Self and directed assembly: people and molecules

• Tony D. James

Beilstein J. Org. Chem. 2016, 12, 391–405, doi:10.3762/bjoc.12.42

• [74][75] using predominantly 1H NMR but we also demonstrated that by using 4-fluoro-2-formylbenzeneboronic acids then 19F NMR could also be used [76]. We have also used the three component systems in collaboration with Jim Tucker (University of Birmingham) to measure the ee of binol via

Diastereoselective synthesis of new O-alkylated and C-branched inositols and their corresponding fluoro analogues

• Charlotte Collet,
• Françoise Chrétien,
• Yves Chapleur and
• Sandrine Lamandé-Langle

Beilstein J. Org. Chem. 2016, 12, 353–361, doi:10.3762/bjoc.12.39

• fully acetylated inositols. The fluorination reactions using potassium fluoride, 18-crown-6 in acetonitrile at 70 °C [53], TBAF in acetonitrile at 60 °C for 2 h [54] or KHF2 and 18-crown-6 in acetonitrile for 2 h at 60 °C [55] were performed. However, 19F NMR analyses of the reaction mixtures did not

• and scyllo-22 derivatives, which were not acetylated on the tertiary position; in order to avoid the acyl migration. The treatment of myo-22 with KF, 18-crown-6 in acetonitrile [53] at room temperature (optimal conditions) furnished the fluorinated compound myo-25 in 70% yield. The 19F NMR spectrum

• Information Supporting Information File 154: Experimental procedures, characterization data and copies of 1H, 13C, and 19F NMR spectra of all new compounds. Acknowledgements We thank the Ministère de l’enseignement supérieur for a doctoral fellowship to CC. This work was partially supported by funding from

Study on the synthesis of the cyclopenta[f]indole core of raputindole A

• Nils Marsch,
• Mario Kock and
• Thomas Lindel

Beilstein J. Org. Chem. 2016, 12, 334–342, doi:10.3762/bjoc.12.36

• 100 °C. Unfortunately, all reactions gave intractably complex mixtures. 1H and 19F NMR analysis suggested that cleavage of at least one Boc-protecting group had occurred. Additionally, the triflate was still visible in the 19F NMR spectrum, thus indicating that oxidative addition to the Pd catalyst

Synthesis and nucleophilic aromatic substitution of 3-fluoro-5-nitro-1-(pentafluorosulfanyl)benzene

• Javier Ajenjo,
• Martin Greenhall,
• Camillo Zarantonello and
• Petr Beier

Beilstein J. Org. Chem. 2016, 12, 192–197, doi:10.3762/bjoc.12.21

• -(pentafluorosulfanyl)benzene (1). Synthesis of 2 by fluorodenitration of 5. SNAr reactions of 2. VNS reactions of 2. Supporting Information Synthesis and characterization of all products, copies of 1H, 13C, and 19F NMR spectra of newly synthesized products. Supporting Information File 124: Experimental part and

Synthesis and reactivity of aliphatic sulfur pentafluorides from substituted (pentafluorosulfanyl)benzenes

• Norbert Vida,
• Jiří Václavík and
• Petr Beier

Beilstein J. Org. Chem. 2016, 12, 110–116, doi:10.3762/bjoc.12.12

• . Maleic acid 4 was identified in the mixture (25% 19F NMR yield, Scheme 4) but chromatographic separation, crystallization or derivatization (CH2N2) attempts were not successful. Nevertheless, these results show that SF5-substituted para-benzoquinones are most likely intermediates in the formation of 4 by

• good stability at ambient temperature in a strongly acidic and oxidizing environment. However, lactone 3 was found to be unstable in water or in aqueous base. Monitoring a solution of 3 in D2O by 1H and 19F NMR spectroscopy showed a gradual disappearance of the SF5 signal. After 55 h at ambient

• Diels–Alder reaction of cyclopentadiene with 12. Selected bond lengths are given in Ångström. Oxidation of SF5-anisole and phenol. 19F NMR yields are shown (isolated yields in parentheses). Proposed mechanism for the formation of 3 and 4 from SF5 aromatics 1 and 2. Oxidation of anisole 10 and phenol 11

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• due to host–guest complexation as observed by 19F NMR spectroscopy [47]. Subsequently, Islam et al. observed the host–guest complexation of the linear alkyl substituents n-C8H17, n-C16H33 and n-C20H41 of hydrophobically substituted alkali-soluble emulsion (HASE) polymers by methylated β-CD using gel

Pyridylidene ligand facilitates gold-catalyzed oxidative C–H arylation of heterocycles

• Kazuhiro Hata,
• Hideto Ito,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2015, 11, 2737–2746, doi:10.3762/bjoc.11.295

• observation of PyC-gold(III) species under the catalytic conditions. The treatment of AuCl(PyC) with 5-fluoroiodosobenzoic acid (5F-IBA) and CSA in CDCl3/CD3OD at 65 °C resulted in the full consumption of 5F-IBA within 30 min (monitored by 19F NMR). While the resulting mixture seemed to contain several PyC

• analysis revealed that about 90% of AuCl(PyC) was consumed and AuCl3(PyC) was produced in 50% NMR yield. Fortunately, the isolation from the messy crude mixtures was accomplished to give AuCl3(PyC) in 24% isolated yield. We also conducted the same experiment with the AuCl(IPr) complex. From the 19F and 1H

Carbon–carbon bond cleavage for Cu-mediated aromatic trifluoromethylations and pentafluoroethylations

• Tsuyuka Sugiishi,
• Hideki Amii,
• Kohsuke Aikawa and
• Koichi Mikami

Beilstein J. Org. Chem. 2015, 11, 2661–2670, doi:10.3762/bjoc.11.286

• determined by 19F NMR analysis using CF3CH2OH as an internal standard. C–H trifluoromethylation of arenes using trifluoroacetic acid. CF3Cu generated from chlorofluoroacetate and CuI. [18F]Trifluoromethyation with difluorocarbenes for PET. aRadiochemical yield determined by HPLC. Trifluoromethylation with

• determined by 19F NMR analysis using benzotrifluoride (BTF) or (trifluoromethoxy)benzene as an internal standard. bIsolated yield. c4 equivalents of CF3CF2Cu reagent were used. Perfluoroalkylation reactions of arylboronic acids. aIsolated yield. bDMF was used instead of toluene as a solvent. c4 equivalents

• of CnFn+1Cu reagent were used. dPinacolboronate ester (Bpin) was used instead of boronic acid. eYield was determined by 19F NMR analysis using BTF as an internal standard. Trifluoromethylation with silylated hemiaminal of fluoral. Catalytic trifluoromethylation with a fluoral derivative. The scope of

A new approach to ferrocene derived alkenes via copper-catalyzed olefination

• Vasily M. Muzalevskiy,
• Aleksei V. Shastin,
• Alexandra D. Demidovich,
• Namiq G. Shikhaliev,
• Abel M. Magerramov,
• Victor N. Khrustalev,
• Rustem D. Rakhimov,
• Sergey Z. Vatsadze and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2015, 11, 2072–2078, doi:10.3762/bjoc.11.223

• similar alkenes [38][39][40]. The trifluoromethyl group of the Z-isomers of compounds 3–5 resonates in higher field in 19F NMR (3: −72.8 ppm, 4: −67.1 ppm, 5: −69.0 ppm) than that of the E-isomers (3: −67.9 ppm, 4: −60.2 ppm, 5: −62.4 ppm). In the case of compound 3 an additional conformation can be seen

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• :1 stoichiometry for the solid adducts, and 19F NMR spectra showed downfield chemical shifting of the ICF2 signal of 1a and 1b [4]. Clearly, an important intermolecular interaction occurred which led to the solidification of the mixtures [5]. However, we did not obtain the crystal structure of the

Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers

• Davide Bello and
• David O'Hagan

Beilstein J. Org. Chem. 2015, 11, 1902–1909, doi:10.3762/bjoc.11.205

• improved outcome (Table 2, entry 1). The high conversion of 1a but low product (2a and 3a) isolation is attributed to substrate decomposition. When the reaction is followed by 19F NMR (vide infra), the presence of the hydrofluorinated products 2a and 3a is obvious and the anion BF4−, when using BF3·Et2O

• group, possibly with its participation in the reaction process. 19F NMR was used to probe changes in the Lewis acids in the reaction. Ratios of 1:2 Lewis acid:3HF·Et3N mixtures in CD2Cl2 were stirred at room temperature for 2 hours, and the aliquots (0.7 mL) were assayed in Teflon NMR tubes. 19F NMR

• ]2− is rather unreactive [18], similar to the BF4− anion. We then analysed both reaction mixtures by 19F NMR, separately in CD2Cl2, in the presence of sulfide 1a, after stirring at room temperature for 2 hours. This showed the presence of 2a and 3a, as well anions BF4− or [TiF6]2− and also an excess

Influence of bulky yet flexible N-heterocyclic carbene ligands in gold catalysis

• Alba Collado,
• Scott R. Patrick,
• Danila Gasperini,
• Sebastien Meiries and
• Steven P. Nolan

Beilstein J. Org. Chem. 2015, 11, 1809–1814, doi:10.3762/bjoc.11.196

• trifluoromethanesulfonimide. Following this silver-free procedure, [Au(ITent)(OH)] complexes 4–6 were reacted with HNTf2 to obtain the corresponding [Au(ITent)(NTf2)] species 7–9 which were isolated as white solids in good to excellent yields (Scheme 2). Complexes 7–9 were characterised by 1H, 13C{1H}, and 19F{1H} NMR

• ligands [46][50]. Each 19F{1H} NMR spectrum contains a singlet at ca. −76 ppm, in agreement with the presence of an inner-sphere NTf2 ligand [50]. Catalytic transformations Once fully characterised, the catalytic activity of the new complexes was investigated. To this end, three model reactions were

Grubbs–Hoveyda type catalysts bearing a dicationic N-heterocyclic carbene for biphasic olefin metathesis reactions in ionic liquids

• Maximilian Koy,
• Hagen J. Altmann,
• Benjamin Autenrieth,
• Wolfgang Frey and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2015, 11, 1632–1638, doi:10.3762/bjoc.11.178

• ) δ 292.9 (Ru=CH), 211.6 (N-C=N), 153.5, 148.7, 145.9, 143.1, 141.2, 131.3, 123.6, 123.5, 121.8, 114.5 (C6H2, C6H4), 127.3, 124.1, 120.9, 117.7 (CF3-SO3−, q, JC-F = 322.5 Hz), 76.4 (CH(CH3)2), 57.9 (N(CH3)3), 52.6, 21.9, 20.3 (CH(CH3)2, Ar-CH3); 19F NMR (DMF-d7) δ −78.5; FTIR (ATR, cm−1) : 1589 (s

Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF₅-substituted phenylboronic esters and iodobenzenes

• George Iakobson,
• Junyi Du,
• Alexandra M. Z. Slawin and
• Petr Beier

Beilstein J. Org. Chem. 2015, 11, 1494–1502, doi:10.3762/bjoc.11.162

• [68] applied to 3b provided 8b in only 25% 19F NMR yield. To extend the synthetic utility of the pyridine-mediated derivatization of aryldiazonium tetrafluoroborates we investigated the reaction with iodobenzene and iodine as efficient scavengers of aryl radicals [83][84]. A competitive experiment

• tetrafluoroborates 3a and boronates 2b. One pot diazotization-borylation of 1ba. Hydrodediazoniation of 3a and 3b with THFa. Supporting Information Synthesis and characterization of all products, copies of 1H, 13C, and 19F NMR spectra of newly synthesized products, and X-ray crystallographic files of the compounds

Intermolecular addition reactions of N-alkyl-N-chlorosulfonamides to unsaturated compounds

• Gerold Heuger and
• Richard Göttlich

Beilstein J. Org. Chem. 2015, 11, 1226–1234, doi:10.3762/bjoc.11.136

• , 1H), 7.05 (t, J = 8.5 Hz, 2H), 7.30 (d, J = 8.4 Hz, 2H), 7.39 (dd, J = 8.7, 5.1 Hz, 2H), 7.64 (d, J = 8.4 Hz, 2H); 13C NMR (75 MHz, CDCl3) δ 21.4, 37.0, 58.0, 60.4, 115.8 (d, J = 26.8 Hz), 127.3, 129.3 (d, J = 8.3 Hz), 129.8, 134.5, 134.7, 143.6, 162.8 (d, J = 246.8 Hz); 19F NMR (282 MHz, CDCl3) δ

Orthogonal dual-modification of proteins for the engineering of multivalent protein scaffolds

• Michaela Mühlberg,
• Michael G. Hoesl,
• Christian Kuehne,
• Jens Dernedde,
• Nediljko Budisa and
• Christian P. R. Hackenberger

Beilstein J. Org. Chem. 2015, 11, 784–791, doi:10.3762/bjoc.11.88

• ligation and CuAAC. Supporting Information Details on materials, protein design, construction of the expression plasmids, protein expression and purification, mass spectrometry data for the expressed proteins, general methods, synthetic protocols and analytical data (including 1H, 13C and 19F NMR spectra

Trifluoromethyl-substituted tetrathiafulvalenes

• Olivier Jeannin,
• Frédéric Barrière and
• Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

• from Na/benzophenone. CH3CN and CH2Cl2 were distilled over P2O5 and MeOH over Mg/I2. Column chromatography was performed on silica gel. 1H, 13C and 19F NMR spectra were obtained on a Bruker Avance DRX500 spectrometer at 500.04 MHz for 1H, 470.28 MHz for 19F and 125.75 MHz for 13C. Chemical shifts were

• gaseous NH3. The resulting suspension was stirred for 90 min and filtered. The solid was recrystallized from CH3CN to afford 7 as red–burgundy needles (120 mg, 0.3 mmol). Yield: 63%; mp dec. 150–160 °C; 1H NMR (d6-acetone) δ 3.44 (s, 4H), 7.48 ppm (d, 2H); 19F NMR (CDCl3) δ −58.53 (s) ppm. Anal. calcd for

• %; mp 176 °C (CH2Cl2/hexane); 1H NMR (CDCl3) δ 3.32 (s, 4H) ppm; 13C NMR (CDCl3) δ 30.10 (s), 104.58 (s), 107.86 (q, J3CF = 3.84 Hz), 108.47 (s), 113.97 (s), 114.20 (s), 118.81 (q, J1CF = 274.47 Hz), 118.30 (s), 138.43 (q, J2CF = 36.47 Hz) ppm; 19F NMR (CDCl3) δ −59.20 (s) ppm; Anal. calcd for

Weakly nucleophilic potassium aryltrifluoroborates in palladium-catalyzed Suzuki–Miyaura reactions: relative reactivity of K[4-RC₆F₄BF₃] and the role of silver-assistance in acceleration of transmetallation

• Vadim V. Bardin,
• Anton Yu. Shabalin and
• Nicolay Yu. Adonin

Beilstein J. Org. Chem. 2015, 11, 608–616, doi:10.3762/bjoc.11.68

• 5% (19F NMR) (Scheme 3). It should be noted that 2,3,5,6-tetrafluoropyridine was not observed in the reaction mixtures in both cases. The use of the electron-rich C-electrophile, 4-IC6H4CH3 (9), instead of 3 leads to biphenyls 4-(4'-CH3C6H4)C6F4R (10c–f,h–p) in 60–80% preparative yields (see Table 2

• of equimolar mixtures of K[C6F5BF3] (1a) and K[4-RC6F4BF3] (1b–p) with 11. The reactions were carried out over a short period (5–15 min) and the product ratios were determined by analyzing the crude reaction mixtures with 19F NMR spectroscopy. The relative reactivity was determined as Crel = CR / CF

• groups are not reported as yet except inductive constants σI (C6F5) [43][45][46] and σI (2,3,5,6-C6F4H) [43], and resonance constants σR° (C6F5) [45]. We bridge this gap using a series of biphenyls 4a–r and 5a–r and determine SEP of 4-RC6F4 groups using the Taft's method [42]. The 19F NMR spectra were

The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess and
• Viktor I. Saloutin

Beilstein J. Org. Chem. 2015, 11, 385–391, doi:10.3762/bjoc.11.44

• 19F NMR spectra of all new compounds. Acknowledgements This research was financially supported by the Russian Foundation for Basic Research (Grant 13-03-00617), the Ural Branch of Russian Academy of Sciences (Project 15-21-3-9) and the State Program for Supporting of Leading Scientific School of the

Highly selective electrochemical fluorination of dithioacetal derivatives bearing electron-withdrawing substituents at the position α to the sulfur atom using poly(HF) salts

• Bin Yin,
• Shinsuke Inagi and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2015, 11, 85–91, doi:10.3762/bjoc.11.12

• of all new compounds including copies of 1H NMR, 13C NMR and 19F NMR spectra. Acknowledgements We gratefully acknowledge Morita Chemical Industries Co., Ltd for supplying triethylamine poly(hydrogen fluoride) [Et3N·nHF (n = 3–5)] and tetraethylammonium fluoride poly(hydrogen fluoride) [Et4NF·nHF (n

Efficient deprotection of F-BODIPY derivatives: removal of BF₂ using Brønsted acids

• Mingfeng Yu,
• Joseph K.-H. Wong,
• Cyril Tang,
• Peter Turner,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 37–41, doi:10.3762/bjoc.11.6

• ), CH3OH, rt, 15 min (see Table 1 for yields). Removal of BF2 from F-BODIPYs using Brønsted acids. Supporting Information Supporting Information File 7: Experimental procedures and characterization data; crystallographic information for 8; 1H, 13C, 11B & 19F NMR spectra of novel compounds 3, 4, 14, 15, 16

An integrated photocatalytic/enzymatic system for the reduction of CO₂ to methanol in bioglycerol–water

• Michele Aresta,
• Angela Dibenedetto,
• Tomasz Baran,
• Antonella Angelini,
• Przemysław Łabuz and
• Wojciech Macyk

Beilstein J. Org. Chem. 2014, 10, 2556–2565, doi:10.3762/bjoc.10.267

• in the literature [8] to be active in oxidation processes of waste organics, neither TiO2 loaded with anionic [CrF5(H2O)]2− nor CrF3 on TiO2 (used for reduction purposes) has been described so far. The 19F NMR spectrum confirms the presence of the anionic form on the TiO2 surface with a signal at 121

Synthesis of trifluoromethyl-substituted pyrazolo[4,3-c]pyridines – sequential versus multicomponent reaction approach

• Barbara Palka,
• Angela Di Capua,
• Maurizio Anzini,
• Gyté Vilkauskaité,
• Algirdas Šačkus and
• Wolfgang Holzer

Beilstein J. Org. Chem. 2014, 10, 1759–1764, doi:10.3762/bjoc.10.183

• . Oximes derived from (intermediate) 5-alkynyl-1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carbaldehydes were transformed into the corresponding 1H-pyrazolo[4,3-c]pyridine 5-oxides by silver triflate-catalyzed cyclization. Detailed NMR spectroscopic investigations (1H, 13C, 15N and 19F) were undertaken with

• all obtained products. Keywords: microwave-assisted reactions; multicomponent reactions; NMR (1H; 13C; 15N; 19F); Sonogashira coupling; trifluoromethylpyrazoles; Introduction Fluorine-containing compounds play an important role in medicinal and pharmaceutical chemistry as well as in agrochemistry [1

• investigations In Supporting Information File 1 the NMR spectroscopic data of all compounds treated within this study are indicated. Full and unambiguous assignment of all 1H, 13C, 15N and 19F NMR resonances was achieved by combining standard NMR techniques [32], such as fully 1H-coupled 13C NMR spectra, APT

The chemoenzymatic synthesis of clofarabine and related 2′-deoxyfluoroarabinosyl nucleosides: the electronic and stereochemical factors determining substrate recognition by E. coli nucleoside phosphorylases

• Ilja V. Fateev,
• Konstantin V. Antonov,
• Irina D. Konstantinova,
• Tatyana I. Muravyova,
• Frank Seela,
• Roman S. Esipov,
• Anatoly I. Miroshnikov and
• Igor A. Mikhailopulo

Beilstein J. Org. Chem. 2014, 10, 1657–1669, doi:10.3762/bjoc.10.173

• white powder in 42–50 % yield. The structures of the α- and β-anomers 12a and 12b were verified by a careful analysis of the 1H and 13C NMR spectra {[1H,1H] and [1H,13C] 2D COSY and NOESY spectra} as well as by the 19F and 31P NMR and by comparison with published 1H and 13C NMR data for the α-anomer 12a

• (6.5 Hz) taken from the 19F and 31P NMR spectra, respectively, are in fair agreement with the calculated structures and the analogous couplings obtained from the 1H NMR spectrum. A similar analysis of the stereochemistry of the α-D-arabinofuranose-1-phosphate (Ara-1P) revealed a very close resemblance

• 4JH2,P of 1.28 Hz observed in the 1H NMR spectrum results from the W-like arrangement of the interacting nuclei and is present in the calculated stereochemistry of the β-anomer 12b (Figure S1 in Supporting Information File 1). It should be stressed that the 19F and 31P NMR data also give strong support

An experimental and theoretical NMR study of NH-benzimidazoles in solution and in the solid state: proton transfer and tautomerism

• Carla I. Nieto,
• Pilar Cabildo,
• M. Ángeles García,
• Rosa M. Claramunt,
• Ibon Alkorta and
• José Elguero

Beilstein J. Org. Chem. 2014, 10, 1620–1629, doi:10.3762/bjoc.10.168

• the F1 domain and a sine-bell window function in both dimensions was applied prior to Fourier transformation. For 19F NMR (379.50 MHz) a 5 mm QNP direct-detection probehead equipped with a z-gradient coil, at 300 K was required. Chemical shifts (δ) are given from internal solvent, DMSO-d6 2.49 and

• HMPA-d18 2.57 for 1H; 39.5 and 35.8 for 13C, and for 15N and 19F NMR, nitromethane (0.00) and one drop of CFCl3 in CDCl3 (0.00) were used as external references Typical parameters for 1H NMR were: spectral width 4800 Hz and pulse width 10.25 μs at an attenuation level of −3.0 dB. For 13C NMR: spectral

• width 21 kHz, pulse width 8.75 μs at an attenuation level of −3 dB and relaxation delay 2 s, WALTZ-16 was used for broadband proton decoupling; the FIDS were multiplied by an exponential weighting (lb = 1Hz) before Fourier transformation. For 19F NMR: spectral width 55 kHz, pulse width 13.57 μs at an