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Search for "trifluoroacetic acid" in Full Text gives 299 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Oxetanes: formation, reactivity and total syntheses of natural products

  • Peter Gabko,
  • Martin Kalník and
  • Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

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  • (necessary for aromatisation) are promoted by trifluoroacetic acid under similarly mild conditions. In case of the pyrrole synthesis, the same precursors are treated with a primary amine in DCM and the reaction mixture is heated at 40 °C for 12–24 h. As 1,4-addition also takes place during this process, two
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Published 27 Jun 2025

Studies on the syntheses of β-carboline alkaloids brevicarine and brevicolline

  • Benedek Batizi,
  • Patrik Pollák,
  • András Dancsó,
  • Péter Keglevich,
  • Gyula Simig,
  • Balázs Volk and
  • Mátyás Milen

Beilstein J. Org. Chem. 2025, 21, 955–963, doi:10.3762/bjoc.21.79

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  • 21 under extremely harsh conditions (100 °C, 130 bar), followed by N-acetylation gave a mixture of diastereomeric racemates 22, which was cyclized to a diastereomeric mixture of β-carboline derivatives 23. Heating of 23 in pivalic acid in the presence of a catalytic amount of trifluoroacetic acid
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Published 20 May 2025

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

  • Rémy B. Teponno,
  • Sara R. Noumeur and
  • Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

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  • Agilent 1100 series preparative HPLC system [ChemStation software (Rev. B.04.03 SP1); binary pump system; column: Kinetex 5u RP C18, dimensions 250 × 21.20 mm; mobile phase: ACN + 0.05% trifluoroacetic acid (TFA) and water + 0.05% TFA; flow rate: 20 mL/min; diode array UV detector; 226 fraction collector
  • software (Rev. B.04.03 SP1); binary pump system; column: Kinetex 5u RP C18, dimensions 250 × 21.20 mm; mobile phase: ACN + 0.05% trifluoroacetic acid (TFA) and water + 0.05% TFA; flow rate 20 mL/min; diode array UV detector; 226 fraction collector. A gradient from 47 to 72% solvent B in 50 min was used
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Published 17 Mar 2025

Cryptophycin unit B analogues

  • Thomas Schachtsiek,
  • Jona Voss,
  • Maren Hamsen,
  • Beate Neumann,
  • Hans-Georg Stammler and
  • Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

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  • , HOAt, N,N-dimethylformamide 0 °C for 2 h and at rt for 20 min, 11%; f) Grubbs II catalyst, CH2Cl2, reflux, 3 h, 84%; g) TFA, H2O, CH2Cl2, 0 °C to rt, 5 h, 91%. EDC·HCl = 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride; DMAP = 4-(dimethylamino)pyridine; TFA = trifluoroacetic acid; HOAt = 1
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Published 07 Mar 2025

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

  • Thomas Brandt,
  • Pascal Lentes,
  • Jeremy Rudtke,
  • Michael Hösgen,
  • Christian Näther and
  • Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

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  • . Using diphenylamine as a more electron-rich amine resulted in the formation of diphenylamino-substituted N-acetyl diazocine 20 in a significantly lower yield of 25% starting from the bromide 2 and 47% starting from the iodo precursor 3 (Table 5). Deprotection of carbamate 19 with trifluoroacetic acid
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Published 04 Mar 2025

Synthesis of electrophile-tethered preQ1 analogs for covalent attachment to preQ1 RNA

  • Laurin Flemmich and
  • Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 483–489, doi:10.3762/bjoc.21.35

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  • by displacement of the mesyl group to give a six-membered cyclic carbamate, a reactivity that has been described earlier [34]. Thus, care was taken to quickly isolate compound 14 and use it immediately in the next step. Deblocking of the secondary amine by treatment with trifluoroacetic acid afforded
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Published 04 Mar 2025

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

  • Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

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  • activity in electrocatalytic HER [123]. Although free base corrole ligands demonstrated activity in HER, they were unstable in trifluoroacetic acid (TFA), a common proton source, leading to rapid degradation during catalysis. Subsequently, the same group introduced metal-free xanthene-bridged biscorroles
  • were further explored using 18 (H2TPP) as a catalyst, Fc as an external reductant, DCE as a solvent, and two different compounds as proton sources: tetrakis(pentafluorophenyl)boric acid (HTB) and trifluoroacetic acid (TFA) [118]. After HTB was added to 18 (H2TPP) in 1:2.5 molar ratio, the Soret band in
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Published 27 Nov 2024

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

  • Anastasia I. Ershova,
  • Sergey V. Fedoseev,
  • Konstantin V. Lipin,
  • Mikhail Yu. Ievlev,
  • Oleg E. Nasakin and
  • Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

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  • 511 nm), in the region of solvents with medium polarity. Protonation of the dimethylamino group was additionally confirmed by titration of pyrindane 1i in toluene using trifluoroacetic acid (see Figure S2, Supporting Information File 1). According to the data obtained, an increasing amount of acid
  • caused a blue shift of the maximum at 511 nm, and a new maximum in the region of 380–400 nm appeared in the absorption spectra. The intensity of the short-wavelength band also increased upon addition of trifluoroacetic acid. At the same time, a second band centered at 440 nm also appeared in the emission
  • , compound 1i could form the salt 1iH+. Therefore, the effect of acid vapors on the solid-state emission was studied. It was found that pyrindane 1i was sensitive to formic and trifluoroacetic acid vapors. As a result of protonation, a significant blue shift of the emission maximum from 762 nm down to 493 nm
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Published 19 Nov 2024

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

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  • electrocatalytic hydrogen evolution reactions, a proton source is needed [11]. In this context, trifluoroacetic acid is very frequently chosen as the proton source, because it is a strong acid but just not strong enough to destroy (demetallate) the Ni porphyrin [10]. Covalent attachment of acids facilitates proton
  • transfer and increases the efficiency [12]. Three conditions should be met for the target porphyrins of this study. 1. The acid covalently bound to the porphyrin should have an acid strength similar to trifluoroacetic acid. 2. The length of the tether with which the acid group is bound should be sufficient
  • -synthetic modification of this porphyrin proved to be difficult. Therefore, we have integrated the acid group into the aldehyde component of the Rothemund reaction to prepare the target porphyrin. In initial tests, we have established that trifluoroacetic acid can be replaced by perfluorinated alkyl
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Published 15 Nov 2024

5th International Symposium on Synthesis and Catalysis (ISySyCat2023)

  • Anthony J. Burke and
  • Elisabete P. Carreiro

Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227

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  • in MeOH at room temperature with a short reaction time. Some of them were further functionalized with a 1,2,3-triazole ring via copper-catalyzed azide–alkyne cycloaddition (CuAAC) and deprotected with trifluoroacetic acid. Several hybrids were evaluated against six cancer cell lines, displaying GI50
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Published 28 Oct 2024

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

  • Nian Li,
  • Ruzal Sitdikov,
  • Ajit Prabhakar Kale,
  • Joost Steverlynck,
  • Bo Li and
  • Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

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  • disclosed a similar trifluoromethylation of arenes under photoelectrochemical reaction conditions but without the addition of a photocatalyst, using trifluoroacetic acid as the CF3 source (Scheme 47b) [71]. This alternative approach further underscores the versatility and applicability of
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Published 09 Oct 2024

Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols

  • Smaher E. Butt,
  • Konrad Kepski,
  • Jean-Marc Sotiropoulos and
  • Wesley J. Moran

Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209

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  • that the transition state was stabilized by 4.1 kcal·mol−1 by an extra molecule of trifluoroacetic acid. A similar stabilizing interaction was not identified in this case with 3a, despite significant effort, but it cannot be ruled out. The cyclization of 9 was shown to be possible by attack of the
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Published 30 Sep 2024

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

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  • derivative 2k, and the estrone derivative 2l were also successfully bis-functionalized. Some products appeared to be sensitive during purification by chromatography on silica gel. Suspecting acid sensitivity, compound 2a was treated with trifluoroacetic acid to confirm this hypothesis (Scheme 3). The product
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Published 26 Sep 2024

Natural resorcylic lactones derived from alternariol

  • Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

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Published 30 Aug 2024

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

  • Shakeel Alvi and
  • Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

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  • –80%) along with their preliminary photophysical (absorption, emission and time resolved fluorescence lifetime) properties. The condensation reaction for assembling the required DPMs were catalyzed with trifluoroacetic acid (TFA) at 0 °C to room temperature (rt), and the stable dipyrromethanes were
  • truxenes with freshly distilled pyrrole using trifluoroacetic acid (TFA) as an acidic catalyst afforded the anticipated DPM-appended truxene derivatives (14, 16 and 18) in good yields (60–80%). All the newly prepared DPM-linked truxene-hybrid molecules as well as the intermediate acetylated truxene
  • in freshly distilled pyrrole with different amounts (5 equiv for 14, 10 equiv for 16, and 15 equiv for 18). Then trifluoroacetic acid (TFA, 0.1 equiv for 14, 0.2 equiv for 16 and 0.3 equiv for 18) was added to the reaction mixture, and the resulting mixture was stirred at 0 °C (16) or 0 °C to rt (14
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Published 29 Aug 2024

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

  • Kateryna V. Dil and
  • Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

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  • ). However, increasing acidity and using trifluoroacetic acid (Table 1, entry 17) did not improve the overall yield. We also tried microwave activation conditions since this is a known technique for reactions of this type [32], but unfortunately, we did not find any improvement in the yield (Table 1, entry
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Published 27 Aug 2024

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

  • Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

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  • photocatalyst TAC+. The electrolysis was carried out at a constant cell potential of 1.5 V under white light irradiation. The carbonyl compound 144 was initially treated with tert-butyl carbazate (145) in acetonitrile in the presence of molecular sieves, followed by the addition of trifluoroacetic acid (TFA) to
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Published 14 Aug 2024

Development of a flow photochemical process for a π-Lewis acidic metal-catalyzed cyclization/radical addition sequence: in situ-generated 2-benzopyrylium as photoredox catalyst and reactive intermediate

  • Masahiro Terada,
  • Zen Iwasaki,
  • Ryohei Yazaki,
  • Shigenobu Umemiya and
  • Jun Kikuchi

Beilstein J. Org. Chem. 2024, 20, 1973–1980, doi:10.3762/bjoc.20.173

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  • generated in the flow reaction system through the intramolecular cyclization of ortho-carbonyl alkynylbenzene derivatives by the π-Lewis acidic metal catalyst AgNTf2 and the subsequent proto-demetalation with trifluoroacetic acid. The 2-benzopyrylium intermediates underwent further photoreactions with
  • intramolecular cyclization followed by proto-demetalation with trifluoroacetic acid (TFA). In catalytic cycle II, photoexcitation of the generated 2-benzopyrylium intermediates A under light irradiation facilitates single-electron transfer (SET) from benzyltrimethylsilane derivatives 2 as the donor molecule
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Published 13 Aug 2024

Novel oxidative routes to N-arylpyridoindazolium salts

  • Oleg A. Levitskiy,
  • Yuri K. Grishin and
  • Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2024, 20, 1906–1913, doi:10.3762/bjoc.20.166

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  • intermediate (i.e., the diarylamines’ radical cation) and indicates the dominance of the intramolecular cyclization over the intermolecular C–N coupling process. Oxidation of diarylamines in the presence of an excess of trifluoroacetic acid gave no targeted pyridoindazolium salts, whereas the amount of
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Published 07 Aug 2024

Electrochemical radical cation aza-Wacker cyclizations

  • Sota Adachi and
  • Yohei Okada

Beilstein J. Org. Chem. 2024, 20, 1900–1905, doi:10.3762/bjoc.20.165

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  • due to the increased conductivity of the electrolyte solution (Table 1, entry 1). The reaction did not take place without electricity and most of the starting material was recovered (Table 1, entry 3). The addition of trifluoroacetic acid (TFA) was advantageous in terms of the reproducibility, which
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Published 05 Aug 2024

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

  • Cristina Martini,
  • Muhammad Idham Darussalam Mardjan and
  • Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

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  • reaction conditions. The authors performed the optimization study using 5-HMF (23), 2-aminothiazole (24) and tert-butyl isocyanide (5, Scheme 10). Inspired by a procedure reported by Demjén et al. [37], they found the best conditions using EtOH as a green solvent, trifluoroacetic acid (TFA, 20 mol %) or Yb
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Published 01 Aug 2024

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

  • Guoqing Cheng and
  • Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

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  • @(12,2)-SWNT complexes. Chemical structures of Cu-tethered tetragonal nanobrackets 1a and 1b. Synthesis of nanobracket 4. Reaction conditions: i) XPhos Pd G2, XPhos, B2(OH)4, KOAc, EtOH, 80 °C, 2 h; ii) Br-Ar-Br, K2CO3, tetrahydrofuran (THF)/toluene, 80 °C, 16 h; iii) trifluoroacetic acid (TFA), pyrrole
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Published 05 Jun 2024

The Ugi4CR as effective tool to access promising anticancer isatin-based α-acetamide carboxamide oxindole hybrids

  • Carolina S. Marques,
  • Aday González-Bakker and
  • José M. Padrón

Beilstein J. Org. Chem. 2024, 20, 1213–1220, doi:10.3762/bjoc.20.104

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  • conditions (120 ºC, 30 minutes) (Scheme 3). Resourcefulness of the Ugi4CR and preliminary SAR studies [16] lead us to synthesize a third library of oxindole derivatives, using trifluoroacetic acid (TFA), under mild reaction conditions, to afford the corresponding α-acetamide carboxamide isatin hybrids 8 from
  • -acetamide carboxamide isatin hybrids 8 easy accessed via deprotection reaction on the Ugi-adducts 5 and 7. TFA: trifluoroacetic acid. Supporting Information Supporting Information File 56: Experimental procedures, analytical data, NMR spectra and biological assays. Funding C. S. M. thanks the Norma
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Published 27 May 2024

Introduction of peripheral nitrogen atoms to cyclo-meta-phenylenes

  • Koki Ikemoto and
  • Hiroyuki Isobe

Beilstein J. Org. Chem. 2024, 20, 1207–1212, doi:10.3762/bjoc.20.103

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  • -doped CMPs. Thus, when trifluoroacetic acid (TFA) was added to a solution of 3a in chloroform, bathochromic shifts in UV spectra were observed, indicating protonation-induced changes in the electronic properties [10]. Because of the weakly acidic nature of pyridinic nitrogen atoms, an excess amount of
  • on the 0.0067 e·Å−3 isosurface for the electron density. Response towards acid treatment with nitrogen-doped CMPs. (a) Absorption spectra of 3a (CHCl3, 2.3 × 10−6 M) in the absence (black) and presence of trifluoroacetic acid (green: 4.3 × 10−2 M, blue: 2.1 × 10−1 M, red: 4.2 × 10−1 M). (b
  • ) Absorption spectra of 6 (CHCl3, 1.9 × 10−6 M) in the absence (black) and presence of trifluoroacetic acid (green: 4.3 × 10−2 M, blue: 2.1 × 10−1 M, red: 4.2 × 10−1 M). Syntheses of 3a and 3b. Supporting Information Supporting Information File 50: Experimental and copies of spectra. Supporting Information
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Published 24 May 2024

Cofactor-independent C–C bond cleavage reactions catalyzed by the AlpJ family of oxygenases in atypical angucycline biosynthesis

  • Jinmin Gao,
  • Liyuan Li,
  • Shijie Shen,
  • Guomin Ai,
  • Bin Wang,
  • Fang Guo,
  • Tongjian Yang,
  • Hui Han,
  • Zhengren Xu,
  • Guohui Pan and
  • Keqiang Fan

Beilstein J. Org. Chem. 2024, 20, 1198–1206, doi:10.3762/bjoc.20.102

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  • analyzed on a Waters HPLC system equipped with a 1525 pump and a 2487 dual λ UV detector using an Agilent ZORBAX SB-C18 reversed-phase column (5 μm, 4.6 × 250 mm) or a SilGreen C18AB reversed-phase column (5 μm, 4.6 × 250 mm). The elution solvents were water with 0.1% (v/v) trifluoroacetic acid (solvent A
  • ) and acetonitrile with 0.1% (v/v) trifluoroacetic acid (solvent B). A 20-min linear gradient from 25% (v/v) to 100% (v/v) solvent B was used with a flow rate of 1.0 mL⋅min−1. Absorbance at 266 and 313 nm was monitored. For SOD quench experiments, the reaction mixtures were analyzed on an Agilent 1260
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Published 23 May 2024
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