuan,
• Masato Morita,
• Motohiro Yasui,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

• scope for the present [1,3]-proton shift reaction. aYields are determined by 19F NMR spectroscopy. Values in parentheses show isolated yields. Enantiomeric excesses are deteremined by HPLC equipped with DAICEL CHIRALPAK AD-H. bCarried our at 50 °C in the [1,3]-proton shift reaction step. Proposed

• reaction mechanism. Investigation of the reaction conditions. Supporting Information Supporting Information File 3: Full experimental details, 1H, 13C, 19F NMR spectra of 16a–g and 23a–g, and HPLC charts of racemic as well as chiral compounds 23a–g. Supporting Information File 4: Crystallographic

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• laboratory, and the results will be reported in due course. Experimental General methods 1H, 13C and 19F NMR spectra were recorded on a JEOL 400 spectrometer (at 400 MHz, 101 MHz and 376 MHz, respectively). Unless otherwise stated, NMR spectra were recorded using residual solvent as the internal standard; 1H

• without further purification. Graphene oxide (GO) was purchased from Graphenea. All products were characterized by 1H,13C, 19F (when fluorine is present) NMR, IR and HRMS. General procedure for the one-pot synthesis of spiro[indole-isoquinoline] 3a: A solution of N-phenyltetrahydroisoquinoline (1 equiv

• studies; description of photochemical equipment; characterization data of compounds (1H, 13C and 19F NMR spectra, IR and UV–vis spectra). Acknowledgements The University of Genova is kindly acknowledged for the contribution to the acquisition of an NMR instrument (D.R. 3404 19/7/2018). We thank Mr

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• , bathochromically shifted absorption and emission spectra with elevated extinction coefficients and quantum yields up to 71%. Further studies will be directed to the synthesis to polycyclic, π-conjugated uracil derivatives. Experimental General information Nuclear magnetic resonance spectra (1H/13C/19F NMR) were

• acetate 3:2)); mp 187–189 °C; IR (ATR) ν̃: 1708 (s), 1654 (vs), 1574 (s), 1514 (s), 1506 (s), 1446 (s), 1423 (s), 1232 (s), 1158 (s) cm−1; 1H NMR (500 MHz, chloroform-d) δ 7.48–7.44 (m, 2H), 7.26–7.22 (m, 2H), 7.15–7.10 (m, 2H), 7.06–7.02 (m, 2H), 3.70 (s, 3H), 3.44 (s, 3H); 19F NMR (471 MHz, chloroform-d

• , 3H), 6.92–6.84 (m, 2H), 3.75 (s, 3H), 3.59 (s, 3H), 3.09 (s, 6H); 19F NMR (282 MHz, chloroform-d) δ −62.2; 13C {1H} NMR (75 MHz, chloroform-d) δ 162.3, 151.4, 150.9, 150.2, 142.6, 134.4, 130.8, 127.7, 127.3, 127.1 (q, J = 32.6 Hz), 126.0, 124.9 (q, J = 2.8 Hz), 124.7 (q, J = 4.7 Hz), 124.4 (q, J

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• and 3 as new fluorine-containing building blocks. Experimental General information 1H NMR, 19F NMR, and 13C NMR spectra were recorded on JEOL ECZ 400S spectrometers. Chemical shifts of 1H NMR are reported in ppm from tetramethylsilane (TMS) as an internal standard. Chemical shifts of 13C NMR are

• reported in ppm from the center line of the triplet at 77.16 ppm for deuteriochloroform. Chemical shifts of 19F NMR are reported in ppm from CFCl3 as an internal standard. All data are reported as follows: chemical shifts, multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, sep = septet, br

• ), 124.8, 127.3, 127.4, 127.9 (d, J = 3.2 Hz), 128.2 (d, J = 5.5 Hz), 128.5 (d, J = 7.2 Hz), 128.6 (d, J = 11.8 Hz), 128.9, 130.1 (d, J = 4.2 Hz), 132.46 (d, J = 5.7 Hz), 132.52, 141.3, 151.2 (d, J = 286.1 Hz), 151.5 (d, J = 287.3 Hz), 154.3 (d, J = 3.4 Hz), 154.4 (d, J = 3.3 Hz); 19F NMR (376 MHz, CDCl3

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

• assemblies, 2+-BF4− was further treated with NaPF6, LiB(C6F5)4, and NaPCCp for the ion-pair metathesis to afford ion pairs 2+-X− (X− = PF6−, B(C6F5)4−, and PCCp−) in 44–68% yields. The obtained ion pairs were characterized using 1H, 13C, and 19F nuclear magnetic resonance (NMR) and matrix-assisted laser

• ) 142.15, 140.66, 138.90, 136.12, 134.80, 130.88, 130.80, 110.29, 106.31, 17.63; 19F NMR (564 MHz, CDCl3, 20 °C) δ (ppm) −157.91 (s, 10BF4−), −157.96 (s, 11BF4−); UV–vis (CH3CN) λmax, nm (ε, 105 M−1 cm−1): 272 (1.28), 337 (0.06), 349 (0.09), 524 (0.21); MALDI–TOF MS (m/z) (% intensity): (positive) 594.3

• , 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

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• order to decipher the key physical properties of complex pyran inter-halides, we performed 19F NMR analysis of halogenated talose analogues 12–15 (Figure 2). First, all analogues adopt standard 4C1-like conformations. Comparison of the vicinal and geminal coupling constants for each organohalogen

• suggests that there is little change in the conformations (although there is an increasing chair distortion for larger halogens, see below). Because F3 is adjacent to the C4 halogen, 19F resonance of F3 occurs at lower field than F2 for analogues 13–15. There is a strong increase in chemical shift of F3

• −200.55 ppm for 15. Talopyranose analogues 12–15 incorporate a 2,3-cis, 3,4-cis relationship for the halogens. We previously prepared a small set of trihalogenated allopyranose analogues that also included the 2,3-cis, 3,4-cis relationship for the halogens (Figure 1a) [23]. 19F NMR analysis of halogenated

Phenylseleno trifluoromethoxylation of alkenes

• Clément Delobel,
• Armen Panossian,
• Gilles Hanquet,
• Frédéric R. Leroux,
• Fabien Toulgoat and
• Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

• stirred at room temperature for 2.5 h (unless otherwise stated). Note that a yellowish precipitate is formed during the reaction for high yielding substrates. The reaction is monitored by 19F NMR (PhCF3 as internal standard). At the end of the reaction, the content of the vial is transferred to a

• by chromatography. Examples of trifluoromethoxylated drugs. Proposed mechanism of the reaction and 19F NMR of the DDPYOCF3/PhSeBr mixture. Phenylseleno trifluoromethoxylation of various alkenes. Yields determined by 19F NMR spectroscopy with PhCF3 as internal standard (in parentheses isolated yields

• ). a24 h. b48 h. Degradation of 2a under acidic conditions. Radical deselenylation of 2. Yields determined by 19F NMR spectroscopy with PhCF3 as internal standard (in parentheses isolated yields). Reaction of 1a with PhSeX and DDPyOCF3.a Supporting Information Supporting Information File 116: Additional

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

• during the lactone-forming process. Their close structural resemblance led to a significant peak overlap both in the 1H and 19F NMR spectra which made it difficult to obtain their exact ratio and thus, the combined 19F NMR yields were shown in Table 4. Separation of these two compounds was eventually

• the complex mixture after mixing 2b with t-BuOK and nitroacetate in DMSO at 80 °C, the unexpected compound 2,3-dihydroxybutyrate anti-10a was isolated as a single isomer. Its production was also detected by 19F NMR from the reaction mixture when nitromethane (16%) and ethyl (diethylphosphono)acetate

• 49.4 (q, J = 2.5 Hz), 52.7 (q, J = 42.2 Hz), 68.0, 121.4 (q, J = 276.0 Hz), 128.5, 128.7, 128.8, 134.3, 165.6; 19F NMR (282.65 MHz, CDCl3) δ −75.12 (d, J = 4.5 Hz); IR (neat) ν: 3944, 3689, 3054, 2987, 2685, 2306, 1756, 1456, 1422, 1382, 1341, 1265, 1169, 1089, 988, 929, 896, 664 cm−1; Anal. calcd for

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

• Dominik L. Reinhard,
• Anna Schmidt,
• Marc Sons,
• Julian Wolf,
• Elric Engelage and
• Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

• , indicating that the activated gold complex is the catalytically active species. Furthermore, stability measurements (1H and 19F NMR) of 1:1 mixtures of the gold complex and the XB donors were performed in order to investigate the stability of the cationic iodonium structures towards the gold complex [28

• ]. For all catalyst systems, decomposition of the −BArF24 anion was observed via 1H and 19F NMR spectroscopy, which is known to happen in the presence of activated gold complexes [29]. The stability of the DAI cations was checked with 1H NMR: the characteristic doublets belonging to the respective

• iodonium structures 1+, 2+, 3+, and 7+ were found to be constant (see Supporting Information File 1). The signals of the iodoxinium cation 4+ were overlapping with signals of the anion. However, the stability of 4+ (as well as of 2+) could be confirmed by 19F NMR measurements: no decomposition of the