Synthesis of new fluorescent molecules having an aggregation-induced emission property derived from 4-fluoroisoxazoles

• Kazuyuki Sato,
• Akira Kawasaki,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2020, 16, 1411–1417, doi:10.3762/bjoc.16.117

• fluorescence data for 4-fluoroisoxazoles 3b and 3c, and non-fluorinated compound 2ca. Optical properties of BKIs and F-BKIs. Supporting Information Supporting Information File 68: General procedures and analytical data, including copies of 1H NMR, 13C NMR and 19F NMR spectra. Acknowledgements We wish to

Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow

• Alexander V. Nyuchev,
• Ting Wan,
• Borja Cendón,
• Carlo Sambiagio,
• Job J. C. Struijs,
• Michelle Ho,
• Moisés Gulías,
• Ying Wang and
• Timothy Noël

Beilstein J. Org. Chem. 2020, 16, 1305–1312, doi:10.3762/bjoc.16.111

• trifluoromethoxylation methodologies. Effect of KH2PO4 – other substrates. a Conditions as for entry 15 (Table 2), 1 h residence time; b conditions as for entry 14 (Table 2), 18 h reaction time; c 0.5 equiv KH2PO4, CH3CN/CH2Cl2 1:1; d 2 equiv KH2PO4. 19F NMR yields are reported. A) Properties and B) synthesis of CF3O

• -bearing arenes; C) trifluoromethoxylation using the “second” Ngai reagent. Optimization of residence time. 19F NMR yields are reported. Scope of photoredox trifluoromethoxylation in continuous-flow. In case of different products, the major isomer is shown. The position of the CF3O group in the minor

• isomer is marked with a star. 19F NMR yields are reported. a CH3CN/CH2Cl2 3:2, 0.08 M; b CH3CN/CH2Cl2 1:1, 0.05 M; c CH3CN/CH2Cl2 5:3, 0.05 M; d CH3CN/CH2Cl2 3:2, 0.02 M; e CH3CN/CH2Cl2 5:4, 0.057 M. Reaction optimization under flow conditions. Influence of bases on the photoredox trifluoromethoxylation

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

• Shigeyuki Yamada,
• Takuya Higashida,
• Yizhou Wang,
• Masato Morita,
• Takuya Hosokai,
• Kaveendra Maduwantha,
• Kaveenga Rasika Koswattage and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

• . Interestingly, stirring 1a in DMSO solution in the presence of 30 mol % of PdCl2 at 140 °C for 17 h produced two products (56% yield for the more polar product and 37% yield for the less polar product) after purification with column chromatography. Spectroscopic analyses (i.e., 1H, 19F, and 13C nuclear magnetic

• procedures for the synthesis and characterization of fluorinated benzils 2a and 2b, fluorinated bisbenzils 3a and 3b, and nonfluorinated bisbenzil 3c. 1H, 13C, and 19F NMR spectra of 2a, 2b, and 3a–c. Cartesian coordinates of the optimized geometries of 1a, 1c, 2a, and 3a obtained from DFT calculations

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

• Esteban P. Urriolabeitia,
• Pablo Sánchez,
• Alexandra Pop,
• Cristian Silvestru,
• Eduardo Laga,
• Ana I. Jiménez and
• Carlos Cativiela

Beilstein J. Org. Chem. 2020, 16, 1111–1123, doi:10.3762/bjoc.16.98

• isomers, the transoid (in which the two cyclopalladated oxazolones are in an anti arrangement) and the cisoid (syn arrangement). The presence of the two isomers in 3 is clear from the observation of two sets of signals due to the CF3CO2– ligand in the 19F NMR spectra. The major isomer shows one singlet

• stereoisomer, despite the presence of two isomers in the starting materials 3. The 1H NMR and 13C NMR spectra clearly showed the chemical equivalence of the two ortho-palladated fragments, while 19F NMR spectra showed the equivalence of the bridging trifluoroacetate ligands. This means that only the transoid

• universal attenuated total reflectance (UATR) accessory made of thallium bromide-iodide crystals (KRS-5). The 1H, 13C{1H} and 19F NMR spectra were recorded on Bruker Avance-300 and -400 spectrometers (δ in ppm; J in Hz). All spectra were recorded at room temperature in solution, using CDCl3 as deuterated

Copper-based fluorinated reagents for the synthesis of CF₂R-containing molecules (R ≠ F)

• Louise Ruyet and
• Tatiana Besset

Beilstein J. Org. Chem. 2020, 16, 1051–1065, doi:10.3762/bjoc.16.92

• substrates. Based on 19F NMR studies, the authors suggested the following mechanism: first the in situ generation of a CuCF2H complex from TMSCF2H in equilibrium with the corresponding cuprate (Cu(CF2H)2−) occurred followed by the reaction with terminal alkynes under basic conditions. The resulting

• either from the pre-isolated (K(DMF))Cu(Ot-Bu)2 or in situ from CuCl, t-BuOK in DMF in a nearly quantitative yield. The copper reagent was used for the pentafluoroethylation of a panel of (hetero)aryl iodides and bromides (up to 99% 19F NMR yield) and its synthetic utility was further demonstrated with

• , pyrimidine and quinolone derivatives, for instance, when the PhenCuCF2CF3 complex was used as the pentafluoroethyl source (24 examples, up to 99% 19F NMR yield and up to 93% isolated yield, Scheme 15). Note that a complete mechanistic study was recently reported to explain the reactivity of this well

Towards triptycene functionalization and triptycene-linked porphyrin arrays

• Gemma M. Locke,
• Keith J. Flanagan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

• , triptycene-H), 7.03 (d, 4H, pyrrole-H), 6.62 ppm (s, 4H, pyrrole-H); 13C NMR (151 MHz, CDCl3) δ 146.4, 144.7, 143.5, 135.0, 134.3, 132.3, 131.6, 130.9, 126.3, 126.2, 125.6, 122.5, 119.0, 92.3, 86.4, 29.8; 11B NMR (128 MHz, CDCl3) δ 0.32 (t, J = 28.7 Hz); 19F NMR (377 MHz, CDCl3) δ −145.04 (dd, J = 57.5, 28.7

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

• Marcin Kaźmierczak and
• Henryk Koroniak

Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69

• worse results in each case. We assume it is associated with a much greater reactivity of this reagent in relation to PyFluor. The mechanism of the PyFluor-mediated deoxyfluorination of the α-hydroxy-β-aminophosphonates 5 was previously proposed. Based on spectroscopic studies (19F,1H-HOESY, 1H,1H-NOESY

• with potential biological activity. Experimental General methods 1H NMR, 13C NMR, 19F NMR and 31P NMR spectra were obtained on a Bruker ASCEND 400 (400 MHz) and a Bruker ASCEND 600 (600 MHz) spectrometer. All 2D spectra were recorded on a Bruker ASCEND 600 (600 MHz) spectrometer. 1H NMR chemical shifts

• were expressed in parts per million downfield from tetramethylsilane (TMS) as an internal standard (δ = 0) in CDCl3 or CD3CN. 13C NMR chemical shifts were expressed in parts per million downfield from CDCl3 (δ = 77.0) or CD3CN (δ = 1.39) as internal standards. 19F NMR chemical shifts were expressed in

Cascade trifluoromethylthiolation and cyclization of N-[(3-aryl)propioloyl]indoles

• Ming-Xi Bi,
• Shuai Liu,
• Yangen Huang,
• Xiu-Hua Xu and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2020, 16, 657–662, doi:10.3762/bjoc.16.62

• ), which suggested that the radical process was probably involved in these transformations. Notably, no TEMPO-trapped product was detected by 19F NMR spectra of the crude reaction mixtures. On the basis of these results and literature studies [21][23][42][43][44][45][46][47], a plausible reaction mechanism

Asymmetric synthesis of CF₂-functionalized aziridines by combined strong Brønsted acid catalysis

• Xing-Fa Tan,
• Fa-Guang Zhang and
• Jun-An Ma

Beilstein J. Org. Chem. 2020, 16, 638–644, doi:10.3762/bjoc.16.60

• ) were added and the mixture was reacted at rt for 24 hours unless otherwise annotated. The yields are those of isolated products, and the dr was determined by 19F NMR analysis of the crude mixture. The results in parentheses are those of isolated products after the dissolution–filtration process: The

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

• Takahide Shimada,
• Shigeki Mori,
• Masatoshi Ishida and
• Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

• of TIPS-ethynyl-substituted BODIPY derivatives 3–6 were characterized by 1H and 19F NMR spectroscopy, high-resolution mass spectrometry, and X-ray crystallographic analysis. The solid-state structures of the diethynyl-substituted BODIPYs were unambiguously elucidated by X-ray diffraction analysis (3a

Regio- and stereoselective synthesis of new ensembles of diversely functionalized 1,3-thiaselenol-2-ylmethyl selenides by a double rearrangement reaction

• Svetlana V. Amosova,
• Andrey A. Filippov,
• Nataliya A. Makhaeva,
• Alexander I. Albanov and
• Vladimir A. Potapov

Beilstein J. Org. Chem. 2020, 16, 515–523, doi:10.3762/bjoc.16.47

• and 8 were proved by 1H, 13C, 15N, 19F and 77Se NMR and mass spectrometry. The composition of the products was confirmed by elemental analysis. Molecular ions of the synthesized compounds were observed in their mass spectra. Two doublets of the olefinic protons of the SCH=CHSe group with 3J = 6.3–6.6

• Information Supporting Information File 234: Experimental section and 1H, 13C, 15N, 19F and 77Se NMR spectra of all synthesized compounds. Acknowledgements The authors thank Baikal Analytical Center SB RAS for providing the instrumental equipment for structural investigations.

Aerobic synthesis of N-sulfonylamidines mediated by N-heterocyclic carbene copper(I) catalysts

• Faïma Lazreg,
• Marie Vasseur,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2020, 16, 482–491, doi:10.3762/bjoc.16.43

• (Triaz)), 28.8 (s, 2 CHCH3 (Triaz)), 124.4 (s, CArH), 124.5 (s, CArH), 131.0 (s, CArH), 134.2 (s, CArH), 140.8 (s, CIV), 145.8 (s, CH (IPr)), 148.9 (s, CIV), 177.5 (s, Ccarbene); 19F{1H} NMR (282 MHz, CDCl3, 298 K) δ (ppm) −78.6 (s); anal. calcd for C33H41CuF3N3O3S: C, 58.26; H, 6.07; N, 6.18; found: C

• (IPr)), 31.3 (s, CCH3), 35.0 (s, CIV), 37.6 (s, CH3), 123.4 (s, CIV), 123.9 (s, CArH), 124.2 (s, C4 and C5), 124.4 (s, CArH), 126.6 (s, CArH), 129.4 (s, CArH), 130.5 (s, CArH), 130.9 (s, CArH), 134.3 (s, CIV), 144.8 (s, CIV), 145.2 (s, CIV), 152.0 (s, CIV), 152.8 (s, CIV), 179.4 (s, Ccarbene); 19F{1H

• (s, CHCH3 (Triaz)), 31.3 (s, CCH3), 35.0 (s, CIV), 37.8 (s, CH3), 123.6 (s, CIV), 124 (s, CArH), 126.2 (s, CArH), 129.0 (s, CArH), 131.1 (s, CArH), 134.3 (s, CIV), 145.0 (s, CIV), 149.2 (s, CIV), 153.4 (s, CIV); 19F{1H} NMR (282 MHz, CDCl3, 298 K) δ (ppm) −154.9 (s, BF4), −155.0 (s, BF4); anal. calcd

Synthesis and circularly polarized luminescence properties of BINOL-derived bisbenzofuro[2,3-b:3’,2’-e]pyridines (BBZFPys)

• Ryo Takishima,
• Yuji Nishii,
• Tomoaki Hinoue,
• Yoshitane Imai and
• Masahiro Miura

Beilstein J. Org. Chem. 2020, 16, 325–336, doi:10.3762/bjoc.16.32

• ), 19F NMR (376 MHz, CDCl3) δ 69.06; HRMS–APCI (m/z): [M + H]+ calcd for C38H35F2N2O2, 589.2644; found, 589.2661. The enantiomeric purity was confirmed by HPLC analysis: CHIRAL ART Cellulose-SB column, n-hexane/chloroform 95:5, 1.0 mL/min, 40 °C; (S)-2: tR = 9.86 min, (R)-2: tR = 21.29 min, UV detection

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

• Atsunori Mori,
• Keisuke Fujita,
• Chihiro Kubota,
• Toyoko Suzuki,
• Kentaro Okano,
• Takuya Matsumoto,
• Takashi Nishino and
• Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

• MHz), 19F NMR (376 MHz), and 13C{1H} NMR (100 MHz) spectra were measured on a JEOL ECZ400 spectrometer as a CDCl3 solution, unless otherwise noted. The chemical shifts were expressed in ppm with CHCl3 (7.26 ppm for 1H), C6F6 (−164.9 ppm for 19F), or CDCl3 (77.16 ppm for 13C) as internal standards. IR

• Hz, 2H), 6.79 (s, 1H), 6.91 (d, J = 5.0 Hz, 1H), 7.17 (d, J = 5.0 Hz, 1H); 13C{1H} NMR (100 MHz, CDCl3) δ 0.4, 2.1, 18.3, 20.5 (br), 23.4, 27.4, 29.0, 30.4 (t, J = 22 Hz), 34.5, 124.3, 125.1, 126.0, 129.7, 130.2, 133.6, 137.6, 140.3; 19F NMR (376 MHz, C6F6) δ −129.2, −127.6, −117.6, −84.2; IR (ATR

• , 1H); 13C{1H} NMR (100 MHz, CDCl3) δ −0.2, 2.0, 17.6, 20.5 (br), 23.1, 27.4, 29.0, 30.4 (t, J = 22 Hz), 34.3, 124.3, 125.1, 126.0, 129.7, 130.2, 133.6, 137.6, 140.2; 19F NMR (376 MHz, C6F6) δ −129.2, −127.6, −117.6, −84.2; IR (ATR): 2958, 1252, 1233, 1167, 1134, 1046, 870, 841, 800, 783, 754, 719, 689

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

• Vuyisa Mzozoyana,
• Fanie R. van Heerden and
• Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

• conditions via a three-step reaction. The solution-state 1H NMR spectra of 6 showed a strong intramolecular interaction between F and H5 (JFH = 2.6 Hz) and 13C NMR suggested that this C–F···H–C coupling is a through-space interaction. The 2D 19F-{1H} HOESY and 1H-{19F} 1D experiments were done to confirm

• ). The H5 signal was expected to be a doublet (not a dd) due to 3J coupling to H6, since an H,H-COSY experiment does not show coupling between H5 and H8 (Figure S9, Supporting Information File 1). It became clear that the splitting of the signal from H5 was due to coupling with the 19F atom by comparing

• the spectra from the 1H and 1H-{19F} experiments (Figure 1) which showed the H5 peak as a doublet with 19F decoupling. While the doublet-of-doublets signal for H5 collapses into a doublet with 19F decoupling, there are no significant changes in the line-shape for the signal of H3 with 19F decoupling

Efficient method for propargylation of aldehydes promoted by allenylboron compounds under microwave irradiation

• Jucleiton J. R. Freitas,
• Queila P. S. B. Freitas,
• Silvia R. C. P. Andrade,
• Juliano C. R. Freitas,
• Roberta A. Oliveira and
• Paulo H. Menezes

Beilstein J. Org. Chem. 2020, 16, 168–174, doi:10.3762/bjoc.16.19

• propargylating agent in a very regioselective way [36][37]. Thus, allenylboronic acid pinacol ester (1) was converted into the corresponding trifluoroborate using the procedure described by Lloyd-Jones and co-worker [38]. The desired product 4 was obtained in good yield and characterized by 1H, 13C, 11B and 19F

• solvents.a Supporting Information Supporting Information File 252: Experimental procedures and 1H, 13C, 11B and 19F NMR spectra for all synthesized compounds. Funding This work was jointly supported by grants from CNPq and FACEPE.

Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization

• Valentina A. Ol’shevskaya,
• Elena G. Kononova and
• Andrei V. Zaitsev

Beilstein J. Org. Chem. 2019, 15, 2704–2709, doi:10.3762/bjoc.15.263

• ) or Ni(II) with N-propargylmaleimide via the CuAAC click reaction to afford fluorinated porphyrin–triazole–maleimide conjugates. New maleimide derivatives were isolated in reasonable yields and identified by UV–vis, 1H NMR, 19F NMR spectroscopy and mass-spectrometry. Keywords: chlorin; maleimide

• was transformed into the corresponding maleimide 12 in 25% yield on the reaction with maleic anhydride according to the standard procedure. Chlorin 12 was metalated with Zn(OAc)2/CHCl3/MeOH giving chlorin 13 in 92% yield. (Scheme 2). All prepared compounds have been structurally identified by 1H, 19F

Synthesis of aryl-substituted thieno[3,2-b]thiophene derivatives and their use for N,S-heterotetracene construction

• Nadezhda S. Demina,
• Nikita A. Kazin,
• Nikolay A. Rasputin,
• Roman A. Irgashev and
• Gennady L. Rusinov

Beilstein J. Org. Chem. 2019, 15, 2678–2683, doi:10.3762/bjoc.15.261

• Crystallographic Data Centre via https://www.ccdc.cam.ac.uk/data_request/cif. Supporting Information File 569: Experimental section and copies of 1H, 13C and 19F NMR spectra of new compounds. Supporting Information File 570: Crystal data of 7d. Acknowledgements This study was supported by the Russian Foundation

1,5-Phosphonium betaines from N-triflylpropiolamides, triphenylphosphane, and active methylene compounds

• Vito A. Fiore,
• Chiara Freisler and
• Gerhard Maas

Beilstein J. Org. Chem. 2019, 15, 2603–2611, doi:10.3762/bjoc.15.253

• triphenylphosphane and N-triflyl-propiolanilide 1a in dichloromethane yielded a product mixture, from which only N-phenyltriflylamide (HN(Ph)Tf; 19F NMR: δ −76.5 ppm rel. to C6F6) could be extracted, the remainder being undefined oligomeric/polymeric material. However, when an N-triflylpropiolamide 1a–e (1.03 molar

• Information Supporting Information File 640: Experimental procedures, characterization data, NMR spectra (1H, 13C, 31P, 19F) and IR spectra for the synthesized compounds, and data for the X-ray crystal structure determinations.

Mono- and bithiophene-substituted diarylethene photoswitches with emissive open or closed forms

• A. Lennart Schleper,
• Mariano L. Bossi,
• Vladimir N. Belov and
• Stefan W. Hell

Beilstein J. Org. Chem. 2019, 15, 2344–2354, doi:10.3762/bjoc.15.227

• DAE 4 could not be isolated by column chromatography on regular silica gel. Instead, monoiodide 4 was obtained in 14% yield as colorless solid after preparative HPLC on a reversed phase (C18) column and lyophilization. The constitution and structure of 4 was confirmed by HRMS, 1H and 19F NMR

• closed form (formed by handling in the lab not fully protected from light) were detected by HPLC (Figure S33 in Supporting Information File 1). The constitution, structures, and purities of the final products were confirmed by HRMS, 1H and 19F NMR spectroscopy, as well as analytical HPLC. Saponification

Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene

• Luna Kono,
• Yuma Nakagawa,
• Ayako Fujimoto,
• Ryo Nishimura,
• Yohei Hattori,
• Toshiki Mutai,
• Nobuhiro Yasuda,
• Kenichi Koizumi,
• Satoshi Yokojima,
• Shinichiro Nakamura and
• Kingo Uchida

Beilstein J. Org. Chem. 2019, 15, 2204–2212, doi:10.3762/bjoc.15.217

• were used without further purification. Melting points were determined on a Yanaco MP-500D melting point apparatus and are uncorrected. 1H (400 MHz), 13C (100 MHz) and 19F NMR (376 MHz) spectra were recorded on a JEOL JNM-400 spectrometer at ambient temperature. The splitting patterns are designated as

• , 123.9, 123.0, 122.5, 122.2, 121.7, 121.2, 119.4, 117.5, 113.2, 111.0, 55.5, 14.7, 14.77; 19F NMR (376 MHz, CDCl3, ppm) δ −113.1 (s, 2F), −113.3 (s, 2F), −135.0 (s, 2F); HRMS (MALDI–TOF) m/z: calcd for C35H24F6N2OS2, 666.1234; found, 666.1229. Diarylethene (1o) To 5 mL of dichloromethane anhydrous

• , 142.8, 142.6, 142.1, 141.4, 137.7, 133.4, 130.1, 129.2, 129.2, 128.2, 126.3, 125.9, 125.9, 125.8, 125.8, 124.6, 123.7, 122.5, 121.5, 120.7, 119.2, 117.9, 117.0, 116.1, 107.3, 14.7, 14.7; 19F NMR (376 MHz, CDCl3, ppm) δ −113.1 (s, 2F), −113.3 (s, 2F), −135.0 (s, 2F); HRMS (MALDI–TOF) m/z: calcd for

Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts

• Kenta Tanaka,
• Yuta Tanaka,
• Mami Kishimoto,
• Yujiro Hoshino and
• Kiyoshi Honda

Beilstein J. Org. Chem. 2019, 15, 2105–2112, doi:10.3762/bjoc.15.208

• ), coupling constants, integration. 13C NMR spectra were recorded on a Bruker DRX-500 (126 MHz) or a JEOL JNM ECA-500 (126 MHz) spectrometer with complete proton decoupling. Chemical shifts are reported in ppm with the solvent resonance as the internal standard (CDCl3: δ 77.0). 19F NMR spectra were recorded

• , 6H); 13C NMR (126 MHz, CDCl3) δ 168.3. 165.5. 165.2. 147.8. 142.2. 127.2. 127.0. 125.6. 116.9. 101.8. 101.4. 57.7. 56.7; 19F NMR (376 MHz, CDCl3) δ −81.3; IR (ATR): 1585, 1219, 1143, 1026, 634 cm−1; HRMS (ESI+) m/z: [M]+ calcd for C23H21O4S, 393.1155; found, 393.1171; anal. calcd for C24H21F3O7S2: C

• Hz, 1H), 6.93 (dd, J = 7.1, 1.1 Hz, 1H), 6.43 (d, J = 2.2 Hz, 2H), 4.15 (s, 6H), 2.96 (s, 6H); 13C NMR (126 MHz, CDCl3) δ 168.4, 165.2, 164.7, 147.6, 140.7, 132.1, 132.0, 128.2, 127.5, 126.4, 125.9, 125.0, 124.4, 121.3, 117.6, 102.0, 101.5, 57.7, 56.6; 19F NMR (376 MHz, CDCl3) δ −81.3; IR (ATR): 1593

1,2,3,4-Tetrahydro-1,4,5,8-tetraazaanthracene revisited: properties and structural evidence of aromaticity loss

• Arnault Heynderickx,
• Sébastien Nénon,
• Olivier Siri,
• Vladimir Lokshin and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2019, 15, 2059–2068, doi:10.3762/bjoc.15.203

• , 146.58; 19F NMR (DMSO-d6) δ 148; HRMS (ESIMS) m/z: [M2+]; calcd. for C12H16N42+ 216.1364 108.0682; found, 108.0683. 1,4-Diacetyl)-1,2,3,4-tetrahydropyrazino[2,3-g]quinoxaline (9): 1,2,3,4-Tetrahydropyrazino[2,3-g]quinoxaline (3, 500 mg, 2.68 mmol) was added to 20 mL of acetic anhydride and the mixture

Synthesis and anion binding properties of phthalimide-containing corona[6]arenes

• Meng-Di Gu,
• Yao Lu and
• Mei-Xiang Wang

Beilstein J. Org. Chem. 2019, 15, 1976–1983, doi:10.3762/bjoc.15.193

• = 6.4 Hz, 6H); 19F NMR (376 MHz, DMSO-d6, 25 °C) δ 59.8; 13C NMR (101 MHz, MeCN-d3, 25 °C) δ 167.1, 164.5, 154.8, 145.0, 144.2, 131.2, 125.9, 124.7 (q,1J(C, F) = 271.6 Hz), 124.5, 120.9 (q, 2J(C, F) = 31.8 Hz), 117.1, 36.5, 35.5, 28.2; IR (KBr, cm−1) ν: 3372, 3080, 2937, 1775, 1717, 1603, 1545, 1382

The cyclopropylcarbinyl route to γ-silyl carbocations

• Xavier Creary

Beilstein J. Org. Chem. 2019, 15, 1769–1780, doi:10.3762/bjoc.15.170

• . Stereochemistry of the alcohol 58 was established by long-range 19F coupling to the cis-trimethylsilyl group hydrogens (JH-F = 0.9 Hz). Long-range 19F coupling to the TMS methyl groups of 58 was also observed in the 13C NMR spectrum (JC-F = 2.1 Hz) [64][65]. This long-range 19F coupling is not observed when the