451-80-9Relevant academic research and scientific papers
A new alkylation of aryl alcohols by boron trifluoride etherate
Jumbam, Ndze Denis,Maganga, Yamkela,Masamba, Wayiza,Mbunye, Nomthandazo I.,Mgoqi, Esethu,Mtwa, Sphumusa
, (2019/10/28)
The ethylation of aryl alcohols by an ethyl moiety of boron trifluoride etherate is described. The reaction proceeded cleanly and afforded good yields of the corresponding aryl ethyl ethers. It tolerated the presence of functional groups such as aryl, alkyl, halogens, nitro, nitrile, and amino. However, the presence of amino or nitro groups ortho to a hydroxyl group of an aryl compound drastically reduced the yields of the anticipated products due to the chelation of the aforementioned functional groups with boron trifluoride etherate. A nitrogen atom in the aromatic ring system, as exemplified by hydroxypyridine and 8-hydroxyquinoline, completely inhibited the reaction. Resorcinol, hydroquinone, and aryl alcohols with aldehyde functions decomposed under the reaction conditions.
Transition-Metal-Free C-C, C-O, and C-N Cross-Couplings Enabled by Light
Liu, Wenbo,Li, Jianbin,Querard, Pierre,Li, Chao-Jun
, p. 6755 - 6764 (2019/05/06)
Transition-metal-catalyzed cross-couplings to construct C-C, C-O, and C-N bonds have revolutionized chemical science. Despite great achievements, these metal catalysts also raise certain issues including their high cost, requirement of specialized ligands, sensitivity to air and moisture, and so-called "transition-metal-residue issue". Complementary strategy, which does not rely on the well-established oxidative addition, transmetalation, and reductive elimination mechanistic paradigm, would potentially eliminate all of these metal-related issues. Herein, we show that aryl triflates can be coupled with potassium aryl trifluoroborates, aliphatic alcohols, and nitriles without the assistance of metal catalysts empowered by photoenergy. Control experiments reveal that among all common aryl electrophiles only aryl triflates are competent in these couplings whereas aryl iodides and bromides cannot serve as the coupling partners. DFT calculation reveals that once converted to the aryl radical cation, aryl triflate would be more favorable to ipso substitution. Fluorescence spectroscopy and cyclic voltammetry investigations suggest that the interaction between excited acetone and aryl triflate is essential to these couplings. The results in this report are anticipated to provide new opportunities to perform cross-couplings.
Synthesis of aryl fluorides from potassium aryltrifluoroborates and selectfluor mediated by iron(III) chloride
Dubbaka, Srinivas Reddy,Gadde, Satyanarayana,Narreddula, Venkateswara Reddy
, p. 854 - 860 (2015/03/14)
The synthesis of fluorinated arenes by the iron-mediated fluorination of potassium aryltrifluoroborates with Selectfluor and potassium fluoride is described. The fluorination reaction uses commercially available reagents and without requiring the addition
Asymmetric synthesis of (+)-(S,S)-reboxetine via a new (S)-2- (hydroxymethyl)morpholine preparation
Brenner, Eric,Baldwin, Ronald M.,Tamagnan, Gilles
, p. 937 - 939 (2007/10/03)
(Chemical Equation Presented) (S,S)-Reboxetine was synthesized stereospecifically in 30% overall yield and 99% ee in eight steps. Key steps were selective oxidation of an N-protected hydroxymethylmorpholine and aryl-chromium-mediated aromatic nucleophilic substitution.
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.
A Novel Electrophilic Fluorination of Activated Aromatic Rings Using Acetyl Hypofluorite, Suitable also for Introducing (18)F into Benzene Nuclei
Lerman, Ori,Yitzhak, Tor,Hebel, David,Rozen, Shlomo
, p. 806 - 813 (2007/10/02)
Acetyl hypofluorite (1) is a new compound that serves as a novel electrophilic fluorinating agent.It is special in the sense that, while it is very reactive, it is still a milder reagent than other fluoroxy compounds such as CF3OF or CF3COOF.It is synthesized directly from elemental fluorine and is used without any isolation or purification.The hypofluorite 1 reacts efficiently and selectively with activated aromatic rings,particularly phenol and aniline derivatives after suitable protection of the hydroxyl and the amino groups.The net result of the reaction is partly according to classical aromatic electrophilic substitution.Unlike such a substitution, however, the electrophilic fluorine atom of 1 substitutes mainly an ortho hydrogen and only occasionally small amounts of p-fluoro derivatives are found.Evidence supports the mechanism for this aromatic fluorination as being mainly an addition-elimination one.In many cases the electrophilic aromatic fluorinations can replace the classical 60-year-old Balz-Schiemann method, which until today is probably the most used procedure.Since aromatic fluorination with 1 is a very fast reaction and since 1 is produced directly from elemental fluorine, this is probably one of the best ways for introduction of the short-living radioisotope (18)F into activated aromatic rings.This will greatly encourage the synthesis of compounds suitable for use in the rapidly developing field of positron emitting transaxial tomography, which in itself depends on the efficient and easy supply of compounds possessing positron emitting isotopes.
