7073-98-5Relevant academic research and scientific papers
Oxidative C-C bond formation reactivity of organometallic Ni(II), Ni(III), and Ni(IV) complexes
Watson, Michael B.,Rath, Nigam P.,Mirica, Liviu M.
, p. 35 - 38 (2017/05/16)
The use of the tridentate ligand 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3tacn) and the cyclic alkyl/aryl C-donor ligand-CH2CMe2-o-C6H4-(cycloneophyl) allows for the synthesis of isolable organometallic NiII, NiIII, and NiIV complexes. Surprisingly, the fivecoordinate NiIII complex is stable both in solution and the solid state, and exhibits limited C-C bond formation reactivity. Oxidation by one electron of this NiIII species generates a six-coordinate NiIV complex, with an acetonitrile molecule bound to Ni. Interestingly, illumination of the NiIV complex with blue LEDs results in rapid formation of the cyclic C-C product at room temperature. This reactivity has important implications for the recently developed dual Ni/photoredox catalytic systems proposed to involve high-valent organometallic Ni intermediates. Additional reactivity studies show the corresponding NiII species undergoes oxidative addition with alkyl halides, as well as rapid oxidation by O2, to generate detectable NiIII and/or NiIV intermediates and followed by C-C bond formation.
Non-catalytic conversion of C-F bonds of benzotrifluorides to C-C bonds using organoaluminium reagents
Terao, Jun,Nakamura, Misaki,Kambe, Nobuaki
scheme or table, p. 6011 - 6013 (2010/11/16)
A facile method for the conversion of C-F bonds of benzotrifluorides to C-C bonds has been developed using aluminium reagents in the absence of catalysts.
PROCESS FOR HALOGENATION OF BENZENE AND BENZENE DERIVATIVES
-
Page/Page column 19; 20, (2008/06/13)
In a process of halogenation of benzene or benzene derivatives, di-substituted halobenzene derivatives having para-aromatic compounds or tri-substituted halobenzene derivatives having 1,2,4-substituted aromatic compounds are selectively produced. In halogenation of benzene or benzene derivatives, a fluorine-containing zeolite catalyst such as L-type zeolite, or a zeolite catalyst having the crystal size of at most 100 nm is used. The reaction is preferably effected in the presence of a solvent, and the solvent is preferably a halogenated compound.
Electrophilic aromatic chlorination and haloperoxidation of chloride catalyzed by polyfluorinated alcohols: A new manifestation of template catalysis
Ben-Daniel, Revital,De Visser, Samuel P.,Shaik, Sason,Neumann, Ronny
, p. 12116 - 12117 (2007/10/03)
We have demonstrated that a polyfluorinated alcohol, 2,2,2-trifluoroethanol, solvent enables haloperoxidase type activity and the oxychlorination of arenes (benzene and its alkylated derivatives) without a metal catalyst. The polyfluorinated alcohol has a dual function; it catalyzes electrophilic chlorination of less reactive arenes by several orders of magnitude and oxidation of chloride at lower H+ concentrations. DFT calculations show that a complementary charge template in the transition state explains the catalysis of the electrophilic chlorination. Copyright
Versatility of Zeolites as Catalysts for Ring or Side-Chain Aromatic Chlorinations by Sulfuryl Chloride
Delaude, Lionel,Laszlo, Pierre
, p. 5260 - 5269 (2007/10/02)
Zeolites catalyze chlorination of aromatics by sulfuryl chloride SO2Cl2.It is possible by an appropriate choice of the catalyst to effect at will, with very high selectivity, either the ring or the side-chain chlorination.Zeolite ZF520 is the choice catalyst for the former, because of its high Broensted acidity.Zeolite NaX (13X) is a fine catalyst for the latter, free-radical chlorination; the reaction is best effected in the presence of a light source; the catalyst can be reused many times with no loss in activity.Both reaction modes, the ionic (ring chlorination)and the radical (side-chain substitution), are likely to occur outside of the channel network in the microporous solid.The effects of various experimental factors - such as the nature of the solvent, the reaction time and temperature, the Broensted acidity of the solid support, the presence of radical inhibitors, and the quantity of catalysts - were investigated.The procedures resulting from this study are very easy to implement in practice and are quite effective.
Halogenation Using Quaternary Ammonium Polyhalides. XIX. Aromatic Chlorination of Arenes with Benzyltrimethylammonium Tetrachloroiodate
Kajigaeshi, Shoji,Ueda, Yasuhiro,Fujisaki, Shizuo,Kakinami, Takaaki
, p. 2096 - 2098 (2007/10/02)
The reaction of arenes with a calculated amount of benzyltrimethylammonium tetrachloroiodate in acetic acid at room temperature or at 70 deg C gave nuclear chloro-substituted arenes in fairly good yields.
Highly para-Selective Mono-Chlorination of Aromatic Compounds Under Mild Conditions by t-Butyl Hypochlorite in the Presence of Zeolites
Smith, Keith,Butters, Michael,Nay, Barry
, p. 1157 - 1158 (2007/10/02)
t-Butyl hypochlorite supported on H(1+), Na(1+) faujasite X (zeolite X) produces para-selective monochlorination of alkyl-, phenyl-, and halobenzenes under mild conditions; for example, chlorobenzene in acetonitrile (at 40 deg C) is chlorinated in high yield of isolated product (92percent) to give dichlorobenzene with an isomer ratio 97percent para/3percent ortho.
New Reagent Systems for Electrophilic Chlorination of Aromatic Compounds: Organic Chlorine-Containing Compounds in the Presence of Silica
Smith, Keith,Butters, Michael,Paget, Walter E.,Nay, Barry
, p. 1155 - 1156 (2007/10/02)
In the presence of silica, a number of chlorine-containing organic compounds, such as N,N-dichlorourethane, dichloramine-T, and t-butyl hypochlorite, become active electrophilic reagents capable of controlled monochlorination of aromatic compounds under mild conditions; for example, t-butyl hypochlorite/silica chlorinates alkylbenzenes, naphthalene, and anisole readily at 25 deg C; N,N-dichlorourethane/silica chlorinates benzene within 2 days 50 deg C.
Temperature Effects on the Selectivity of ?-Radicals
Giese, Bernd,Stellmach, Joachim
, p. 3294 - 3302 (2007/10/02)
Bent ?-radicals 3a-i, generated from alkylmercuric salts 1 and/or peresters 2, were treated with a BrCCl3/CCl4 competition system at different temperatures.Exner-analysis of these selectivity data (table 1) shows, that radicals of sp2 type 3a-d and bridgehead radicals 3e-i follow different isoselective relationships (figure 1, 2).Reversal of the selectivity row occurs at 310 and 210 K, respectively.Above of these isoselective temperatures less shielded radicals are more selective than more shielded radicals because entropy effects overcompensate enthalpy effects (table 2).Comparison with ?-radicals 6 shows, that each type of carbon radicals follows an isoselective relationship by its own.
REGIOSELECTIVE PARA-CHLORINATION OF ALKYLBENZENES ON CHEMICALLY-MODIFIED SILICA SURFACES
Konishi, Hisatoshi,Yokota, Kiyoshi,Ichihashi, Yuji,Okano, Tamon,Kiji, Jitsuo
, p. 1423 - 1426 (2007/10/02)
Chlorination of alkylbenzenes was carried out with chlorine in carbon tetrachloride in the presence of chemically-modified silica catalysts.The para/ortho ratios were remarkably higher than those obtained in the FeCl3-catalyzed chlorination. t-Butylbenzene was chlorinated at para-position almost exclusively.The catalyst could be reused several times.
