Synthesis of fluoro-functionalized diaryl-λ³-iodonium salts and their cytotoxicity against human lymphoma U937 cells

• Prajwalita Das,
• Etsuko Tokunaga,
• Hidehiko Akiyama,
• Hiroki Doi,
• Norimichi Saito and
• Norio Shibata

Beilstein J. Org. Chem. 2018, 14, 364–372, doi:10.3762/bjoc.14.24

• neutral size 63–210 μm). The 1H NMR (300 MHz), 19F NMR (282 MHz), and 13C NMR (125 MHz) spectra for solution in CDCl3 or (CD3)2CO were recorded on Varian Mercury 300 and Bruker Avance 500 spectrometers. Chemical shifts (δ) are expressed in ppm downfield from TMS (δ = 0.00) or C6F6 [δ = −162.2 (CDCl3) or

• . HRMS (EI–TOF) m/z [M]+: calcd for C6H4F5SI, 329.8999; found, 329.9010; 1H NMR (CDCl3, 300 MHz) δ 7.11 (t, J = 9 Hz, 1H), 7.41–7.47 (m, 1H), 7.80 (dd, J = 9 Hz, 3 Hz, 1H), 8.14 (d, J = 9 Hz, 1H); 19F NMR (CDCl3, 282 MHz) δ 63.55 (d, J = 155.1 Hz, 4F), 83.56 (q, J = 155.1 Hz, 1F); 13C{1H}NMR (CDCl3, 126

• Hz, 1H); 19F NMR ((CD3)2CO), 282 MHz) δ = –79.88 (s, 3F), 64.09 (d, J = 149.5 Hz, 4F), 81.34 (q, J = 149.5 Hz, 1F); 13C{1H}NMR ((CD3)2CO), 126 MHz) δ 21.2, 27.1, 106.6, 121.9 (q, J = 318.8 Hz), 123.0, 131.8, 132.5 (t, J = 5 Hz), 133.7, 135.4, 136.9, 144.5, 147.0, 154.1–154.7 (m). (2-(Pentafluoro-λ6

Diels–Alder cycloadditions of N-arylpyrroles via aryne intermediates using diaryliodonium salts

• Huangguan Chen,
• Jianwei Han and
• Limin Wang

Beilstein J. Org. Chem. 2018, 14, 354–363, doi:10.3762/bjoc.14.23

• 2.a Scope of N-substituted pyrroles 1.a Supporting Information Supporting Information File 6: Experimental procedures and characterization data of all products, copies of 1H, 13C, 19F NMR and HRMS spectra of all compounds. Acknowledgements The work was supported by the National Nature Science

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

• have been confirmed unambiguously by HMBC, HMQC and 19F NMR studies. The authors proposed that trifluoromethyl-β-diketone exists mainly in keto form 17 under solvent-free conditions whereas under solvent-mediated conditions the enolic form 21 towards the carbonyl carbon that carries the CF3 group is

Nucleophilic fluoroalkylation/cyclization route to fluorinated phthalides

• Masanori Inaba,
• Tatsuya Sakai,
• Shun Shinada,
• Tsuyuka Sugiishi,
• Yuta Nishina,
• Norio Shibata and
• Hideki Amii

Beilstein J. Org. Chem. 2018, 14, 182–186, doi:10.3762/bjoc.14.12

• methods, synthetic procedures, 1H and 19F NMR spectra for known compound 1a and full characterization of all new compounds. Acknowledgements This article is dedicated to the memory of Professor Yoshihiko Ito (1937-2006) on the occasion of the 10th anniversary of his sudden death. The financial support of

Progress in copper-catalyzed trifluoromethylation

• Guan-bao Li,
• Chao Zhang,
• Chun Song and
• Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

• employed as the substrates, Xiao and co-workers [15] firstly used S-(trifluoromethyl)diphenylsulfonium salts in the presence of copper powder to convert the substrates into the corresponding trifluoromethylated compounds in high yield. The CuCF3 intermediate was formed in this process, as confirmed by 19F

• Cu catalysis. Trifluoromethylation of arylboronic acids reported by Sanford’s group. Isolated yield. aYields determined by 19F NMR analysis. Trifluoromethylation of arylboronic acids and vinylboronic acids reported by the group of Beller. Yields determined by 19F NMR analysis. aGC yield. bIsolated

Gram-scale preparation of negative-type liquid crystals with a CF₂CF₂-carbocycle unit via an improved short-step synthetic protocol

• Tatsuya Kumon,
• Shohei Hashishita,
• Takumi Kida,
• Shigeyuki Yamada,
• Takashi Ishihara and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 148–154, doi:10.3762/bjoc.14.10

• found to be identical to the more polar adducts based on comparison of various physical data, such as the 1H, 13C, 19F nuclear magnetic resonance (NMR) signals, retardation factors (Rf values), melting points, etc. From these analyses, 3b and 3c obtained by the present protocol were eventually

• products. Yields of all reaction steps in Scheme 2. Melting points of various 1,4-disubstituted cyclohexane-1,4-diol derivatives. Supporting Information Supporting Information File 10: Experimental procedures, characterization data, and copies of 1H, 13C and 19F NMR spectra.

Stereochemical outcomes of C–F activation reactions of benzyl fluoride

• Neil S. Keddie,
• Pier Alexandre Champagne,
• Justine Desroches,
• Jean-François Paquin and
• David O'Hagan

Beilstein J. Org. Chem. 2018, 14, 106–113, doi:10.3762/bjoc.14.6

• )-benzyl fluoride ((R)-1). Supporting Information The Supporting Information features experimental protocols and 1H, 19F (where appropriate) and 2H{1H} NMR spectra of benzyl fluoride 1 and adducts 5–10. The methods for measurement of the ee by 2H{1H} NMR are also described. Supporting Information File 131

The synthesis of the 2,3-difluorobutan-1,4-diol diastereomers

• Robert Szpera,
• Nadia Kovalenko,
• Kalaiselvi Natarajan,
• Nina Paillard and
• Bruno Linclau

Beilstein J. Org. Chem. 2017, 13, 2883–2887, doi:10.3762/bjoc.13.280

• purification was required, which was convenient on scale. The reaction of (±)-trans-2 with neat Et3N·3HF at 120 °C for 16 h led, after aqueous work-up, to (±)-anti-3 in high diastereomeric purity (see Supporting Information File 1). The 19F shift of −195.3 ppm is different compared to that of (±)-syn-3 (−204.4

• resulted in 56% yield after column chromatography. 19F NMR analysis of the crude product showed a dr of 98:2 in favour of (±)-syn-4. However, given a diastereomerically pure starting material was used, this indicates that SN1 or neighbouring group participation pathways may have occurred, although only to

The use of 4,4,4-trifluorothreonine to stabilize extended peptide structures and mimic β-strands

• Yaochun Xu,
• Isabelle Correia,
• Tap Ha-Duong,
• Nadjib Kihal,
• Jean-Louis Soulier,
• Julia Kaffy,
• Benoît Crousse,
• Olivier Lequin and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2017, 13, 2842–2853, doi:10.3762/bjoc.13.276

• activity [3][4]. Fluorinated amino acids can also be used as powerful 19F NMR probes for the study of protein–ligand interactions and enzymatic activities [5][6][7][8]. However, the development of fluorinated peptides as drug candidates seems to be largely under-exploited. Investigation on the influence of

• straightforward methodology and we have adapted Zeng’s synthesis starting from the (R)-Garner’s aldehyde. (2S,3R)-Boc-CF3-Thr(Bzl) was obtained with satisfactory yields (Scheme 1). In this synthetic pathway, the key intermediate 6 was obtained, as a mixture of two diastereoisomers (9:1, evaluated by 19F NMR) via

• release of free (2S,3S)-CF3-threonine whose diastereoselectivity was determined to be about 96% by 19F NMR. Although in most of the reported cases, the free amino acid was released into the aqueous phase, and then purified by ion-exchange chromatography, we purified the free (2S,3S)-CF3-threonine by

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• allowing access to various β-trifluoromethyl ketones 24 featuring aryl, alkyl, functionalised alkyl, alkenyl, acetal, silylated alcohol, pyran, and piperidine functionalities (R group in 24). Mechanistic studies by 19F NMR allowed to identify CF3 complexes of copper(I) and copper(III) and the predominance

Development of a fluorogenic small substrate for dipeptidyl peptidase-4

• Futa Ogawa,
• Masanori Takeda,
• Kanae Miyanaga,
• Keita Tani,
• Ryuji Yamazawa,
• Kiyoshi Ito,
• Atsushi Tarui,
• Kazuyuki Sato and
• Masaaki Omote

Beilstein J. Org. Chem. 2017, 13, 2690–2697, doi:10.3762/bjoc.13.267

• (4 Å). All commercially available materials were used as received without further purification. 1H NMR, 13C NMR and 19F NMR spectra were measured on a JEOL ECZS 400S spectrometer (1H: 400MHz, 13C: 100 MHz, 19F: 376 MHz). Chemical shifts of 1H NMR and 13C NMR are reported in parts per million from

• tetramethylsilane (TMS), used as an internal standard at 0 ppm. Chemical shifts of 19F NMR are reported in parts per million from trichlorofluoromethane (CFCl3), used as an internal standard at 0 ppm. All dates are reported as follows: chemical shifts, relative integration value, multiplicity (s = singlet, d

• = 2.1, 15.8 Hz, 1H), 7.30 (dd, J = 1.8, 8.2 Hz, 1H), 7.36 (d, J = 1.8 Hz, 1H); 13C NMR (CDCl3) δ 112.9 (q, J = 33.7 Hz), 116.8, 117.9 (q, J = 33.7 Hz), 119.2, 123.3 (q, J = 269.4 Hz), 123.9 (q, J = 269.4 Hz), 124.4, 127.9, 132.7 (q, J = 6.7 Hz), 136.8 (q, J = 6.7 Hz), 146.3; 19F NMR (CDCl3) δ 89.84 (dd

Ring-size-selective construction of fluorine-containing carbocycles via intramolecular iodoarylation of 1,1-difluoro-1-alkenes

• Takeshi Fujita,
• Ryo Kinoshita,
• Tsuyoshi Takanohashi,
• Naoto Suzuki and
• Junji Ichikawa

Beilstein J. Org. Chem. 2017, 13, 2682–2689, doi:10.3762/bjoc.13.266

• . Experimental General: 1H NMR, 13C NMR, and 19F NMR spectra 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 (4-MeC6H4)2C(CF3

• )2 (for 19F NMR: δ = 97.9 ppm). IR spectra were recorded on a Horiba FT-300S spectrometer using the attenuated total reflectance (ATR) method. Mass spectra were measured on a JEOL JMS-T100GCV spectrometer. X-ray diffraction studies were performed on a Bruker APEXII ULTRA instrument equipped with a

• , 134.6, 136.8; 19F NMR (470 MHz, CDCl3) δ 124.7 (br s); IR (neat): 3068, 1489, 1454, 1126, 1147, 1097, 964, 850, 742, 696, 592 cm−1; HRMS–EI (m/z): [M]+ calcd for C21H15F2I, 432.0186; found: 432.0166. Typical procedure for the iodoarylation of 2-(3,3-difluoroallyl)biaryls 5: To a HFIP (2.5 mL) and

Electrophilic trifluoromethylselenolation of terminal alkynes with Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate

• Clément Ghiazza,
• Anis Tlili and
• Thierry Billard

Beilstein J. Org. Chem. 2017, 13, 2626–2630, doi:10.3762/bjoc.13.260

• reaction was stirred at 25 °C for 15–18 hours (conversion was checked by 19F NMR with PhOCF3 as internal standard). The crude residue was purified by chromatography to afford the desired products 3–5. Single-crystal X-ray structure of 3a. Electrophilic addition of 1a to alkynes. Yields shown are those of

• isolated products; yields determined by 19F NMR spectroscopy with PhOCF3 as an internal standard are shown in parentheses. Mechanism proposal. Perfluoroalkylselenolation of alkynes. Yields shown are those of isolated products; yields determined by 19F NMR spectroscopy with PhOCF3 as an internal standard

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

• Sergii V. Melnykov,
• Andrii S. Pataman,
• Yurii V. Dmytriv,
• Svitlana V. Shishkina,
• Mykhailo V. Vovk and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

• Organofluorine compounds now play an essential role in the development of new materials for solar cells [1][2][3], radiotracers for PET imaging [4], agrochemicals [5][6], sensitive chemical probes for 19F nuclear magnetic resonance investigation of biological experiments [7][8], and are most widely used in the

• Michael-type regioisomer 5a (Table 1, entry 1). The reaction course and the ratio of the regioisomers formed were conveniently monitored by 19F NMR spectroscopy. Acid 4a precipitated in pure form on evaporating toluene and treating the residue with diluted hydrochloric acid. Performing the reaction in a

• reaction in toluene in the presence of TEA (1 equiv) at 80 °C for 4 hours gave the best result in terms of regioselectivity and yield of 6a (Table 3, entry 1), virtually the only product formed in all the solvents used here (as evidenced by 19F NMR monitoring). The addition of malonic acid monophenyl ester

Palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides

• Tao Fan,
• Wei-Dong Meng and
• Xingang Zhang

Beilstein J. Org. Chem. 2017, 13, 2610–2616, doi:10.3762/bjoc.13.258

• Pd-catalyzed cross-coupling between 1a and 2-bromo-1,1,1-trifluorohexane (2a)a. Supporting Information Supporting Information File 400: General experimental information, experimental details on the synthesis of compounds 2–4 and 6; full characterization data as well as 1H/ 19F/ 13C NMR spectra of

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

• Marcus Baumann,
• Ian R. Baxendale and
• Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

• = triplet, q = quartet, p = pentet, m = multiplet, br. s = broad singlet, app = apparent. Data for 13C NMR are reported in terms of chemical shift (δ ppm) and multiplicity (C, CH, CH2 or CH3). Data for 19F NMR were recorded on the above instruments at a frequency of 376 MHz using CFCl3 as external standard

• 162.8 (C), 147.6 (C), 133.3 (q, J = 35 Hz, C), 132.4 (CH), 131.0 (q, J = 4 Hz, CH), 128.9 (C), 123.7 (q, J = 4 Hz, CH), 122.2 (q, J = 273 Hz, C), 113.8 (C), 64.4 (CH2), 41.2 (CH), 13.9 (CH3); 19F NMR (376 MHz, CDCl3) δ −63.2; IR (neat) ν/cm−1: 3092 (w), 2925 (w), 1732 (m), 1537 (m), 1502 (m), 1357 (m

• 164.4 (C), 135.8 (d, J = 3 Hz, CH), 128.7 (C), 125.4 (q, J = 273 Hz, C), 123.3 (q, J = 34 Hz, C), 121.75 (CH), 118.0 (q, J = 4 Hz, CH), 117.6 (C), 110.3 (q, J = 4 Hz, CH), 107.5 (C), 59.8 (CH2), 14.9 (CH3); 19F NMR (376 MHz, DMSO-d6) δ −59.3; IR (neat) ν/cm−1: 3196 (m), 1667 (s), 1514 (m), 1440 (m

¹⁵N-Labelling and structure determination of adamantylated azolo-azines in solution

• Sergey L. Deev,
• Alexander S. Paramonov,
• Tatyana S. Shestakova,
• Igor A. Khalymbadzha,
• Oleg N. Chupakhin,
• Julia O. Subbotina,
• Oleg S. Eltsov,
• Pavel A. Slepukhin,
• Vladimir L. Rusinov,
• Alexander S. Arseniev and
• Zakhar O. Shenkarev

Beilstein J. Org. Chem. 2017, 13, 2535–2548, doi:10.3762/bjoc.13.250

• spin–spin interactions (see below). The 13C assignment procedure for 19-15N2, 20-15N2, and 21a,b-15N2 was aided by the data from a previous study of unlabelled derivatives of compound 19 [12]. The 13C-19F J-coupling constants (nJCF, Table 2) observed in the 1D 13C spectra facilitated the assignment of

• , 13C-15N and 13C-19F J-coupling constants (Hz) of the studied compoundsa. Supporting Information Supporting Information File 470: Detailed experimental procedures, the synthesis of labelled compounds, crystallographic information for 15a-15N2 and 15b-15N2, computational data, and 1D 1H, 13C and 2D 15N

One-pot three-component route for the synthesis of S-trifluoromethyl dithiocarbamates using Togni’s reagent

• Azim Ziyaei Halimehjani,
• Martin Dračínský and
• Petr Beier

Beilstein J. Org. Chem. 2017, 13, 2502–2508, doi:10.3762/bjoc.13.247

• using IR, 1H NMR, 13C NMR, 19F NMR and HRMS analysis. The dithiocarbamate moiety in S-trifluoromethyl dithiocarbamates appeared at 180–185 ppm in the 13C NMR spectra, while this group usually can be found at 190–200 ppm for S-alkyl dithiocarbamates [4][5][6][7][8][9][10][11][12]. Also the carbon of the

• CF3 group was observed at around 128 ppm as quartet with a coupling constant of ≈308 Hz. In addition, a singlet at −40 ppm in the 19F NMR spectra was assigned to the CF3 group. The one-pot reaction of benzylamine with CS2 and Togni's reagent I under optimal reaction conditions was also investigated

• , and 19F NMR spectra of all compounds. Acknowledgements We are grateful to the faculty of chemistry of Kharazmi University for supporting this work. This work was also supported by the Academy of Sciences of the Czech Republic (Research Plan RVO: 61388963) and Ministry of Education of the Czech

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• analogous reaction at room temperature gave Rf15CH2OTf in 22% yield. The triflates were white solids with some solubility in acetone. They were characterized by IR and NMR (1H, 13C{1H}, 19F{1H}) spectroscopy and microanalyses as summarized in the experimental section. The triflates were treated with NaI in

• , 67.46; S, 4.38; found: C, 21.44; H, 0.31; F, 67.21; S, 4.15; 1H NMR (500 MHz, acetone-d6) δ 5.55 (t, 3JHF = 13 Hz, 2H, CH2); 19F{1H} NMR (470 MHz, acetone-d6) δ −75.5 (s, 3F, SO2CF3), −81.7 (t, 4JFF = 10 Hz [60][61][62], 3F, CF3), −120.2 (m, 2F, CF2), −122.2 (m, 12F, 6CF2), −123.2 (m, 4F, 2CF2), −126.7

• , acetone-d6) δ 4.06 (t, 3JHF = 19 Hz, 2H, CH2); 19F{1H} NMR (470 MHz, acetone-d6) δ −81.6 (t, 4JFF = 10 Hz [60][61][62], 3F, CF3), −107.0 (m, 2F, CF2), −122.2 (m, 14F, 7CF2), −123.2 (m, 2F, CF2), −126.7 (m, 2F, CF2); 13C{1H} NMR (125 MHz, acetone-d6, partial) δ −3.8 (t, 2JCF = 25 Hz, CH2); IR (powder film

Diastereoselective Mannich reactions of pseudo-C₂-symmetric glutarimide with activated imines

• Tatsuya Ishikawa,
• Tomoko Kawasaki-Takasuka,
• Toshio Kubota and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2017, 13, 2473–2477, doi:10.3762/bjoc.13.244

• % yield as determined by 19F NMR (Table 1, entry 3). NaHMDS (Table 1, entry 4) or LiHMDS (Table 1, entry 5) instead of LDA worked properly affording 3a in a yield of 59 or 80%, respectively. The product 3a theoretically consists of 8 diastereomers and usually 2 isomers predominated with a couple of minor

Hydrolysis, polarity, and conformational impact of C-terminal partially fluorinated ethyl esters in peptide models

• Vladimir Kubyshkin and
• Nediljko Budisa

Beilstein J. Org. Chem. 2017, 13, 2442–2457, doi:10.3762/bjoc.13.241

• Vladimir Kubyshkin Nediljko Budisa Biocatalysis group, Institute of Chemistry, Technical University of Berlin, Müller-Breslau-Strasse 10, Berlin 10623, Germany 10.3762/bjoc.13.241 Abstract Fluorinated moieties are highly valuable to chemists due to the sensitive NMR detectability of the 19F

• background in spectroscopic observations of biological samples. This feature is especially beneficial for NMR applications because the sole stable fluorine isotope (19F) has the third largest magnetogyric ratio among the nuclei measured by NMR (after 3H and 1H hydrogen isotopes); as a result, 19F NMR

• experiments are remarkably sensitive [4]. Fluorine-containing groups can be incorporated into biopolymers by various approaches, including those that utilize biosynthesis [5][6][7], enzymatic conversion [8], chemical synthesis [9][10], and ligation reactions [11]. Depending on the research target, 19F NMR

Fluorination of some highly functionalized cycloalkanes: chemoselectivity and substrate dependence

• Attila Márió Remete,
• Melinda Nonn,
• Santos Fustero,
• Matti Haukka,
• Ferenc Fülöp and
• Loránd Kiss

Beilstein J. Org. Chem. 2017, 13, 2364–2371, doi:10.3762/bjoc.13.233

• 60 F254 was purchased from Merck. The NMR spectra were acquired at room temperature on a Bruker Avance 400 spectrometer with 11.75 T magnetic field strength (1H frequency: 400.13 MHz, 19F frequency: 376.50 MHz, 13C frequency: 100.76 MHz, respectively) in CDCl3 or DMSO-d6 solution, using the deuterium

• signal of the solvent to lock the field. The 1H and 13C chemical shifts are given relative to TMS and 19F chemical shifts are referenced to CFCl3 (0.00 ppm). General procedures for fluorination Method A: To a solution of dihydroxylated compound (0.50 mmol) in 10 mL anhydrous CH2Cl2 under an Ar atmosphere

Homologated amino acids with three vicinal fluorines positioned along the backbone: development of a stereoselective synthesis

• Raju Cheerlavancha,
• Ahmed Ahmed,
• Yun Cheuk Leung,
• Aggie Lawer,
• Qing-Quan Liu,
• Marina Cagnes,
• Hee-Chan Jang,
• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2017, 13, 2316–2325, doi:10.3762/bjoc.13.228

• ketones [31]. However, 1H NMR and 19F NMR analysis of the crude reaction mixture revealed that the only identifiable product was the undesired gem-difluorinated compound 25 (Scheme 2), which was obtained along with a significant amount of unreacted starting material 21a (see Supporting Information File 1

• -scale final fluorination reaction was attempted (Scheme 3) because this was anticipated to converge some of the compounds into a simpler product mixture. Analysis of the crude reaction mixture by 19F NMR revealed that the desired product 29 may have been formed in small quantity. However, there was

• final compounds, which were of low molecular weight and very polar. Nevertheless, the first synthesis of a δ-amino acid containing three vicinal fluorines on the backbone had been successfully completed. The all-syn target 6b was then obtained in a similar fashion from 40b (Scheme 4). The 1H and 19F NMR

Comparative profiling of well-defined copper reagents and precursors for the trifluoromethylation of aryl iodides

• Peter T. Kaplan,
• Jessica A. Lloyd,
• Mason T. Chin and
• David A. Vicic

Beilstein J. Org. Chem. 2017, 13, 2297–2303, doi:10.3762/bjoc.13.225

• , we monitored the reactions of the iodotoluenes by quantitative 19F NMR spectroscopy. Using the same solvent systems employed for the reactions in Figure 2, conversions were measured over a 22 hour period (Figure 3). In this case, [(SIMes)Cu(CF3)] performed just as well as the [(phen)Cu(CF3

• by 1H NMR and 19F NMR for purity. Copper salt precursors were purchased from Sigma-Aldrich. Trimethyl(trifluoromethyl)silane (99% purity) was purchased from SynQuest Labs, Inc. and used without further purification. All other chemicals were verified by 1H NMR for purity and used without further

• glovebox. The quantitative NMR analyses were accomplished using a Bruker Ascend 400 MHz spectrometer by 19F NMR spectra referenced to internal standard of fluorobenzene. Solution 1H NMR spectra were recorded at ambient temperature on a Bruker Ascend 400 MHz spectrometer and referenced to residual proton

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• TFEO-ZnPc 4 and fluorinated polymer 22 were condensed by a click reaction between azide and alkyne groups (Scheme 8). The graft ratio of the TFEO-ZnPc-supported fluoropolymer was calculated from the area ratio of 19F NMR, and the resulting fluorinated copolymers showed different grafting ratios (from