20083-07-2Relevant academic research and scientific papers
Diazaphospholene-Catalyzed Hydrodefluorination of Polyfluoroarenes with Phenylsilane via Concerted Nucleophilic Aromatic Substitution
Zhang, Jingjing,Zhao, Xiao,Yang, Jin-Dong,Cheng, Jin-Pei
supporting information, p. 294 - 300 (2022/01/03)
The metal-free catalytic C-F bond activation of polyfluoroarenes was achieved with diazaphospholene as the catalyst and phenylsilane as the terminal reductant. Density functional theory calculations suggested a concerted nucleophilic aromatic substitution mechanism.
Nickel-Catalyzed C-H Silylation of Arenes with Vinylsilanes: Rapid and Reversible β-Si Elimination
Elsby, Matthew R.,Johnson, Samuel A.
supporting information, p. 9401 - 9407 (2017/07/22)
The reaction of C6F5H and H2C=CHSiMe3 with catalytic [iPr2Im]Ni(2-H2C=CHSiMe3)2 (1b) exclusively forms the C-H silylation product C6F5SiMe3 with ethylene as a byproduct ([iPr2Im] = 1,3-di(isopropyl)imidazole-2-ylidene). Catalytic C-H bond silylation is facile with partially fluorinated aromatic substrates containing two ortho fluorine substituents adjacent to the C-H bond and 1,2,3,4-tetrafluorobenzene. Less fluorinated substrates react slower. Under the same reaction conditions, catalytic [IPr]Ni(η2-H2C=CHSiMe3)2 (1a) ([IPr] = 1,3-bis[2,6-diisopropylphenyl]-1,3-dihydro-2H-imidazol-2-ylidene) provided only the alkene hydroarylation product C6F5CH2CH2SiMe3. Mechanistic studies reveal that the C-H activation and β-Si elimination steps are reversible under catalytic conditions with both catalysts 1a and 1b. With catalytic 1a, reversible ethylene loss after β-Si elimination was also observed despite its inability to catalyze C-H silylation; the reductive elimination step to form the silylation product is much slower than reductive elimination to form the alkene hydroarylation product. Reversible ethylene loss was not observed with 1b, which suggests that the rate-limiting step in the reaction is neither C-H activation nor β-Si elimination but either ethylene loss or reductive elimination of cis-disposed aryl and SiMe3 moieties.
Reactions of polyfluoroaromatic compounds with electrophilic agents in the presence of tris(dialkylamino)phosphine: 6. * Reactions of halogenotetrafluorobenzenes RC6F4X (X = Cl, Br, or I) with chlorotrimethylsilane
Bardin
, p. 780 - 785 (2007/10/03)
The rate of replacement of the halogen atom in isomers of RC6F4X (X = Cl, Br, or I) by the SiMe3 group under the action of Me3SiCl and P(NEt2)3 depends on the nature and the mutual arrangement of the substituents X and R. In addition to silyldehalogenation, compounds C6HF4X (X = Br or I) undergo silyldeprotonation and reduction to tetrafluorobenzenes.
Reactions of trimethylsilylpentafluorobenzene and triethylgermylpentafluorobenzene with nucleophilic reagents
Bardin, V.V.,Rogoza, L.N.,Stennikova, I.V.,Furin, G.G.
, p. 165 - 177 (2007/10/02)
This paper reports the results of studies on the reactions of trialkylsilyl-and germylpentafluorobenzenes with O-,N,- S- and C-nucleophiles, and with LiAlH4.Depending on the nature of the nucleophilic reagent, its attack is oriented towards a heteroatom (RO-,RS-), the C-4 atom of the pentafluorophenyl ring (BuLi, LiAlH4, piperidyl-lithium) or at both electrophilic centres (piperidine, RS-.
Fluoride Ion-Catalyzed Generation and Carbonyl Addition of α-Halo Carbanions Derived from α-Halo Organosilicon Compounds
Fujita, Makoto,Obayashi, Michio,Hiyama, Tamejiro
, p. 4135 - 4146 (2007/10/02)
The title carbanion species are generated from the corresponding α-haloorganosilicon compounds by the action of a catalytic amount of tris(diethylamino)sulfonium difluorotrimethylsilicate and are found to undergo addition to aldehyde carbonyl efficiently at ambient temperature.The synthetic potential of the reaction is demonstrated by application to the synthesis of some insecticides.
