443-88-9Relevant academic research and scientific papers
Azoacetylenes for the Synthesis of Arylazotriazole Photoswitches
Anderl, Felix,Balkenhohl, Moritz,Carreira, Erick M.,Fink, Moritz,Pfaff, Patrick
, p. 14495 - 14501 (2021/09/18)
We report a modular approach toward novel arylazotriazole photoswitches and their photophysical characterization. Addition of lithiated TIPS-acetylene to aryldiazonium tetrafluoroborate salts gives a wide range of azoacetylenes, constituting an underexplored class of stable intermediates.In situdesilylation transiently leads to terminal arylazoacetylenes that undergo copper-catalyzed cycloadditions (CuAAC) with a diverse collection of organoazides. These include complex molecules derived from natural products or drugs, such as colchicine, taxol, tamiflu, and arachidonic acid. The arylazotriazoles display near-quantitative photoisomerization and long thermalZ-half-lives. Using the method, we introduce for the first time the design and synthesis of a diacetylene platform. It permits implementation of consecutive and diversity-oriented approaches linking two different conjugants to independently addressable acetylenes within a common photoswitchable azotriazole. This is showcased in the synthesis of several photoswitchable conjugates, with potential applications as photoPROTACs and biotin conjugates.
Expanding the Balz–Schiemann Reaction: Organotrifluoroborates Serve as Competent Sources of Fluoride Ion for Fluoro-Dediazoniation
Mohy El Dine, Tharwat,Sadek, Omar,Gras, Emmanuel,Perrin, David M.
supporting information, p. 14933 - 14937 (2018/09/25)
The Balz–Schiemann reaction endures as a method for the preparation of (hetero)aryl fluorides yet is eschewed due to the need for harsh conditions or high temperatures along with the need to isolate potentially explosive diazonium salts. In a departure from these conditions, we show that various organotrifluoroborates (RBF3?s) may serve as fluoride ion sources for solution-phase fluoro-dediazoniation in organic solvents under mild conditions. This methodology was successfully extended to a one-pot process obviating aryl diazonium salt isolation. Sterically hindered (hetero)anilines are fluorinated under unprecedentedly mild conditions in good-to-excellent yields. Taken together, this work expands the repertoire of RBF3?s to act as fluorine ion sources in an update to the classic Balz–Schiemann reaction.
Fluorination of aryl boronic acids using acetyl hypofluorite made directly from diluted fluorine
Vints, Inna,Gatenyo, Julia,Rozen, Shlomo
, p. 11794 - 11797 (2014/01/06)
Aryl boronic acids or pinacol esters containing EDG were converted in good yields and fast reactions to the corresponding aryl fluorides using the readily obtainable solutions of AcOF. In reactions with aryl boronic acids containing EWG at the para position, there are two competing forces: one directing the fluorination to take place ortho to the boronic acid and the other, toward an ipso substitution. With EWG meta to the boronic acid, substitution ipso to the boron moiety takes place in good yields.
Cu-catalyzed fluorination of diaryliodonium salts with KF
Ichiishi, Naoko,Canty, Allan J.,Yates, Brian F.,Sanford, Melanie S.
supporting information, p. 5134 - 5137 (2013/10/22)
A mild Cu-catalyzed nucleophilic fluorination of unsymmetrical diaryliodonium salts with KF is described. This protocol preferentially fluorinates the smaller aromatic ligand on iodine(III). The reaction exhibits a broad substrate scope and proceeds with high chemoselectivity and functional group tolerance. DFT calculations implicate a CuI/CuIII catalytic cycle.
Copper-mediated fluorination of aryl iodides
Fier, Patrick S.,Hartwig, John F.
supporting information; experimental part, p. 10795 - 10798 (2012/08/07)
The synthesis of aryl fluorides has been studied intensively because of the importance of aryl fluorides in pharmaceuticals, agrochemicals, and materials. The stability, reactivity, and biological properties of aryl fluorides can be distinct from those of the corresponding arenes. Methods for the synthesis of aryl fluorides, however, are limited. We report the conversion of a diverse set of aryl iodides to the corresponding aryl fluorides. This reaction occurs with a cationic copper reagent and silver fluoride. Preliminary results suggest this reaction is enabled by a facile reductive elimination from a cationic arylcopper(III) fluoride.
Synthesis of aryl fluorides on a solid support and in solution by utilizing a fluorinated solvent
Doebele, Marion,Vanderheiden, Sylvia,Jung, Nicole,Braese, Stefan
scheme or table, p. 5986 - 5988 (2010/10/01)
(Figure Presented) F for fast: The perfluorinated solvent C 6F14 is the key to a new variant of the BalzSchiemann reaction for the synthesis of fluorinated arenes. Triazenes are converted into fluoroarenes under mild con-ditions on a support and in solution (see scheme). The method is straightforward and inexpensive, and yields previously difficult-to-prepare fluoroarenes in high purity.
Efficient synthesis of aryl fluorides
Anbarasan, Pazhamalai,Neumann, Helfried,Beller, Matthias
experimental part, p. 2219 - 2222 (2010/06/17)
Chemical Equation Presented Creating C-F bonds: A novel electrophilic fluorination of aryl and heteroaryl Crignard reagents has been discovered and was used for the efficient synthesis of various aryl fluoride derivatives (see picture; THF = tetrahydrofuran).
Fluorination of aromatic compounds with N-fluorobenzenesulfonimide under solvent-free conditions
Andreev,Borodkin,Shubin
scheme or table, p. 1468 - 1473 (2010/03/24)
Reactions of N-fluorobenzenesulfonimide with methylbenzenes, phenols, and phenol ethers were studied under solvent-free conditions. The rate constant ratio for the reactions with mesitylene and durene indicates polar mechanism of the process. Solvent-free fluorination of aromatic compounds with N-fluorobenzenesulfonimide in some cases is more selective than reactions with other N-F reagents in a solvent.
Conformational flexibility of tetralactam macrocycles and their intermolecular hydrogen-bonding patterns in the solid state
Zhu, Sascha S.,Nieger, Martin,Daniels, Joerg,Felder, Thorsten,Kossev, Iordan,Schmidt, Thomas,Sokolowski, Moritz,Voegtle, Fritz,Schalley, Christoph A.
experimental part, p. 5040 - 5046 (2009/12/26)
Despite their rigid scaffold, tetralactam macrocycles (TLMs) display a remarkable degree of conformational flexibility, as revealed by analysis of the corresponding X-ray crystal structures. This flexibility is not limited to the rotatability of the TLM amide groups but also applies to the m-xylene rings, and it thus has a great impact on the overall shape of the macrocycle cavity. The conformational properties of the TLMs give rise to a broad variety of intermolecular hydrogen-bonding patterns, including infinite ladders, an interesting catemer motif, and short C-H... O=C hydrogen bonds. These results are in accord with previous theoretical calculations, support a structural model proposed earlier for an interpretation of scanning tunneling microscopy images, and substantially contribute to the understanding of the adaptability of macrocyclic scaffolds, which is crucial for guest binding or templated syntheses with TLMs.
Preparation process of fluorine substituted aromatic compound
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, (2008/06/13)
A preparation process of a fluorine substituted aromatic compound comprising reacting an alkali metal or alkali earth metal salt of an aromatic compound having a hydroxy group with an organic fluorinating agent is disclosed. As a representative fluorinating agent, a bis-dialkylamino-difluoromethane compound, for example, 2,2′-difluoro-1,3-dimethylimidazolidine, is exemplified. According to the process, an industrially useful fluorinated aromatic compound, for example, a fluorobenzene, a fluorine substituted benzophenone, a fluorine substituted diarylsulfone can be prepared with ease in economy without specific equipment.
