115262-00-5Relevant academic research and scientific papers
Fluorierte Elementorganika XX. Synthese von Fluormethyltrimethylsilanen
Broicher, Volker,Geffken, Detlef
, p. 315 - 320 (1990)
The synthesis of the fluoromethyltrimethylsilanes 4 > is described.The reaction of the tris-(diethylamino)-phosphane (1)/trimethylsilylhalogenide 3 system with the difluorodihalogenomethanes 2 gives the hitherto unknown 4a,b.The reduction of 4a,b and dichlorofluoromethyltrimethylsilane (13) with tris-(n-butyl)stannane (14) produces 4c-e in fair yields.
Halogenative difluorohomologation of ketones
Fedorov, Oleg V.,Kosobokov, Mikhail D.,Levin, Vitalij V.,Struchkova, Marina I.,Dilman, Alexander D.
, p. 5870 - 5876 (2015/06/16)
A method for the difluorohomologation of ketones accompanied by halogenation of a C-H bond is described. The reaction involves silylation, difluorocarbene addition using Me3SiCF2Br activated by a bromide ion, and halogenation of intermediate cyclopropanes with N-bromo- or N-iodosuccinimide. The whole process is performed without isolation of intermediates. The resulting α,α-difluoro-β-halo-substituted ketones can be readily converted into fluorine containing pyrazole derivatives and oxetanes.
Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine
Wang, Fei,Li, Lingchun,Ni, Chuanfa,Hu, Jinbo
, p. 344 - 351 (2014/03/21)
Background: 1,1-Difluoroalkenes cannot only be used as valuable precursors for organic synthesis, but also act as bioisosteres for enzyme inhibitors. Among various methods for their preparation, the carbonyl olefination with difluoromethylene phosphonium ylide represents one of the most straightforward methods. Results: The combination of (chlorodifluoromethyl)trimethylsilane (TMSCF2Cl) and triphenylphosphine (PPh3) can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyl)trimethylsilane (TMSCF2Br) and (trifluoromethyl)trimethylsilane (TMSCF3) in this reaction. Conclusion: Similar to many other Wittig-type gem-difluoroolefination reactions in the presence of PPh3, the reaction of TMSCF2Cl with aldehydes and activated ketones is effective.
Nucleophilic bromodifluoromethylation of iminium ions
Tsymbal, Artem V.,Kosobokov, Mikhail D.,Levin, Vitalij V.,Struchkova, Marina I.,Dilman, Alexander D.
, p. 7831 - 7835 (2015/03/18)
A method for bromodifluoromethylation of iminium ions using Me3SiCF2Br is described. The reaction involves room temperature activation of the silicon reagent by HMPA to generate difluorocarbene, which upon interacting with excess of bromide ion provides bromodifluoromethyl carbanionic species. The iminium electrophiles are generated in situ from aldehydes, secondary amines, proton sponge, and silyl triflate. The reaction can be extended for introduction of chlorodifluoromethyl and iododifluoromethyl groups.
Preparation of and fluoroalkylation with (chlorodifluoromethyl)trimethylsilane, difluorobis(trimethylsilyl)methane, and 1,1,2,2-tetrafluoro-1,2-bis(trimethylsilyl)ethane
Yudin, Andrei K.,Prakash, G. K. Surya,Deffieux, Denis,Bradley, Michael,Bau, Robert,Olah, George A.
, p. 1572 - 1581 (2007/10/03)
CF2BrCl reacts with aluminum/N-methylpyrrolidinone in the presence of chlorotrimethylsilane to give Me3SiCF2Cl in high yield. Similarly, CF2Br2 gives Me3SiCF2Br with bromotrimethylsilane. Chlorodifluoromethylation of aldehydes using Me3SiCF2Cl and a catalytic amount of TBAF in polar solvents occurs at room temperature, providing difluoromethylated alcohols in two steps. Electroreduction of Me3SiCF2Cl in the presence of chlorotrimethylsilane gives Me3SiCF2SiMe3 (anion-derived product) and Me3SiCF2CF2SiMe3 (radical-derived product). Using THF/HMPA strongly favors the former, whereas THF/TDA-1 (tris(3,6-dioxaheptyl)amine) the latter. Me3SiCF2SiMe3 difluoromethylates aldehydes acting as a difluoromethylene dianion ('CF22-'/equivalent), whereas Me3SiCF2CF2SiMe3 acts at room temperature as an in situ source for the perfluorovinyl anion (due to β-elimination of fluorotrimethylsilane). However, at low temperature the elimination pathway is suppressed and tetrafluoroethylene dianion ('-CF2CF2-'/equivalent) behavior is observed. The structure of Me3SiCF2CF2SiMe3 was analyzed by X-ray diffraction. All of the studied fluoroalkylating reagents are moisture- and air-stable and can be readily obtained from a single convenient precursor (CF2BrCl).
