Halogen-bonding-induced diverse aggregation of 4,5-diiodo-1,2,3-triazolium salts with different anions

• Xingyu Xu,
• Shiqing Huang,
• Zengyu Zhang,
• Lei Cao and
• Xiaoyu Yan

Beilstein J. Org. Chem. 2020, 16, 78–87, doi:10.3762/bjoc.16.10

• triazolium salts show diverse aggregation via halogen bonding between C–I bonds and anions. Triazolium with halide anions exists as a tetramer with saddle conformation. Triazolium tetrafluoroborate exists as a trimer with Chinese lantern shape conformation. Triazolium trifluoroacetate and acetate exist as

• compounds show XB interactions between the triazolium moiety and anions, and different aggregations are formed. Triazolium with halide anions exists as tetramers with saddle conformation. Triazolium tetrafluoroborate exists as trimer with Chinese lantern shape conformation. Triazolium trifluoroacetate and

• -triazolium salts with different anions. When the anion is chloride, bromide or iodide, the crystal is a tetramer. Strong XB was observed in these forms. When the anion is changed to tetrafluoroborate, it takes Chinese lantern shape as a trimer. Triazolium trifluoroacetate and acetate exist as a dimer, while

Construction of trisubstituted chromone skeletons carrying electron-withdrawing groups via PhIO-mediated dehydrogenation and its application to the synthesis of frutinone A

• Qiao Li,
• Chen Zhuang,
• Donghua Wang,
• Wei Zhang,
• Rongxuan Jia,
• Fengxia Sun,
• Yilin Zhang and
• Yunfei Du

Beilstein J. Org. Chem. 2019, 15, 2958–2965, doi:10.3762/bjoc.15.291

• generation of some unidentified byproducts. A solvent screening identified DMF to be the most appropriate solvent for this transformation (Table 1, entries 1–9). Other commonly employed oxidants, including phenyliodine(III) diacetate (PIDA), phenyliodine(III) bis(trifluoroacetate) (PIFA), and iodylbenzene

AgNTf₂-catalyzed formal [3 + 2] cycloaddition of ynamides with unprotected isoxazol-5-amines: efficient access to functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives

• Ziping Cao,
• Jiekun Zhu,
• Li Liu,
• Yuanling Pang,
• Laijin Tian,
• Xuejun Sun and
• Xin Meng

Beilstein J. Org. Chem. 2019, 15, 2623–2630, doi:10.3762/bjoc.15.255

• AgOTF (silver trifluoroacetate) salts can catalyze the proceeding of the reaction at 80 °C, affording the desired pyrrole 10aa in 42% and 28% yields (Table 1, entries 2 and 3), respectively. The hydrolytic product 11 was also obtained in 55% yield when AgOTF was used as the catalyst. Other silver

A review of the total syntheses of triptolide

• Xiang Zhang,
• Zaozao Xiao and
• Hongtao Xu

Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194

• trifluoroacetate 60 by a known electrophilic substitution procedure that was developed by Tahara and co-workers [64]. Curtius rearrangement of 60 gave an isocyanate intermediate, which was reduced with LiAlH4 followed by reductive amination affording tertiary amine intermediate 61. Oxidation of 61 to its

The cyclopropylcarbinyl route to γ-silyl carbocations

• Xavier Creary

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

• cyclopropylcarbinyl alcohol, which was available from methyl 2-diazopropanoate by a process completely analogous to the synthesis of the phenyl analog 17. The mesylate derivative was too reactive for rates to be measured and hence the trifluoroacetate derivative 48 was studied. Acetolysis gave the acetate 50 along

• with a smaller amount of methylcyclobutene (51, Scheme 10). This reactivity is completely analogous to that seen in the phenyl and hydrogen analogs 19 and 31, i.e., a mechanistic scheme involving the γ-trimethylsilyl-stabilized cation 52 is likely. The isomeric trifluoroacetate 49 (shown in Table 1

• ) gives methylcyclobutene (51) (68%) as the major acetolysis product, along with minor products that are identical to those previously reported [52] in solvolysis of the trifluoroacetate derivative of (1r,3r)-1-methyl-3-(trimethylsilyl)cyclobutanol. As in the case of mesylate 32, the γ-trimethylsilyl

Novel (2-amino-4-arylimidazolyl)propanoic acids and pyrrolo[1,2-c]imidazoles via the domino reactions of 2-amino-4-arylimidazoles with carbonyl and methylene active compounds

• Victoria V. Lipson,
• Tetiana L. Pavlovska,
• Nataliya V. Svetlichnaya,
• Anna A. Poryvai,
• Nikolay Yu. Gorobets,
• Erik V. Van der Eycken,
• Irina S. Konovalova,
• Svetlana V. Shiskina,
• Alexander V. Borisov,
• Vladimir I. Musatov and
• Alexander V. Mazepa

Beilstein J. Org. Chem. 2019, 15, 1032–1045, doi:10.3762/bjoc.15.101

• structure of 1-([1,1'-biphenyl]-4-yl)-5-oxo-7-phenyl-6,7-dihydro-5H-pyrrolo[1,2-c]imidazol-3-aminium 2,2,2-trifluoroacetate 9i according to X-ray diffraction data. Thermal ellipsoids of atoms are shown at 50% probability level. Molecular structure of 3-(2-amino-4-phenyl-1H-imidazol-5-yl)-3-(p-tolyl

Synthesis and selected transformations of 2-unsubstituted 1-(adamantyloxy)imidazole 3-oxides: straightforward access to non-symmetric 1,3-dialkoxyimidazolium salts

• Grzegorz Mlostoń,
• Małgorzata Celeda,
• Katarzyna Urbaniak,
• Marcin Jasiński,
• Vladyslav Bakhonsky,
• Peter R. Schreiner and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2019, 15, 497–505, doi:10.3762/bjoc.15.43

• trifluoroacetate (Scheme 7). Unexpectedly, this test experiment, performed with 7a at room temperature, led after 24 h not to the expected, symmetric 1,3-di(adamantyloxy)imidazolium salt 13h but to the trifluoroacetate of the starting material, i.e., compound 14, formed side by side with adamantan-1-ol. Apparently

• obtained in high yields. Attempted adamantylation of a 1-(adamantyloxy)imidazole 3-oxide with 1-bromoadamantane or adamantan-1-yl trifluoroacetate was unsuccessful. Nevertheless, the corresponding symmetric 1,3-di(adamantyloxy)imidazolium bromide was obtained in the reaction of adamantyloxyamine with

• trifluoroacetate (CF3CO2Ad) was prepared following a known protocol [38]. 1-Bromoadamantane, 1-bromopentane (12a) and 1-bromododecane (12b) were commercial reagents used in the studied reactions with no additional purification. General procedure for the preparation of imidazole 3-oxides 7 (procedure A): A solution

A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

• Ilya V. Taydakov,
• Yuliya M. Kreshchenova and
• Ekaterina P. Dolotova

Beilstein J. Org. Chem. 2018, 14, 3106–3111, doi:10.3762/bjoc.14.290

• ]. This compound was first obtained by Reid and Calvin in 1950 [15] by Claisen condensation of 2-acetylthiophene and ethyl trifluoroacetate in the presence of NaOEt in Et2O (Scheme 1). The purification procedure was laborious and included copper chelate precipitation and its subsequent acid decomposition

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• trichloroacetate and trifluoroacetate anions 47b,c. Following this method, various aromatic aldehydes bearing electron-withdrawing or donating groups (-NO2, -Cl, -OMe, -Me) 7 have been used to prepare the desired products in 85–95% yields. Aliphatic aldehydes produced complex mixtures of products using these

Unprecedented nucleophile-promoted 1,7-S or Se shift reactions under Pummerer reaction conditions of 4-alkenyl-3-sulfinylmethylpyrroles

• Takashi Go,
• Akane Morimatsu,
• Hiroaki Wasada,
• Genzoh Tanabe,
• Osamu Muraoka,
• Yoshiharu Sawada and
• Mitsuhiro Yoshimatsu

Beilstein J. Org. Chem. 2018, 14, 2722–2729, doi:10.3762/bjoc.14.250

• TFAA to form sulfonium salt 14, which is characterised by an intramolecular double bond [34][35]. A less substituted double bond easily approaches the sulfonium ion and undergoes an addition reaction to produce intermediate 15. The trifluoroacetate anion attacks the posterior side of the α-carbon of

Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepine derivatives by [3⁺ + 2]-cycloaddition/rearrangement reactions

• Lin-bo Luan,
• Zi-jie Song,
• Zhi-ming Li and
• Quan-rui Wang

Beilstein J. Org. Chem. 2018, 14, 1826–1833, doi:10.3762/bjoc.14.155

• -triazolodiazepinium salts 10, the anion AlCl3(OAc)− in the initially formed products was replaced with a suitable counter ion such as chloride, trifluoroacetate and picrate, which proved to be a useful way to facilitate the isolation of the target salts 10. In order to further explore the scope and generality in view

Synthesis of trifluoromethylated 2H-azirines through Togni reagent-mediated trifluoromethylation followed by PhIO-mediated azirination

• Jiyun Sun,
• Xiaohua Zhen,
• Huaibin Ge,
• Guangtao Zhang,
• Xuechan An and
• Yunfei Du

Beilstein J. Org. Chem. 2018, 14, 1452–1458, doi:10.3762/bjoc.14.123

• and phenyliodine bis(trifluoroacetate) (PIFA) were tested, but the results indicated that they were ineffective to further improve the yields (Table 1, entries 11 and 12). With the optimized conditions in hand, we next explored the substrate scope for this newly established one-pot oxidative

Rapid transformation of sulfinate salts into sulfonates promoted by a hypervalent iodine(III) reagent

• Elsa Deruer,
• Vincent Hamel,
• Samuel Blais and
• Sylvain Canesi

Beilstein J. Org. Chem. 2018, 14, 1203–1207, doi:10.3762/bjoc.14.101

• ). To verify our hypothesis tosyl-sulfinate 1 was treated with iodanes such as sodium periodate (NaIO4), Dess-Martin periodinane (DMP) [33], 2-iodoxybenzoic acid (IBX) [34], (diacetoxyiodo)benzene (DIB), phenyliodine(III) bis(trifluoroacetate) (PIFA) in the presence of methanol. (III)-Iodanes and (V

Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

• Toshifumi Dohi,
• Shohei Ueda,
• Kosuke Iwasaki,
• Yusuke Tsunoda,
• Koji Morimoto and
• Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

• ), phenyliodine(III) bis(trifluoroacetate) (PIFA), and iodosobenzene, has since become a popular choice for benzylic oxidations, which further expanded the scope and availability of methods for direct C–H functionalization and several coupling reactions [42][43][44][45][46][47][48][49][50]. As such, we reported

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

• was paid on trifluoroacetates. Trifluoroacetate is readily available and one of the cheapest and most convenient sources of the trifluoromethylation for both industrial and medicinal purposes. In 2011, a practical and ligand-free Cu-catalyzed decarboxylative trifluoromethylation of aryl iodides was

• reported by the group of Li and Duan, with sodium trifluoroacetate as the trifluoromethyl source and using Ag2O as a promoter (Scheme 5) [17]. Subsequently, Beller and co-workers [18] finished a copper-catalyzed trifluoromethylation of aryl iodides with inexpensive methyl trifluoroacetate (MTFA) (Scheme 6

• aromatic trifluoromethylation step. The attractive prospect of trifluoroacetate as the trifluoromethyl source for the preparation of trifluoromethylarenes prompted the investigation of the mechanism of this reaction. A mechanistic study indicated that CuCF3 was formed by decarboxylation of the

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

• persulfate by hypervalent iodine oxidants such as iodobenzene diacetate (PIDA, Scheme 28) [49], or iodobenzene bis(trifluoroacetate) (PIFA) [50]. Fu and co-workers proposed the reaction mechanism depicted in Scheme 28. PIDA reacted with CF3SO2Na under heating conditions to produce two radicals: CF3• along

• phenyliodine bis(trifluoroacetate) (PIFA) instead of tert-butyl hydroperoxide as the oxidant in hexafluoroisopropanol (HFIP) at room temperature [71]. In order to obtain good results for this transformation, it should be noted that the electron-donating nature of the aromatic substituents was a crucial point

• -workers reported the synthesis of trifluoromethylated coumarin 71 and flavone 72 with CF3SO2Na (2 equiv), the hypervalent iodine F5-PIFA (pentafluorophenyliodine bis(trifluoroacetate)) (2 equiv) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ, 0.6 equiv). The trifluoromethylated compounds were obtained

Base-promoted isomerization of CF₃-containing allylic alcohols to the corresponding saturated ketones under metal-free conditions

• Yoko Hamada,
• Tomoko Kawasaki-Takasuka and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2017, 13, 1507–1512, doi:10.3762/bjoc.13.149

• trifluoroacetate at −80 °C, a Horner–Wadsworth–Emmons reagent [17] activated by LiBr and Et3N [18][19][20] was introduced to this solution at room temperature, leading to the formation of (E)-6 after the NaBH4 reduction of the resultant products (see Supporting Information File 1 for the detailed procedure). As

Regioselective (thio)carbamoylation of 2,7-di-tert-butylpyrene at the 1-position with iso(thio)cyanates

• Anna Wrona-Piotrowicz,
• Marzena Witalewska,
• Janusz Zakrzewski and
• Anna Makal

Beilstein J. Org. Chem. 2017, 13, 1032–1038, doi:10.3762/bjoc.13.102

• sterically hindered pyrene 1-position, whereas the bulkier protonated acetyl trifluoroacetate (the postulated electrophile in the examined Friedel–Crafts acylation) attacks sterically the less hindered 4-position. Conclusion We found that triflic acid-promoted (thio)carbamoylation of 2 with aliphatic iso

A strategic approach to [6,6]-bicyclic lactones: application towards the CD fragment of DHβE

• Tue Heesgaard Jepsen,
• Emil Glibstrup,
• François Crestey,
• Anders A. Jensen and
• Jesper Langgaard Kristensen

Beilstein J. Org. Chem. 2017, 13, 988–994, doi:10.3762/bjoc.13.98

• , MeOH, DCM) and was found to be unstable on silica. Thus, all attempts to purify the material through column chromatography or preparative TLC led to decomposition of the material. Also an attempted isolation of the amine as its hydrochloride or trifluoroacetate failed. Finally, the [6,6]-bicyclic

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

• reactor at 25 °C for a residence time of 3 min to get the trifluoroacetate, which further reacts with triethylamine in a PFA coil (10 mL) at 100 °C for 5 min to give the final drug molecule. By using Vapourtec V-3 peristaltic pumps, the authors are able to achieve a constant fluid flow rate. Maintaining

Symmetry-based approach to oligostilbenoids: Rapid entry to viniferifuran, shoreaphenol, malibatol A, and diptoindonesin G

• Youngeun Jung,
• Dileep Kumar Singh and
• Ikyon Kim

Beilstein J. Org. Chem. 2016, 12, 2689–2693, doi:10.3762/bjoc.12.266

• -dimethoxybenzaldehyde, and 3,5-dimethoxybenzyl alcohol under the influence of either I2/silver trifluoroacetate or N-iodosuccinimide afforded 1 [32][33][34], 2 [35], and 7 [36][37], respectively (Scheme 2). The hydroxy group of 7 was protected as an acetate, providing 3 in 96% yield. Sonogashira coupling of the

Unusual reactions of diazocarbonyl compounds with α,β-unsaturated δ-amino esters: Rh(II)-catalyzed Wolff rearrangement and oxidative cleavage of N–H-insertion products

• Valerij A. Nikolaev,
• Jury J. Medvedev,
• Olesia S. Galkina,
• Ksenia V. Azarova and
• Christoph Schneider

Beilstein J. Org. Chem. 2016, 12, 1904–1910, doi:10.3762/bjoc.12.180

• catalyst and its ligands on the efficiency of the processes studied, non-fluorinated rhodium carboxylates (Rh2L4; L = OAc, Oct, Piv) and catalysts with trifluoroacetate or perfluorobutyrate ligands [Rh2L4; L = CF3CO2 (tfa), C3F7CO2 (pfb)] were used in this research. Results and Discussion In the beginning

Three-component synthesis of highly functionalized aziridines containing a peptide side chain and their one-step transformation into β-functionalized α-ketoamides

• Lena Huck,
• Juan F. González,
• Elena de la Cuesta and
• J. Carlos Menéndez

Beilstein J. Org. Chem. 2016, 12, 1772–1777, doi:10.3762/bjoc.12.166

• ether function existent in aziridine derivatives 2 because of the presence of the 2-methoxy substituent would furnish oxonium species 7 via a Neber reaction. Its O-demethylation by the trifluoroacetate anion would yield compound 8, whose amino group would finally be trifluoroacetylated by the methyl

• trifluoroacetate liberated in the previous step, to give 6. Alternatively, loss of a molecule of methanol from starting compound 2 would lead to intermediate 5 (see Scheme 3), whose reaction with trifluoroacetic acid would furnish 9. Neber-type chemistry would afford the oxonium species 10, which would finally be

Methylpalladium complexes with pyrimidine-functionalized N-heterocyclic carbene ligands

• Dirk Meyer and
• Thomas Strassner

Beilstein J. Org. Chem. 2016, 12, 1557–1565, doi:10.3762/bjoc.12.150

• trifluoroacetato ligands occurs [29], which is present in the solution in large excess. This potential intermediate of the catalytic cycle, the [(pym)^(NHC-R)PdII(CH3)(CF3COO)]-complex 13 (with R = 2,6-diisopropylphenyl), could be synthesized by the reaction of complex 11 with silver trifluoroacetate (Scheme 2

• methane is converted into methyl trifluoroacetate catalyzed by a Pd(II) complex. To examine if a methylated Pd(II) complex like 13 can be an intermediate of this reaction, potassium peroxodisulfate and sodium trifluoroacetate were added to a solution of 13 in DMSO-d6 or CDCl3. Analyzing the solution we

• could confirm the formation of methyl trifluoroacetate and a ‘methyl free’ Pd(II) complex. This complex showed similar NMR spectra like the bistrifluoroacetate complex 14 (Scheme 3), which was prepared by the reaction of the corresponding dichloro complex [34] with silver trifluoroacetate for comparison

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• potential of 20 kV. Dichloromethane solutions containing 1 g L−1 of a sample, 10 g L−1 of dithranol, and 1 g L−1 of sodium trifluoroacetate were mixed at the ratio of 1:1:1, and 1 mL aliquot of this mixture was deposited onto a sample target plate. Gel permeation chromatography (GPC) was measured on a JASCO