Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• -naphthodiyne, generated in situ from bistriflate 55 in the presence of cesium fluoride. Diepoxide 56 was obtained in 40% yield as a syn/anti mixture in a 1:1.7 ratio. Diepoxide 56 (as a diastereoisomeric mixture) was deposited on a Cu(111) surface by sublimation under UHV conditions and the molecular species

• –Alder reaction of naphthodiyne precursor 55 with isobenzofuran 61 to give monoepoxide 62 as a mixture of regioisomers. Further treatment of the latter with one equivalent of cesium fluoride allowed the regioselective Diels–Alder with the previous diene 61, to afford 63 as another mixture of position

• isomers. Finally, reaction of this bisaryne precursor with an excess cesium fluoride and bare isobenzofuran gave rise to the end-capped soluble precursor 59 via a double cycloaddition process. All polyepoxides 58–60 were deposited by sublimation on a Au(111) surface, triggering in some cases partial

Selective preparation of tetrasubstituted fluoroalkenes by fluorine-directed oxetane ring-opening reactions

• Clément Q. Fontenelle,
• Thibault Thierry,
• Romain Laporte,
• Emmanuel Pfund and
• Thierry Lequeux

Beilstein J. Org. Chem. 2020, 16, 1936–1946, doi:10.3762/bjoc.16.160

• phthalimidoyl substituents affording preferentially the Z-isomer of 1c. However, heteronucleophiles such as sodium azide, secondary amine and cesium fluoride were unsuccessfully tested. Finally, using the conditions developed by Burkhard and Carreira [26], the opening of the fluoroalkylidene-oxetane ring was

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• give excellent chemical yields with good enantioselectivities for products 57–59 (Scheme 14). Interestingly, this approach could be extended to the synthesis of amino acids using cesium fluoride in the presence of CO2 gas to afford 60 and 61. From the representative examples shown below, it appears

Synthesis of dipolar molecular rotors as linkers for metal-organic frameworks

• Sebastian Hamer,
• Fynn Röhricht,
• Marius Jakoby,
• Ian A. Howard,
• Xianghui Zhang,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1331–1338, doi:10.3762/bjoc.15.132

• acid 1 using cesium fluoride under a carbon dioxide atmosphere. Difluoro- and dicyanobenzothiadiazole compounds 2 and 3 Substituted benzothiadiazole derivatives are well studied in the literature and are of great interest in organic photovoltaics and electronics. As there are no reports of such

• -benzothiadiazole (10) could be obtained in a Sonogashira reaction with trimethylsilylacetylene. Conversion to the dicarboxylic acid 2 was achieved using cesium fluoride under a carbon dioxide atmosphere. Not quite as straightforward was the synthesis of the dicyano derivative 3. While the synthesis of 5,6-dicyano

• , conversion into the respective dicarboxylic acids 4 and 5 took place by reaction with cesium fluoride under a carbon dioxide atmosphere. Conclusion In summary, we reported here the synthesis of five dipolar rotors consisting of a push–pull-substituted phenylene core, with two ethynyl units in para-position

Convergent synthesis of the pentasaccharide repeating unit of the biofilms produced by Klebsiella pneumoniae

• Arin Gucchait,
• Angana Ghosh and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2019, 15, 431–436, doi:10.3762/bjoc.15.37

• -azidoethyl 4,6-O-benzylidene-β-D-glucopyranoside (8) [18], prepared from D-glucose, was selectively O-allylated at the 3-hydroxy group by treatment with dibutyltin oxide followed by allyl bromide in the presence of cesium fluoride [19] via the formation of a stannylene acetal to give 2-azidoethyl 3-O-allyl

Exploration of C–H and N–H-bond functionalization towards 1-(1,2-diarylindol-3-yl)tetrahydroisoquinolines

• Michael Ghobrial,
• Marko D. Mihovilovic and
• Michael Schnürch

Beilstein J. Org. Chem. 2014, 10, 2186–2199, doi:10.3762/bjoc.10.226

• . Carrying out the reaction in the absence of cesium fluoride resulted in no conversion. At 100 °C the reaction time could be reduced to 2 hours, however, the yield dropped to 62% due to increased decomposition. Hence, the reaction scope was investigated at 70 °C. Electron-rich 2-iodothiophene afforded a

Phosphinate-containing heterocycles: A mini-review

• Olivier Berger and
• Jean-Luc Montchamp

Beilstein J. Org. Chem. 2014, 10, 732–740, doi:10.3762/bjoc.10.67

• % yield by Li and coworkers via the reaction between diethyl 2-oxocyclohexylphosphonate (54) and benzyne generated from 2-(trimethylsilyl)phenyl triflate (55) and cesium fluoride [35]. 1,4,2-Oxazaphosphinane This series of compounds is only represented by few examples all generated through methodology

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• reaction conditions showed that cesium fluoride proved the best base. PhI(OAc)2 was the preferred oxidant over other hypervalent iodine compounds or sources of F+ or CF3+; additionally, the presence of a bis(oxazoline) as a ligand was beneficial to the reaction, as well as that of TEMPO to prevent

• fluoral and morpholine, following the procedure described by B. R. Langlois et al. [77] Moderate to good yields were observed when the reaction was carried out in diglyme with cesium fluoride as a base (Table 14). More recently, compounds derived from trifluoroacetic acid appeared to be a cheap and

• trifluoroacetate (MTFA) and cesium fluoride to generate the trifluoroacetate anion which decarboxylated under the reaction conditions (Figure 5). In most cases, the system does not necessitate the use of amine ligands excepted when aryl bromides are used instead of aryl iodides [81]. Aryl and heteroaryl products

Oxidative 3,3,3-trifluoropropylation of arylaldehydes

• Akari Ikeda,
• Masaaki Omote,
• Shiho Nomura,
• Miyuu Tanaka,
• Atsushi Tarui,
• Kazuyuki Sato and
• Akira Ando

Beilstein J. Org. Chem. 2013, 9, 2417–2421, doi:10.3762/bjoc.9.279

• reaction involves oxidative 3,3,3-trifluoropropylation of an arylaldehyde to afford 4,4,4-trifluoro-1-arylbutan-1-one. Keywords: cesium fluoride; organo-fluorine; 1,3-proton shift; trifluoromethyl; 3,3,3-trifluoropropenyl; Introduction Trifluoromethyl groups are an essential motif in pharmaceuticals

Discovery of practical production processes for arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides): Beginning of a new era of “super-trifluoromethyl” arene chemistry and its industry

• Teruo Umemoto,
• Lloyd M. Garrick and
• Norimichi Saito

Beilstein J. Org. Chem. 2012, 8, 461–471, doi:10.3762/bjoc.8.53

• industry. These new methods have been described in patents and patent applications [43][44][45][46][47][48]. Results and Discussion Recently we synthesized various arylsulfur trifluorides (ArSF3) by treatment of diaryl disulfides with chlorine in the presence of potassium [49][50] or cesium fluoride [50

• 13C NMR spectroscopy of the reaction solution. Arylsulfur chlorotetrafluorides were prepared in high yield by the reactions of diaryl disulfides with an excess amount of chlorine (ca. 7 mol or more per mole of the disulfide) in the presence of an excess amount of potassium or cesium fluoride (ca. 16

• ). Conclusion We have developed the first practical and economical method for the production of various arylsulfur pentafluorides and their higher homologues, which consists of the treatment of diaryl disulfides or aryl thiols with chlorine in the presence of potassium or cesium fluoride, followed by treatment