596826-81-2Relevant academic research and scientific papers
A convenient photocatalytic fluorination of unactivated C-H bonds
Halperin, Shira D.,Fan, Hope,Chang, Stanley,Martin, Rainer E.,Britton, Robert
supporting information, p. 4690 - 4693 (2014/05/20)
Fluorination reactions are essential to modern medicinal chemistry, thus providing a means to block site-selective metabolic degradation of drugs and access radiotracers for positron emission tomography imaging. Despite current sophistication in fluorination reagents and processes, the fluorination of unactivated C-H bonds remains a significant challenge. Reported herein is a convenient and economic process for direct fluorination of unactivated C-H bonds that exploits the hydrogen abstracting ability of a decatungstate photocatalyst in combination with the mild fluorine atom transfer reagent N-fluorobenzenesulfonimide. This operationally straightforward reaction provides direct access to a wide range of fluorinated organic molecules, including structurally complex natural products, acyl fluorides, and fluorinated amino acid derivatives. The direct fluorination of unactivated C(sp3)-H bonds is catalyzed by the inexpensive photocatalyst tetrabutylammonium decatungstate (TBADT). This convenient reaction provides direct access to a wide range of fluorinated organic molecules, including structurally complex natural products, acyl fluorides, and fluorinated amino acids.
C-HALOGEN BOND FORMATION
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Page/Page column 0151; 0183-0187, (2013/03/26)
Methods of halogenating a carbon containing compound having an sp3 C-H bond are provided. Methods of fluorinating a carbon containing compound comprising halogenation with Cl or Br followed by nucleophilic substitution with F are provided. Methods of direct oxidative C-H fluorination of a carbon containing compound having an sp3 C-H bond are provided. The halogenated products of the methods are provided.
Oxidative aliphatic C-H fluorination with fluoride ion catalyzed by a manganese porphyrin
Liu, Wei,Huang, Xiongyi,Groves, John T.,Cheng, Mu-Jeng,Nielsen, Robert J.,Goddard III, William A.
, p. 1322 - 1325,4 (2020/08/31)
Despite the growing importance of fluorinated organic compounds in drug development, there are no direct protocols for the fluorination of aliphatic C-H bonds using conveniently handled fluoride salts. We have discovered that a manganese porphyrin complex catalyzes alkyl fluorination by fluoride ion under mild conditions in conjunction with stoichiometric oxidation by iodosylbenzene. Simple alkanes, terpenoids, and even steroids were selectively fluorinated at otherwise inaccessible sites in 50 to 60% yield. Decalin was fluorinated predominantly at the C2 and C3 methylene positions. Bornyl acetate was converted to exo-5-fluoro-bornyl acetate, and 5a-androstan-17-one was fluorinated selectively in the A ring. Mechanistic analysis suggests that the regioselectivity for C-H bond cleavage is directed by an oxomanganese(V) catalytic intermediate followed by F delivery via an unusual manganese(IV) fluoride that has been isolated and structurally characterized.
Synthesis of fluorinated cycloalkyl N-phenylcarbamates and their microbial defluorination/oxygenation by Beauveria bassiana
Haufe, Guenter,Pietz, Sylke,Woelker, Doerthe,Froehlich, Roland
, p. 2166 - 2175 (2007/10/03)
Earlier investigations showed that cycloalkyl N-phenylcarbamates were hydroxylated by the fungus Beauveria bassiana predominantly in the 4-position relative to the electron-rich substituent. In cases involving fluorinated methylene groups potentially capable of hydroxylation, however, defluorination and formation of a ketone was observed. The formation of the ketone can be explained by primary hydroxylation to forman unstable geminal fluorohydrin, which is subsequently dehydrofluorinated. Wiley-VCH Verlag GmbH & Co. KGaAA, 69451 Weinheim, Germany, 2003.
